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1
Sun, Hongyan, Kelly Kopp, and Roger Kjelgren. "Water-efficient Urban Landscapes: Integrating Different Water Use Categorizations and Plant Types." HortScience 47, no. 2 (February 2012): 254–63. http://dx.doi.org/10.21273/hortsci.47.2.254.
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Little research has examined water requirements of entire irrigated urban landscapes integrating different types of plants. Three landscape treatments integrating different types of plants—woody, herbaceous perennial, turf—and putative water use classifications—mesic, mixed, xeric—were grown in large drainage lysimeters. Each landscape plot was divided into woody plant, turf, and perennial hydrozones and irrigated for optimum water status over 2 years and water use measured using a water balance approach. For woody plants and herbaceous perennials, canopy cover rather than plant type or water use classification was the key determinant of water use relative to reference evapotranspiration (ETo) under well-watered conditions. For turf, monthly evapotranspiration (ETa) followed a trend linearly related to ETo. Monthly plant factors (Kp) for woody plants, perennials, and turf species under well-watered conditions in this study ranged from 0.3 to 0.9, 0.2 to 0.5, and 0.5 to 1.2, respectively. Adjusted Kp for each hydrozone was calculated based on landscaped area covered by plant types as a percent of total area, and landscape factor (Kl) was calculated based on adjusted Kp for each landscape treatment. Overall, Kl relative to ETo ranged from 0.6 to 0.8 for three water use classifications.
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Hiebert-Giesbrecht, Mickel Randolph, Candelaria Yuseth Novelo-Rodríguez, Gabriel Rolando Dzib, Luz María Calvo-Irabién, Georg von Arx, and Luis Manuel Peña-Rodríguez. "Herb-chronology as a tool for determining the age of perennial forbs in tropical climates." Botany 96, no. 1 (January 2018): 73–78. http://dx.doi.org/10.1139/cjb-2017-0167.
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Age in wild plant populations is one of the most elusive developmental parameters in plant biology. Several approaches take advantage of a plant’s morphological traits to determine developmental stages or plant age. Annual growth rings forming in woody tissues of perennial plants are one of the traits that have been widely used to determine the age of trees (dendrochronology) and, more recently, herbaceous perennials (herb-chronology). In temperate, alpine, and arctic climates, it has been reported that seasonal variations in climate lead to the formation of annual growth rings in herbaceous perennial forbs; however, to date, no similar studies have been carried out on plants from tropical regions. We have investigated the applicability of herb-chronology on the tropical plant Pentalinon andrieuxii (Müll. Arg.) B.F. Hansen & Wunderlin, a native vine of the Yucatan peninsula. Our results show that herb-chronology is a potentially useful tool in determining the age of plants growing in tropical climates.
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Calvo, L., R. Tarrega, and E. Luis. "Regeneration in Quercus Pyrenaica Ecosystems After Surface Fires." International Journal of Wildland Fire 1, no. 4 (1991): 205. http://dx.doi.org/10.1071/wf9910205.
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Early post-fire structural dynamics in three Quercus pyrenaica communities after intense fires was studied. In the first year there is a marked domination of perennial species (herbaceous or woody); afterwards, herbaceous species tend to decrease in importance and ligneous species increase. Changes in species diversity were analysed as an indicator of recovery and stability in the communities. An increase was observed in the second year, and then diversity was maintained or reduced slightly in the third and fourth years. Spatial heterogeneity tends to diminish with time.
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Carlquist, S., E. L. Schneider, and R. B. Miller. "Wood and Bark Anatomy of Argemone (Papaveraceae)." IAWA Journal 15, no. 3 (1994): 247–55. http://dx.doi.org/10.1163/22941932-90000603.
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Wood anatomy of Argemone fruticosa, sole shrubby species of the genus, is distinctive in having growth rings, thick-walled libriform fibres, thick-walled ray cells with large intercellular spaces, vessels with grooves interconnecting pit apertures, and restriction of vessels to central portions of fascicular areas. Most of these features are related to the xeric ecology of this species. Argemone turnerae is an herbaceous perennial with large roots and sterns, the wood of which exhibits features distinctively related to this habit, including succulence (axial parenchyma substitutes for libriform fibres). Both species of Argemone share such features as storied wood structure and absence of uniseriate rays, which are infrequent in dicotyledons at large but common in other Papaveraceae. Wood data are not decisive in indicating whether the ancestors of Argemone or Papaveraceae were woody or herbaceous, but several features indicative of paedomorphosis can be found in the wood. Bark of Argemone is briefly described.
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Johnson, Gregg A., Donald L. Wyse, and Craig C. Sheaffer. "Yield of perennial herbaceous and woody biomass crops over time across three locations." Biomass and Bioenergy 58 (November 2013): 267–74. http://dx.doi.org/10.1016/j.biombioe.2013.10.013.
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Knuth, Melinda, Bridget K. Behe, Charles R. Hall, Patricia Huddleston, and R. Thomas Fernandez. "Consumer Perceptions of Landscape Plant Production Water Sources and Uses in the Landscape during Perceived and Real Drought." HortTechnology 28, no. 1 (February 2018): 85–93. http://dx.doi.org/10.21273/horttech03893-17.
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Water is becoming scarcer as world population increases and will be allocated among competing uses. Some of that water will go toward sustaining human life, but some will be needed to install and support landscape plants. Thus, future water resource availability may literally change the American landscape. Recent research suggests that consumers’ attitudes and behavior toward potable water supplies have changed in other countries because of greater social awareness and increasingly widespread exposure to drought conditions. We conducted an online survey of 1543 U.S. consumers to assess their perceptions about landscape plants, the water source used to produce them, and plant water needs to become established in the landscape. Using two separate conjoint designs, we assessed their perceptions of both herbaceous and woody perennials. Consumers placed greater relative importance on water source in production over water use in the landscape for both herbaceous and woody perennials included in this study. They preferred (had a higher utility score for) fresh water over recycled water and least preferred a blend of fresh with recycled water for perennials and recycled water used for woody perennial production. In addition, the group that did not perceive a drought but experienced one placed a higher value (higher utility score) on nursery plants grown with fresh water compared with those which were actually not in drought and did not perceive one. Educational and promotional efforts may improve the perception of recycled water to increase the utility of that resource. Promoting the benefits of low water use plants in the landscape may also facilitate plant sales in times of adequate and low water periods.
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Wesche, K., M. Pietsch, K. Ronnenberg, R. Undrakh, and I. Hensen. "Germination of fresh and frost-treated seeds from dry Central Asian steppes." Seed Science Research 16, no. 2 (June 2006): 123–36. http://dx.doi.org/10.1079/ssr2006239.
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We tested the germination of fresh and frost-treated seeds of 26 species of southern Mongolian mountain and desert steppes, covering the major growth forms of woody and herbaceous perennials and short-lived species in the region. In the field, germination depends on rains that are largely restricted to the summer months between June and August. Thus, germination tests were performed at alternating conditions of 10°C in darkness and 20°C in light (12 h/12 h), which correspond to temperatures at the study site in early and late summer. Seeds of both woody and herbaceous perennials germinated well under the chosen conditions and apparently did not require stratification or scarification. In contrast, germination of annual species was mostly below 30%, while seed viability was equally high in all three growth forms. Winter conditions, simulated by freezing dried seeds at −18°C, hardly changed seed germination in the perennial species, but several short-lived species responded with increased germination. Short-lived species are not abundant in the real vegetation, which is governed by perennials. Thus, we conclude that the important species in Mongolian mountain steppes germinate readily without a dormancy-breaking treatment. A review of the available literature revealed that a complete lack of dormancy, or presence of only conditional dormancy, is also widely described for other species of Central Asian deserts and steppes, which is in contrast to data from North American prairies.
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Davies, Kirk W., Chad S. Boyd, Jon D. Bates, and April Hulet. "Dormant season grazing may decrease wildfire probability by increasing fuel moisture and reducing fuel amount and continuity." International Journal of Wildland Fire 24, no. 6 (2015): 849. http://dx.doi.org/10.1071/wf14209.
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Mega-fires and unprecedented expenditures on fire suppression over the past decade have resulted in a renewed focus on presuppression management. Dormant season grazing may be a treatment to reduce fuels in rangeland, but its effects have not been evaluated. In the present study, we evaluated the effect of dormant season grazing (winter grazing in this ecosystem) by cattle on fuel characteristics in sagebrush (Artemisia L.) communities at five sites in south-eastern Oregon. Winter grazing reduced herbaceous fuel cover, continuity, height and biomass without increasing exotic annual grass biomass or reducing bunchgrass basal area or production. Fuel moisture in winter-grazed areas was high enough that burning was unlikely until late August; in contrast, fuels in ungrazed areas were dry enough to burn in late June. Fuel biomass on perennial bunchgrasses was decreased by 60% with winter grazing, which may reduce the potential for fire-induced mortality. The cumulative effect of winter grazing from altering multiple fuel characteristics may reduce the likelihood of fire and the potential severity in sagebrush communities with an understorey dominated by herbaceous perennials. Dormant season grazing has the potential to reduce wildfire suppression expenditures in many rangelands where herbaceous fuels are an issue; however, increasing woody vegetation and extreme fire weather may limit its influence.
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Chmielewski, J. G., and J. C. Semple. "The biology of Canadian weeds. 125. Symphyotrichum ericoides (L.) Nesom (Aster ericoides L.) and S. novae-angliae (L.) Nesom (A. novae-angliae L.)." Canadian Journal of Plant Science 83, no. 4 (October 1, 2003): 1017–37. http://dx.doi.org/10.4141/p01-179.
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Symphyotrichum ericoides, the heath aster, is a herbaceous perennial, arising from woody, corm-like rootstocks or herbaceous rhizomes. This facultative upland species occurs in open, dry ground in plains, railway sidings, prairies, ranges, glades, grassy hillsides, dunes, sand bars, river banks, shore salt flats, and thickets. A weed in Canada, and sometimes declared so in the United States and other times not, S. ericoides has an extensive North American distribution, occurring from Nova Scotia and Maine in the east, westward to southern British Columbia, and southward to northern Mexico. No infraspecific taxa are recognized in this treatment of the species. Symphyotrichum novae-angliae, the New England aster, is a herbaceous perennial, arising from thick, short-branched, woody rootstocks. This facultative wetland species occurs in open places such as along roadside ditches and fence rows, on dry ground in plains, prairies and glades, in clearings, meadows and abandoned fields, and along stream banks and swamps, or in moist open or sometimes wooded places. A weed in both Canada and the United States, S. novae-angliae occurs commonly throughout the northern two-thirds of the eastern deciduous forest region of North America and onto the Great Plains. In the east, Nova Scotia populations are likely escaped cultivars, but in the west, isolated natural populations occur from the Black Hills region of South Dakota south to New Mexico. No infraspecific taxa are reco gnized in this treatment of the species. In those habitats where the two species co-occur, the morphologically intermediate F1hybrid S. amethystinum is often found. Key words: Symphyotrichum ericoides, Aster ericoides, Aster multiflorus, heath aster, Symphyotrichum novae-angliae, Aster novae-angliae, New England aster
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Niemiera, Alex X., and Carol E. Leda. "225 SURVEY OF PLANT MATERIALS INSTRUCTORS." HortScience 29, no. 5 (May 1994): 461f—461. http://dx.doi.org/10.21273/hortsci.29.5.461f.
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A survey to determine teaching methodologies for plant material courses was conducted. A total of 120 surveys was sent to horticulture programs at U.S. universities and colleges. Thirty-nine, 22, and 8 respondents taught a woody plant (W), a herbaceous perennial (HP)/annual (A) course, and a foliage plant course, respectively; 21 respondents taught a combination of theses courses. The following similarities were noted for W and HP/A: 1) about 190 species per Semester were presented usually in a taxonomic order using slides as the primary teaching medium for lecture, 2) the most common student complaint was too much work and memorization, 3) the most common student compliment was the practical and useful nature of the subject matter, 4) in order of importance, plant identification, landscape value, and plant cultural aspects were emphasized. For W and HP/A, 93% and 65% of plants, respectively, were presented as landscape and arboreta specimens. Seventy percent of W courses used Dirr's Manual of Woody Landscape Plants; 58% and 10% of HP/A courses used Still's Manual of Herbaceous Ornamental Plants and Taylor's Guides, respectively.
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Yang, Xiaohan, Udaya C. Kalluri, Sara Jawdy, Lee E. Gunter, Tongming Yin, Timothy J. Tschaplinski, David J. Weston, Priya Ranjan, and Gerald A. Tuskan. "The F-Box Gene Family Is Expanded in Herbaceous Annual Plants Relative to Woody Perennial Plants." Plant Physiology 148, no. 3 (September 5, 2008): 1189–200. http://dx.doi.org/10.1104/pp.108.121921.
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Al-Tabini, Raed, Derek W. Bailey, Khalid Al-Khalidi, and Mostafa Shodiafat. "Preferences of sheep, when supplemented, for forages in a Mediterranean rangeland management system." Rangeland Journal 36, no. 1 (2014): 35. http://dx.doi.org/10.1071/rj13082.
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Most rangelands in Jordan are degraded and contain almost no perennial vegetation. A study was conducted near Tal alRumman, Jordan to evaluate grazing behaviour of sheep under typical sheep management conditions where supplemental barley provides the majority of the intake by sheep. The objectives were to determine if sheep preferred herbaceous or woody vegetation and to evaluate a management system that utilises limited areas of ungrazed perennial vegetation in expanses of heavily-grazed and severely-degraded rangeland. Twenty-five Awassi ewes were placed in three 0.1-ha paddocks of ungrazed native rangeland for 2.5 h each day for 3 consecutive days and observed. The three paddocks were grazed for 9 days during each of four seasons: winter, spring, summer and autumn. Sheep were herded to and from the experimental paddocks in the morning and were fed 0.5 kg of barley in the evening. Virtually all grazing occurred in the experimental paddocks because rangeland areas where sheep were housed were severely degraded and contained very little herbage (<40 kg DM ha–1). Herbage mass of herbaceous perennial vegetation in the study area averaged 165 kg DM ha–1 and potentially edible portions (leaves and twigs) of shrubs averaged 82 kg DM ha–1. Sheep spent more time (P < 0.05) grazing than browsing, chewing, standing or ruminating during all seasons. Sheep spent most of their time grazing during the first hour of grazing, and then the time spent grazing declined (P < 0.05) and time standing and ruminating tended to increase near the end of the 2.5-h grazing period. Under typical management in Jordan where sheep are supplemented with barley, sheep clearly preferred herbaceous vegetation over shrubs. To meet sheep preferences, rangeland restoration efforts in Jordan should focus on establishment of mixes of grasses, forbs and shrubs rather than planting only shrubs. This study suggests that allowing sheep access to perennial vegetation for 2–3 h per day can potentially extend the grazing period of limited areas of restored rangeland while providing sheep sufficient time to complete a grazing bout.
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Hily, Jean-Michel, Michel Ravelonandro, Vern Damsteegt, Carole Bassett, Cesar Petri, Zongrang Liu, and Ralph Scorza. "Plum Pox Virus Coat Protein Gene Intron-hairpin-RNA (ihpRNA) Constructs Provide Resistance to Plum Pox Virus in Nicotiana benthamiana and Prunus domestica." Journal of the American Society for Horticultural Science 132, no. 6 (November 2007): 850–58. http://dx.doi.org/10.21273/jashs.132.6.850.
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Constructs with self-complementary sequences separated by an intron produce “hairpin” RNA [intron-hairpin-RNA (ihpRNA)] structures that efficiently elicit posttranscriptional gene silencing (PTGS). In the current study, the authors use this technology to confer resistance to plum pox virus (PPV) in herbaceous and woody perennial plants by silencing the PPV–coat protein (CP) gene. The authors confirmed the high capacity of ihpRNA constructs for inducing RNA silencing in Nicotiana benthamiana Domin., as more than 75% of the transformants displayed PTGS as evaluated by specific small interfering RNA (siRNA) production. The authors demonstrated that ihpRNA constructs provided PPV resistance, and they found a correlation between the length of the PPV sequence introduced in the ihpRNA constructs and the frequency of transgenic-resistant plants. Plants transformed with the full-length sequence produced a higher percentage of resistant lines. The authors further demonstrated for the first time that ihpRNA technology is applicable to a woody perennial species. A transgenic plum (Prunus domestica L.) PPV-CP ihpRNA line showed gene silencing characteristics (hypermethylation of the transgene sequence and specific siRNA production) and resistance to PPV infection 16 months after inoculation.
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Nieman, Tim, Yvonne Hoogzaad, Susara J. E. Marcotte, and Peter Ryser. "Contrasting root overwintering strategies of perennial wetland monocots." Botany 96, no. 10 (October 2018): 653–61. http://dx.doi.org/10.1139/cjb-2018-0065.
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Root turnover is an important contributor to ecosystem nutrient and carbon cycling, but seasonal aspects of root mortality are not well known. This study tests the hypothesis that in strongly seasonal climates, such as in Northern Ontario, Canada, perennial wetland monocots fall into two distinct categories with respect to their root overwintering strategy: complete senescence or survival over the winter. Root survival in late winter and early spring was tested for a total of 26 species using vitality staining with tetrazolium chloride. Root survival in spring was either over 85% (18 species) or 0% (8 species). Lateral root survival was marginally lower than that of basal roots. In some species, low nutrient supply slightly increased root winter mortality, but did not change the seasonal pattern. We conclude that in a northern temperate climate, the overwintering strategies of roots of herbaceous monocots are binary: either avoidance or tolerance of the long unfavourable season, similar to deciduous and evergreen leaves among woody plants. Roots do not gradually die during the unfavourable season, but either completely senesce in the autumn or survive the winter. The distinct root overwintering strategies presumably affect the species’ resource economics and ecosystem processes.
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Hicks, Samantha, and Roy Turkington. "Compensatory growth of three herbaceous perennial species: the effects of clipping and nutrient availability." Canadian Journal of Botany 78, no. 6 (June 1, 2000): 759–67. http://dx.doi.org/10.1139/b00-051.
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The continuum of responses model (CRM) and the growth rate model (GRM) make conflicting predictions about the effects of soil nutrient availability on the resilience of plants to herbivory. A factorial experiment was conducted in the understory of the boreal forest to examine the effects of fertilization and simulated herbivory on the rate and amount of regrowth of three herbaceous perennial species (Achillea millefolium L., Festuca altaica Trin., and Mertensia paniculata (Aiton) G. Don.). As clipping intensity increases various measures of plant performance decrease. Fertilization reduces the ability of clipped plants to compensate for biomass loss regardless of species and growth measure. Under natural soil fertility levels in this study, M. paniculata is more likely to compensate for leaf loss than A. millefolium and F. altaica. Contrary to the findings of previous field studies, the compensatory responses of the three species studied were most consistent with the predictions of the GRM. Plants in our study sites grow in nutrient-poor soils, whereas the majority of compensatory studies have been carried out on herbaceous or woody plants in temperate regions. Resources are generally more abundant in temperate zones than in boreal forest zones, and the GRM may be a better predictor of compensatory ability of plants growing in naturally nutrient-deficient soils.Key words: herbivory, regrowth, fertility level, clipping intensity, compensation.
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Carlquist, Sherwin. "Wood and Bark Anatomy of Aristolochiaceae; Systematic and Habital Correlations." IAWA Journal 14, no. 4 (1993): 341–57. http://dx.doi.org/10.1163/22941932-90000588.
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Wood of Aristolochiaceae has vessels with simple petforation plates; lateral wall pitting of vessels alternate to scalariform; tracheids, fibre-tracheids or libriform fibres present; axial parenchyma diffuse, diffuse-in-aggregates, scanty vasicentric, and banded apotracheal; rays wide and tall, paedomorphic, multiseriate only, little altered during ontogeny (new rays originate suddenly as wid~ multiseriate rays); ethereal oil cells present in rays; wood structure storied. All of these features occur in Lactoridaceae and Piperaceae, and support the grouping of Aristolochiaceae with these families and the nonwoody family Saururaceae. Chloranthaceae may be the family next closest to this assemblage. Druses characteristically occur in rays of Aristolochia. Tracheids in Aristolochia may be correlated with the lianoid habit, although Holostylis, a caudex perennial thought close to Aristolochia, also has tracheids. The fibre-tracheids and libriform fibres of Apama and Thottea may be related to the sympodial shrubby habit of those two genera. On the basis of one species each of Apama and Thottea, the genera differ with respect to wood anatomy. The paedomorphic ray structure of all genera of Aristolochiaceae suggests an herbaceous or minimally woody ancestry rather than ancestors with typically woody monopodial habit. Types of bark structure observed in the species surveyed are briefly characterised. Storied wood structure and presence of druses and ethereal oil cells in rays are newly reported for the family.
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McCown, Brent H. "Special symposium: In vitro plant recalcitrance recalcitrance of woody and herbaceous perennial plants: Dealing with genetic predeterminism." In Vitro Cellular & Developmental Biology - Plant 36, no. 3 (May 2000): 149–54. http://dx.doi.org/10.1007/s11627-000-0030-6.
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Young, Kert R., Bruce A. Roundy, Stephen C. Bunting, and Dennis L. Eggett. "Utah juniper and two-needle piñon reduction alters fuel loads." International Journal of Wildland Fire 24, no. 2 (2015): 236. http://dx.doi.org/10.1071/wf13163.
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Juniper (Juniperus spp.) and piñon (Pinus spp.) trees have encroached millions of hectares of sagebrush (Artemisia spp.)–bunchgrass communities. Juniper–piñon trees are treated to reduce canopy fuel loads and crown fire potential. We measured the effects of juniper–piñon infilling and fuel-reduction treatments on fuel load characteristics at four locations in Utah. At each location, treatment areas were burned, left untreated, or trees were cut or masticated in a randomised complete-block design. We measured standing and downed fuels by size and type along 30-m transects on 15 subplots (30 × 33 m) per location before and 1–3 years after treatment. Increased tree cover was associated with decreased shrub and herbaceous fuel loads (P < 0.01). By 2 years post-treatment, herbaceous fuel loads were greater than pretreatment in all treated areas (P < 0.01). Cut and mastication treatments increased surface woody 10- and 100-h fuel loads and wood/bark cover (P < 0.01). Masticated-tree depth was a good estimator of fuel loads (R2 = 92). The conversion of canopy fuels to surface fuels reduced fuels that enable crown fire and extreme fire intensity. Cool-season prescribed fire may need to follow mechanical treatments to reduce surface fuel and the potential for wildfire damage to perennial understorey vegetation.
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White, Scott N., Nathan S. Boyd, and Rene C. Van Acker. "Evaluation of aminocyclopyrachlor applied aloneand in combination with registered herbicides for crop tolerance and weed control in wild blueberry (Vaccinium angustifolium Ait.)." Canadian Journal of Plant Science 96, no. 1 (February 1, 2016): 11–16. http://dx.doi.org/10.1139/cjps-2015-0214.
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The pyrimidine herbicide aminocyclopyrachlor was evaluated for crop tolerance and weed control in wild blueberry (Vaccinium angustifolium Aiton). Preemergence applications of aminocyclopyrachlor at a rate of 50 g a.i. ha−1 did not reduce aboveground blueberry biomass, yield potential, or final yield, and this rate appears safe for use in wild blueberry. Preemergence applications of aminocyclopyrachlor at a rate of 100 g a.i. ha−1 reduced aboveground blueberry biomass, but yield potential and final yield were only reduced significantly at application rates of 200 and 400 g a.i. ha−1. Preemergence applications of aminocyclopyrachlor at a rate of 100 g a.i. ha−1 effectively suppressed Euthamia graminifolia (L.) Nutt., and further evaluation of aminocyclopyrachlor to identify safe application timings and rates in wild blueberry is warranted. Aminocyclopyrachlor applied as a directed spot spray provided good control of several herbaceous and woody perennial weeds, and this use pattern could provide an alternative management option for many perennial weeds in wild blueberry.
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Clarke, Peter J., Elizabeth A. Davison, and Lindsay Fulloon. "Germination and dormancy of grassy woodland and forest species: effects of smoke, heat, darkness and cold." Australian Journal of Botany 48, no. 6 (2000): 687. http://dx.doi.org/10.1071/bt99077.
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The germination requirements of a broad spectrum of common species found in grassy woodlands and forests in the New England region of northern New South Wales were tested in a series of replicated growth-cabinet experiments. The effects of dark/diurnal light and smoke/no smoke were measured on 65 species in an orthogonal experiment, 21 of which were retested after storage for 12 months. The effect of storage for several years was also assessed under a diurnal light regime. In addition, the effects of preimbibition heat (80˚C), and chilling on germination were also measured. A single temperature regime (15˚C night/25˚C day) was used in all treatments for comparative purposes. Most species had high viability and germinability under a diurnal light regime. Small shrub species included, however, a large proportion of species with entrenched dormancy. Light enhanced germination of 21 species significantly, whereas dark stimulated germination of only eight species. Heat and cold treatments also stimulated some germination but more often inhibited germination or produced no effect. Smoke stimulated germination, relative to other cues, in only one species (Ajuga australis) and more often inhibited germination or produced no effect. The relationship between variation in germination (stimulation, no effect or inhibition) of species in six growth-form classes was tested by using contingency tables for each treatment. No significant relationship between growth form and the effects of light, smoke or chilling was detected. Preimbibition heat effects were, however, significantly different among growth forms. Subshrubs showed a higher than expected proportion of species with a heat stimuli while herbaceous species showed a higher than expected proportion of species inhibited by preimbibition heat. Germinability generally increased in herbaceous species when stored at ambient temperatures while it remained relatively constant in woody species. Conversely, viability decreased in herbaceous species but remained relatively more constant in woody species. The effects of seed storage and high germinability suggest that most perennial herbaceous species have transient or short-term persistent seed banks. Germinability, with and without cues, was also negatively correlated with increasing seed size and larger growth forms. These traits might be related to the need for woody species, with soil-stored seed banks, to spread establishment risks in an environment where herbaceous competition and herbivory are likely to be important selection factors.
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G. J. Sultangazina, А. N. Kuprijanov, О. А. Kuprijanov, and R. S. Beyshov. "COENOFLORA OF ADONIS VERNALIS L. IN NORTHERN KAZAKHSTAN." BULLETIN 1, no. 383 (February 15, 2020): 33–41. http://dx.doi.org/10.32014/2020.2518-1467.4.
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The current article presents the results of the study made on Adonis vernalis L. coenoflora of Northern Kazakhstan. The materials have been obtained in the course of field research considering the literary data. The list of Adonis vernalis L. flora discovered in Northern Kazakhstan is based on detailed route studies. The coenoflora of Adonis vernalis L. in Northern Kazakhstan includes 140 species belonging to 31 families and 96 genera. The leading families are Artemisia, Veronica, Achillea, Galatella, Lathyrus, Potentilla, Seseli, Silene. The majority of species belongs to perennial species, annuals and biennials are represented by six species, and there is only one ephemeral species. Woody and semi-woody plants are represented by three trees, five shrubs and one semishrub. Among the herbaceous plants there are more long-rooted and stem-rooted species. The coenoflora mainly consists of mesophytes (68 species) and xeromesophytes (57 species). There are 15 species of xerophytes, which makes 10,7%. A little number of xerophytes proves meadow and meadow-steppe nature of the coenoflora.
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Tadesse, Eguale, Abdu Abdulkedir, Asia Khamzina, Yowhan Son, and Florent Noulèkoun. "Contrasting Species Diversity and Values in Home Gardens and Traditional Parkland Agroforestry Systems in Ethiopian Sub-Humid Lowlands." Forests 10, no. 3 (March 15, 2019): 266. http://dx.doi.org/10.3390/f10030266.
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Understanding the complex diversity of species and their potential uses in traditional agroforestry systems is crucial for enhancing the productivity of tropical systems and ensuring the sustainability of the natural resource base. The aim of this study is the evaluation of the role of home gardens and parklands, which are prominent tropical agroforestry systems, in the conservation and management of biodiversity. Our study quantified and compared the diversity of woody and herbaceous perennial species and their uses in traditional home gardens and parkland agroforestry systems under a sub-humid climate in western Ethiopia. A sociological survey of 130 household respondents revealed 14 different uses of the species, mostly for shade, fuelwood, food, and as traditional medicine. Vegetation inventory showed that the Fisher’s α diversity index and species richness were significantly higher in home gardens (Fisher’s α = 5.28 ± 0.35) than in parklands (Fisher’s α = 1.62 ± 0.18). Both systems were significantly different in species composition (Sørenson’s similarity coefficient = 35%). The differences occurred primarily because of the high intensity of management and the cultivation of exotic tree species in the home gardens, whereas parklands harbored mostly native flora owing to the deliberate retention and assisted regeneration by farmers. In home gardens, Mangifera indica L. was the most important woody species, followed by Cordia africana Lam. and Coffea arabica L. On the other hand, Syzygium guineense Wall. was the most important species in parklands, followed by C. africana and M. indica. The species diversity of agroforestry practices must be further augmented with both indigenous and useful, non-invasive exotic woody and herbaceous species, particularly in parklands that showed lower than expected species diversity compared to home-gardens.
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Zheng, Tangchun, Lijuan Dai, Yi Liu, Shuang Li, Mi Zheng, Zhongnan Zhao, and Guan-Zheng Qu. "Overexpression Populus d-Type Cyclin Gene PsnCYCD1;1 Influences Cell Division and Produces Curved Leaf in Arabidopsis thaliana." International Journal of Molecular Sciences 22, no. 11 (May 29, 2021): 5837. http://dx.doi.org/10.3390/ijms22115837.
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d-type cyclins (CYCDs) are a special class of cyclins and play extremely important roles in plant growth and development. In the plant kingdom, most of the existing studies on CYCDs have been done on herbaceous plants, with few on perennial woody plants. Here, we identified a Populus d-type cyclin gene, PsnCYCD1;1, which is mainly transcribed in leaf buds and stems. The promoter of PsnCYCD1;1 activated GUS gene expression and transgenic Arabidopsis lines were strongly GUS stained in whole seedlings and mature anthers. Moreover, subcellular localization analysis showed the fluorescence signal of PsnCYCD1;1-GFP fusion protein is present in the nucleus. Furthermore, overexpression of the PsnCYCD1;1 gene in Arabidopsis can promote cell division and lead to small cell generation and cytokinin response, resulting in curved leaves and twisted inflorescence stems. Moreover, the transcriptional levels of endogenous genes, such as ASs, KNATs, EXP10, and PHB, were upregulated by PsnCYCD1;1. Together, our results indicated that PsnCYCD1;1 participates in cell division by cytokinin response, providing new information on controlling plant architecture in woody plants.
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Li, Ai, Bao-Quan Hu, Zhen-Yi Xue, Li Chen, Wei-Xing Wang, Wen-Qin Song, Cheng-Bin Chen, and Chun-Guo Wang. "DNA Methylation in Genomes of Several Annual Herbaceous and Woody Perennial Plants of Varying Ploidy as Detected by MSAP." Plant Molecular Biology Reporter 29, no. 4 (January 13, 2011): 784–93. http://dx.doi.org/10.1007/s11105-010-0280-3.
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Kraus, Helen T., Stuart L. Warren, and Charles E. Anderson. "Nitrogen Form Affects Growth, Mineral Nutrient Content, and Root Anatomy of Cotoneaster and Rudbeckia." HortScience 37, no. 1 (February 2002): 126–29. http://dx.doi.org/10.21273/hortsci.37.1.126.
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Five ratios of NH4+: NO3-(100:0, 75:25, 50:50, 25:75, and 0:100) were evaluated for impact on growth of Cotoneaster dammeri Schneid. `Skogholm' (cotoneaster), a woody ornamental shrub, and Rudbeckia fulgida Ait. `Goldsturm' (rudbeckia), an herbaceous perennial. Nitrate alone decreased dry weight and leaf area of cotoneaster and rudbeckia compared with mixtures of NH4+ and NO3- and NH4+ alone. Additionally, NO3- alone suppressed accumulation of cationic nutrients and N in cotoneaster, while mixes of NH4+ and NO3- enhanced accumulation of nutrients in roots and shoots of rudbeckia compared with solutions containing either NH4+ or NO3- alone. The steles of roots of cotoneaster and rudbeckia contained more secondary xylem with larger tracheary elements with a mix of 25 NH4+: 75 NO3- than with NO3- alone.
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Pillitteri, Lynn Jo, Carol J. Lovatt, and Linda L. Walling. "Isolation and Characterization of LEAFY and APETALA1 Homologues from Citrus sinensis L. Osbeck `Washington'." Journal of the American Society for Horticultural Science 129, no. 6 (November 2004): 846–56. http://dx.doi.org/10.21273/jashs.129.6.0846.
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Homologues of the floral meristem identity genes LEAFY (LFY) and APETALA1 (AP1) were isolated from the hybrid perennial tree crop `Washington' navel orange (Citrus sinensis) and designated CsLFY and CsAP1, respectively. Citrus has an extended juvenile period unlike herbaceous plants and responds to different floral stimuli than herbaceous plants or deciduous tree species. Despite these differences, the deduced amino acid sequences of CsLFY and CsAP1 genes are at least 65% identical with their Arabidopsis thaliana L. Heynh counterparts and share even greater sequence similarity to LFY and AP1 from the deciduous woody perennials, Populus balsamifera Bradshaw and Populus tremuloides Michaux, respectively. Like A. thaliana LFY (AtLFY) and AP1 (AtAP1), CsLFY and CsAP1 expression was restricted almost exclusively to reproductive tissues, but observed expression of CsAP1 in the fourth whorl carpel tissue of mature flowers was distinct from other plant AP1 genes. Transgenic A. thaliana plants ectopically expressing CsLFY or CsAP1 showed early-flowering phenotypes similar to those described for overexpression of AtLFY and AtAP1. In addition, the 35S:CsLFY and 35S:CsAP1 transgenes partially complemented the lfy-10 and ap1-3 mutants, respectively. The severity of the overexpression phenotypes correlated with the accumulation of CsLFY or CsAP1 transcripts. LFY is a single-copy gene in flowering plants but consistent with its hybrid origin, the genome of C. sinensis `Washington' has two easily distinguishable CsLFY and CsAP1 alleles derived from it's parental genotypes, C. maxima L. Osbeck (pummelo) and C. reticulata Blanco (mandarin). Allelic polymorphism at both the CsLFY and CsAP1 loci was restricted to the 5′- and 3′-flanking regions.
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Boutin, Céline, Benoît Jobin, Luc Bélanger, and Line Choinière. "Comparing weed composition in natural and planted hedgerows and in herbaceous field margins adjacent to crop fields." Canadian Journal of Plant Science 81, no. 2 (April 1, 2001): 313–24. http://dx.doi.org/10.4141/p00-048.
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Hedgerows and field margins are common features of the agricultural landscape in southern Québec. In the last decade, hedgerow establishment has been encouraged primarily for the prevention of soil erosion, though many farmers view them as reservoirs of invasive weeds and pests. In this study, we compared weed assemblages of several hedgerow types and herbaceous field margins. Ranking that takes into consideration weed abundance was clearly demonstrated: planted hedgerows > herbaceous field margins > natural woody hedgerows. The latter harboured many perennial plant species of less weedy propensity than planted hedgerows, which accommodated a larger number of weedy species. In planted hedgerows close to 50% of plants were weeds, even in their central position, although planted and natural hedgerows sheltered similar weed composition in their central parts. Likewise, most species inventoried in adjacent fields were weeds. Weeds characterising the central position of hedgerows/field margins were often species of wet habitats (Lythrum salicaria L., Equisetum arvense L., Cicuta maculata L.). Management practices of hedgerows and perhaps of crop fields adjacent to hedgerows may be mostly responsible for the abundance of weeds in hedgerows and field margins. Key words: Hedgerow, field margins, weed, management practices, pesticide, fertiliser
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McIntyre, S., T. G. Martin, K. M. Heard, and J. Kinloch. "Plant traits predict impact of invading species: an analysis of herbaceous vegetation in the subtropics." Australian Journal of Botany 53, no. 8 (2005): 757. http://dx.doi.org/10.1071/bt05088.
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The need to predict potential invasion impact of plant species is important for setting weed-management priorities and determining quarantine restrictions for newly imported plant material. We analysed the naturalised plant component of a herbaceous plant community in sub-tropical eucalypt woodlands subjected to various disturbances associated with agricultural activities. The native and naturalised plant species did not differ in the proportions of different life forms, although life-history differed, with the naturalised group having more annual and biennial, and relatively fewer perennial species. We classified the naturalised assemblage into high- and low-impact species and compared the plant-trait and habitat characteristics of the two groups. Low-impact species covered a range of levels of habitat specialisation whereas high-impact species tended to have moderate to low levels of specialisation and to be less tolerant of grazing. Seven traits were found to be significantly associated with impact. Stepwise regression indicated a high level of redundancy in the data, owing to attributes being correlated. For all species, four attributes were significant in determining impact: very wide lateral spread, C4 photosynthesis, tall height and large leaves. For forbs, only two attributes (large seeds, adhesion/ingestion mode of seed dispersal) were significant in the overall model. We identified the following eight functional types amongst the naturalised species: (i) high-impact C4 lawn grasses, (ii) high-impact C4 bulky tussock grasses, (iii) moderate-impact annual grasses, (iv) moderate-impact tall annual forbs, (v) moderate-impact spreading forbs, (vi) moderate-impact woody forbs, (vii) low-impact legumes and (viii) low-impact small ruderals. In the subtropical woodland environment perennial C4 grasses appear to present the greatest invasive threat to herbaceous native communities, whereas forbs of wide lateral spread, with large animal-dispersed seeds are also problematic. The results support a case for limiting further importation of horticultural and forage material into Australia.
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Zelnik, Igor, Valentina Mavrič Klenovšek, and Alenka Gaberščik. "Complex Undisturbed Riparian Zones Are Resistant to Colonisation by Invasive Alien Plant Species." Water 12, no. 2 (January 25, 2020): 345. http://dx.doi.org/10.3390/w12020345.
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We investigated the presence and abundance of invasive alien plant species (IAS) in the riparian zones of rivers in relation to different environmental parameters. We surveyed the spatial and human-influenced characteristics of the riparian zones, river channels, and land use along seven Slovenian rivers. We further monitored the presence and abundance of IAS with different natural properties and different human impacts to define the characteristics of non-infected and heavily infected reaches. Special attention was given to different life forms of IAS. The presence and abundance of IAS positively correlated with distance from river source, current velocity, and water depth, and negatively correlated with altitude, naturalness of the land use, width and completeness of the riparian zone, height and structure of its vegetation, and condition of the riverbed and banks. Annuals prevailed among IAS at 48%, with 37% herbaceous perennials and 15% woody species. The vine Echinocystis lobata was the most abundant IAS, which was found in 179 out of the 414 river reaches analysed, followed by the annual Impatiens glandulifera and the herbaceous perennial Solidago gigantea. E. lobata was spread over the native riparian vegetation and was affected by the natural gradients of the rivers in terms of altitude and distance from the river’s source. Reaches without IAS significantly differed from reaches colonised with IAS in the width of riparian zone, vegetation height and structure, land-use next to the river, and distance from the source. As IAS in riparian zones affect riparian and aquatic communities, there is the need for management practices to maintain and establish complex riparian zones that are resistant to IAS colonisation.
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Weir, B. J., R. G. St. Pierre, and R. N. Chibbar. "Isolation of DNA for RAPD analysis from leaves of the saskatoon (Amelanchier alnifolia Nutt.) and other horticultural crops." Canadian Journal of Plant Science 76, no. 4 (October 1, 1996): 819–24. http://dx.doi.org/10.4141/cjps96-139.
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Three DNA extraction procedures were examined to determine which might yield DNA from saskatoon leaves suitable for randomly amplified polymorphic DNA (RAPD) analysis. The three methods examined were: (1) the miniprep procedure and (2) the modified miniprep for difficult species, both described by Dellaporta et al. (1983), and (3) a slightly modified protocol of Doyle and Doyle (1990). Only the modified method of Doyle and Doyle (1990) consistently yielded DNA suitable for polymerase chain reaction (PCR) amplification, regardless of plant growing conditions or leaf age. The recovery of high molecular weight DNA with an average yield of 53 mg g−1 fresh weight of leaf material was possible using this procedure. Reproducible RAPD markers used to distinguish among saskatoon cultivars were generated. This same procedure also yielded PCR-amplifiable DNA from various other perennial, woody species and herbaceous plant material. Key words: DNA isolation; RAPD analysis; horticultural crops.
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Lakshminarayana, G., and A. J. Solomon Raju. "Pollination ecology of Merremia tridentata (L.) Hallier f. (Convolvulaceae)." Journal of Threatened Taxa 10, no. 2 (February 26, 2018): 11339. http://dx.doi.org/10.11609/jott.3252.10.2.11339-11347.
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Merremia tridentata is a twining and prostrate herb. The flowers are campanulate, bisexual, weakly protandrous, self-compatible and facultative autogamous. The forager guilds indicate that thripsophily, melittophily and psychophily are functional pollination syndromes. Ballistichory, anemochory and hydrochory are the seed dispersal modes. Seeds germinate as soon as they reach the ground if the soil has sufficient moisture or else they remain dormant and germinate during the rainy season. Such seed dispersal modes and flexible germination responses enable the plant to invade and colonize new areas. Further, the plant with perennial woody root stock stays alive during the dry season, sprouts back to life during the rainy season to re-start its life cycle. The dual modes of regeneration enable the plant to form extensive herbaceous cover and bind the soil effectively. Therefore, the plant is an important soil binder and useful at controlling soil erosion.
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Babkova, A. S. "BUILDING UP THE COLLECTION HOLDINGS OF PERENNIAL ORNAMENTAL PLANTS FROM THE FAMILY ROSACEAE AT THE POLAR EXPERIMENT STATION OF VIR." VAVILOVIA 2, no. 1 (August 8, 2019): 57–62. http://dx.doi.org/10.30901/2658-3860-2019-1-57-62.
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The article discusses the prospects of building up a collection of ornamental plants belonging to the rose family (Rosaceae Juss.) from local cultivated and wild plant forms in order to expand the zonal assortment of ornamentals for urban landscape gardening in Murmansk Province. Since 2017, the Polar Experiment Station of the Vavilov Institute (VIR) has been engaged in systematic research activities aimed at introduction of ornamental perennial ornamental herbs and shrubs. A promising collection stock has been formed of ornamental plants, currently totaling 198 accessions (160 species) from 40 plant families, including 132 accessions of perennial herbaceous plants (77 genera), 58 of ornamental shrubs (10 genera), and 8 of woody plants (4 genera). Representatives of the family Rosaceae make up 25% of the total number of accessions. The Polar Experiment Station maintains wild and cultivated perennial plants of the genera Geum L., Filipendula L., Potentilla L., Sanguisorba L., Alchimilla L., Dryas L., Spiraea L., Rosa L., Sorbus L., Dasifora Rafin., etc., having ornamental qualities, characterized by high winter hardiness, and not requiring high expenditures for their maintenance. Further expansion of the Rosaceae collection is going to be based on the introduction of ornamentals from the rose family identified in the local vegetation of the Kola Peninsula as well as through the acquisition of accessions from botanical gardens and nurseries located in the areas with climate conditions close to those of the Polar Experiment Station of VIR.
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Cupido, C. N., W. M. M. Eddie, and L. R. Tiedt. "SYSTEMATIC AND ECOLOGICAL SIGNIFICANCE OF SEED COAT MORPHOLOGY IN SOUTH AFRICAN CAMPANULACEAE SENSU STRICTO." Edinburgh Journal of Botany 68, no. 3 (October 18, 2011): 351–71. http://dx.doi.org/10.1017/s0960428611000291.
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The seed coat morphology of 50 species of Campanulaceae sensu stricto, representing all 10 South African genera, was studied by scanning electron microscopy to gauge its usefulness in the diagnosis of genera or to support clades. Possible correlations with life form (annual, herbaceous and woody perennial) and ecological requirements such as fire response, rainfall requirements, bedrock and soil preferences, as well as habitat (e.g. fynbos, strandveld, renosterveld, grassland and karoo), were also investigated. Patterns of variation are described and interpreted as conforming to two seed coat types: reticulate (Type 1) and striate/wavy (Type 2). Type 1 seeds are further divided into eight subtypes. Some general trends emerged; for example, Type 1 seeds occur in all major clades of wahlenbergioids, Type 1A with a smooth coarsely reticulate surface being predominant in fynbos taxa, all of which are woody perennials. Several of the Type 1 seeds, together with Type 2 seeds, also occur in species with wider ecological amplitude, for example in karoo, strandveld or montane grasslands. In Siphocodon there is remarkable disparity in seed type between species. These variations in seed type generally appear to accord with current knowledge of climatic changes and soil evolution during the Tertiary of South Africa, and may be useful indicators of generic emergence and mosaic speciation in the major lineages of wahlenbergioids. However, it was concluded that seed coat types do not correlate closely enough with specific ecological requirements or life forms to be of unequivocal predictive value. Also, apart from Merciera and Treichelia, they are of limited use as a diagnostic character for genera, but are useful for distinguishing species.
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Booth, CA, F. Sanchez-Bayo, and GW King. "Establishment of Woody Weeds in Western New South Wales. 2. Growth and Competitive Potential." Rangeland Journal 18, no. 1 (1996): 80. http://dx.doi.org/10.1071/rj9960080.
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Growth and survival of hopbush (Dodonaea attenuata), turpentine (Eremophila sturtii) and punty bushes (Cassia eremophila and C. artemisioides) were studied in relation to the effects of grazing and shrub density, at four sites in the Bourke-Wanaaring region of western New South Wales during 1979 to 1982. Hopbush shrubs grew faster than turpentine and punty bushes. Small hopbush grew better on open areas, while mature shrubs grew better in dense stands. Turpentine showed better performance in open areas, and punty bush growth was unaffected by shrub population density. All these species showed a high survival rate, particularly in height classes greater than 25 cm, and they kept growing even during drought periods. The effects of grazing on survival were inconclusive. Hopbush and turpentine root development was rapid, attaining depths of over 1.1 m in wet soils, 14 weeks after germination. Mature plants in the field, both hopbush and turpentine, were observed to have extensive lateral root networks at either 22 cm or 30-70 cm soil depth respectively, as well as a tap root system. The characteristics of both species help explain the competitive advantage of these shrubs over herbaceous species, and their survival capability in times of drought. Competition of hopbush with the perennial grass woollybutt (Eragrostis eriopoda) and annual herbage was also examined. In spring, survival of hopbush seedlings was favoured within woollybutt tussocks, this situation being reversed in autumn. Woollybutt biomass was negatively affected by the proximity of hopbush shrubs. Annual herbage seemed not to have any effect on hopbush survival, although shrub seedlings grew better under conditions of moderate herbage cover. Microtopography affected the establishment of both grasses and shrubs, with depressions favouring the growth of grasses at the expense of shrubs during periods of adequate moisture, and the growth of shrubs during drier times. The findings suggest that the woody weed problem is unlikely to wax and wane and that turpentine may be particularly difficult to control. Maintenance of high levels of pasture cover from perennial grasses and annuals may slow down recruitment and growth in open areas with scattered parent shrubs, where control will be less costly, and may contain future spread.
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Staats, David, and James E. Klett. "Evaluation of Weed Control and Phytotoxicity of Preemergence Herbicides Applied to Container-grown Herbaceous and Woody Plants." Journal of Environmental Horticulture 11, no. 2 (June 1, 1993): 78–81. http://dx.doi.org/10.24266/0738-2898-11.2.78.
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Abstract Six different preemergence herbicides were used with eight different plant species to evaluate weed control efficacy and possible phytotoxicity. The species used were Stachys byzantina C. Koch (lamb's ears), Campanula persicifolia L. (peachleaf bellflower), Achillea millefolium L. ‘Summer Pastel’ (common yarrow), Coreopsis lanceolata L. (Lance coreopsis), Gypsophila pacifica Kom. (baby's breath), Wisteria sinensis Sims (Chinese wisteria), Syringa vulgaris L. (common lilac), Phlox paniculata L. (perennial phlox), Dahlia Cav. x hybrida (garden dahlia). Herbicides were applied to the soil surface at rates of lx and 2x as recommended by the label. The herbicides and rates were as follows: Pennant (Dual) 7.8 Liquid, 4.6, 9.1 kg ai/ha (4, 8 lb ai/A); Gallery 75DF, 1.1, 2.3 kg ai/ha (1, 2 lb ai/A); Ronstar 2G, 4.5, 9.0 kg ai/ha (4, 8 lb ai/A); Rout 3G, 3.4, 6.8, 13.6 kg ai/ha (3, 6, 12 lb ai/A); Surflan AS, 2.3, 4.6 kg ai/ha (2, 4 lb ai/A); and Treflan 5G, 4.5, 9.0 kg ai/ha (4, 8 lbs ai/A). Weed seeds of Setaria glauca (L.) Beauv. (yellow foxtail), Echinochloa crus-galli (L.) Beauv. (barnyardgrass), Poa annua L. (annual bluegrass), Capsella bursa-pastoris (L.) Medik. (shepherdspurse), Senecio vulgaris L. (common groundsel), and Amaranthus retroflexus L. (redroot pigweed) were sown on the soil surface. Two control treatments (no herbicide and no weed seeds applied, or no herbicide but with weed seeds) also were evaluated. Plants were grown in #1 black plastic containers in a medium of clay loam soil, plaster sand and sphagnum peat (1:1:2 by vol). Weed counts at the end of the season indicated that weed control was variable according to the herbicide used. Rout and Ronstar at both the lx and 2x rates controlled over 99% of the weeds (compared to the control treatment with weeds). Weed control for the other herbicides were as follows: Surflan lx = 92%, Surflan 2x = 95%, Pennant lx = 93%, Pennant 2x = 98%, Gallery lx = 35%, Gallery 2x = 43%, Treflan 1x = 88%, and Treflan 2x = 96%. Evaluations also indicated that herbicides utilizing oryzalin resulted in phytoxicity or stunting to Phlox (appearance declined 88% at the 1x rate and 93% at the 2x rate compared to the control treatment), Gypsophila (dry weights for Surflan 1x was 27% less and Surflan 2x was 39% less compared to the control treatment), and Stachys (appearance declined 55% for 1x rate and 60% at the 2x rate). Gallery (isoxaben) resulted in stunting in Stachys (dry weights for Gallery 1x were 75% less compared to control plants and Gallery 2x was 80% less).
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Hodgkinson, KC, JW Terpstra, and WJ Muller. "Spatial and Temporal Pattern in the Grazing of Grasses by Sheep Within a Semi-Arid Wooded Landscape." Rangeland Journal 17, no. 2 (1995): 154. http://dx.doi.org/10.1071/rj9950154.
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Grazing the woodlands of semi-arid and arid Australia by domestic stock has extensively collapsed perennial *grass populations and thereby fostered woody plant increase. This study examined the pattern of grazing of individual grass plants by sheep in the landscape of a semi-arid woodland, and a model was developed describing the spatial and temporal influences on the grazing pressure placed on plants. Plants of two widespread perennial grass species differing in palatability, Eragrostis eriopoda and Thyridolepis mitchelliana, were examined weekly in two contrasting periods at the CSIRO Lake Mere Research Facility. The plants were located throughout the landscape in lightly- and heavily- stocked paddocks. Patterns of grazing in space and time were determined by examining the grazing of marked tillers. No preference was shown for previously ungrazed plants and only occasionally were previously grazed plants preferred. Thyridolepis mitchelliana plants were slightly preferred over E. eriopoda plants. Landscape zones receiving water and nutrients from elsewhere were preferred for grazing but the effect was weak. The foliage biomass of herbaceous plants in the immediate vicinity of a grass plant did not influence the number of tillers grazed nor the probability of the plant being grazed. Overall the defoliation of individual plants by sheep was weakly determined by landscape location, stocking level, plant species and prevailing forage on offer. The influence of spatial and temporal variation was small; random grazing of grass plants was the rule. This finding suggests that the grazing pressure on palatable perennial grasses in the paddocks of semi-arid woodlands will be similar across wooded landscapes and that spatial variability in plant mortality could be due to. the combined effect of plant water stress, which varies spatially and temporally, and grazing pressure which varies temporally but not spatially.
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Moreno-de las Heras, M., R. Diaz-Sierra, L. Turnbull, and J. Wainwright. "Assessing vegetation structure and ANPP dynamics in a grassland-shrubland Chihuahuan ecotone using NDVI-rainfall relationships." Biogeosciences Discussions 12, no. 1 (January 6, 2015): 51–92. http://dx.doi.org/10.5194/bgd-12-51-2015.
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Abstract. Climate change and the widespread alteration of natural habitats are major drivers of vegetation change in drylands. A classic case of vegetation change is the shrub-encroachment process that has been taking place over the last 150 years in the Chihuahuan Desert, where large areas of grasslands dominated by perennial grass species (black grama, Bouteloua eriopoda, and blue grama, B. gracilis) have transitioned to shrublands dominated by woody species (creosotebush, Larrea tridentata, and mesquite, Prosopis glandulosa), accompanied by accelerated water and wind erosion. Multiple mechanisms drive the shrub-encroachment process, including exogenous triggering factors such as precipitation variations and land-use change, and endogenous amplifying mechanisms brought about by soil erosion-vegetation feedbacks. In this study, simulations of plant biomass dynamics with a simple modelling framework indicate that herbaceous (grasses and forbs) and shrub vegetation in drylands have different responses to antecedent precipitation due to functional differences in plant growth and water-use patterns, and therefore shrub encroachment may be reflected in the analysis of landscape-scale vegetation–rainfall relationships. We analyze the structure and dynamics of vegetation at an 18 km2 grassland-shrubland ecotone in the northern edge of the Chihuahuan Desert (McKenzie Flats, Sevilleta National Wildlife Refuge, NM, USA) by investigating the relationship between decade-scale (2000–2013) records of medium-resolution remote sensing of vegetation greenness (MODIS NDVI) and precipitation. Spatial evaluation of NDVI-rainfall relationship at the studied ecotone indicates that herbaceous vegetation shows quick growth pulses associated with short-term (previous 2 months) precipitation, while shrubs show a slow response to medium-term (previous 5 months) precipitation. We use these relationships to (a) classify landscape types as a function of the spatial distribution of dominant vegetation, and to (b) decompose the NDVI signal into partial primary production components for herbaceous vegetation and shrubs across the study site. We further apply remote-sensed annual net primary production (ANPP) estimations and landscape type classification to explore the influence of inter-annual variations in seasonal precipitation on the production of herbaceous and shrub vegetation. Our results suggest that changes in the amount and temporal pattern of precipitation comprising reductions in monsoonal summer rainfall and/or increases in winter precipitation may enhance the shrub-encroachment process in desert grasslands of the American Southwest.
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Seri, Hicham, Mohsen Chammem, Severiano Silva, Miguel Rodrigues, Touhami Khorchani, and Luis Ferreira. "Assessment of diet composition of free-ranging addax antelopes (Addaxnasomaculatus) by the combination of microhistological procedures andn-alkanes and long-chain alcohols as fecal markers." Canadian Journal of Zoology 96, no. 11 (November 2018): 1284–89. http://dx.doi.org/10.1139/cjz-2017-0320.
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Understanding herbivore foraging behaviour is crucial for adequate wildlife management decisions. This study assessed the diet composition of free-ranging addax antelope (Addax nasomaculatus (de Blainville, 1816)). Samples collected during the spring season were analyzed using microhistological procedures along with n-alkanes and long-chain alcohols as fecal markers. Twelve animals were monitored and fresh fecal samples were collected daily during a 7-day period. Diet composition estimates obtained by both methods were similar and indicate that Stipagrostis pungens (Desf.) De Winter was the main diet component followed by Fagonia glutinosa Delile, Helianthemum kahiricum Delile, and Hammada schmittiana (Pomel.) Botsch. Data showed that addax have mixed diets composed of perennial woody and herbaceous plant species depending on their availability. The four species most selected by the animals were also the most abundant species in terms of plant cover. In contrast, species that accounted for less than 5% of the plant cover were not present in the fecal samples. Results of this study represent a single grazing season, and for that reason, further studies are required to fully understand how the grazing behaviour of addax varies with seasonal changes in vegetation cover.
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Moreno-de las Heras, M., R. Díaz-Sierra, L. Turnbull, and J. Wainwright. "Assessing vegetation structure and ANPP dynamics in a grassland–shrubland Chihuahuan ecotone using NDVI–rainfall relationships." Biogeosciences 12, no. 10 (May 21, 2015): 2907–25. http://dx.doi.org/10.5194/bg-12-2907-2015.
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Abstract. Climate change and the widespread alteration of natural habitats are major drivers of vegetation change in drylands. In the Chihuahuan Desert, large areas of grasslands dominated by perennial grass species have transitioned over the last 150 years to shrublands dominated by woody species, accompanied by accelerated water and wind erosion. Multiple mechanisms drive the shrub-encroachment process, including precipitation variations, land-use change, and soil erosion–vegetation feedbacks. In this study, using a simple ecohydrological modelling framework, we show that herbaceous (grasses and forbs) and shrub vegetation in drylands have different responses to antecedent precipitation due to functional differences in plant-growth and water-use patterns. Therefore, shrub encroachment may be reflected in the analysis of landscape-scale vegetation–rainfall relationships. We analyse the structure and dynamics of vegetation at an 18 km2 grassland–shrubland ecotone in the northern edge of the Chihuahuan Desert (McKenzie Flats, Sevilleta National Wildlife Refuge, NM, USA) by investigating the relationship between decade-scale (2000–2013) records of remotely sensed vegetation greenness (MODIS NDVI) and antecedent rainfall. NDVI–rainfall relationships show a high sensitivity to spatial variations on dominant vegetation types across the grassland–shrubland ecotone, and provide biophysical criteria to (a) classify landscape types as a function of the spatial distribution of dominant vegetation and to (b) decompose the NDVI signal into partial components of annual net primary production (ANPP) for herbaceous vegetation and shrubs. Analysis of remotely sensed ANPP dynamics across the study site indicates that plant growth for herbaceous vegetation is particularly synchronized with monsoonal summer rainfall. For shrubs, ANPP is better explained by winter plus summer precipitation, overlapping the monsoonal period (June–September) of rain concentration. Our results suggest that shrub encroachment was not particularly active in this Chihuahuan ecotone for the period 2000–2013. However, future changes in the amount and temporal pattern of precipitation (i.e. reductions in monsoonal summer rainfall and/or increases in winter precipitation) may enhance the shrub-encroachment process, particularly in the face of expected upcoming increases in aridity for desert grasslands of the southwestern USA.
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Widrlechner, Mark P., Christopher Daly, Markus Keller, and Kim Kaplan. "Horticultural Applications of a Newly Revised USDA Plant Hardiness Zone Map." HortTechnology 22, no. 1 (February 2012): 6–19. http://dx.doi.org/10.21273/horttech.22.1.6.
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The accurate prediction of winter injury caused by low-temperature events is a key component of the effective cultivation of woody and herbaceous perennial plants. A common method employed to visualize geographic patterns in the severity of low-temperature events is to map a climatological variable that closely correlates with plant survival. The U.S. Department of Agriculture Plant Hardiness Zone Map (PHZM) is constructed for that purpose. We present a short history of PHZM development, culminating in the recent production of a new, high-resolution version of the PHZM, and discuss how such maps relate to winterhardiness per se and to other climatic factors that affect hardiness. The new PHZM is based on extreme minimum-temperature data logged annually from 1976 to 2005 at 7983 weather stations in the United States, Puerto Rico, and adjacent regions in Canada and Mexico. The PHZM is accessible via an interactive website, which facilitates a wide range of horticultural applications. For example, we highlight how the PHZM can be used as a tool for site evaluation for vineyards in the Pacific northwestern United States and as a data layer in conjunction with moisture-balance data to predict the survival of Yugoslavian woody plants in South Dakota. In addition, the new map includes a zip code finder, and we describe how it may be used by governmental agencies for risk management and development of recommended plant lists, by horticultural firms to schedule plant shipments, and by other commercial interests that market products seasonally.
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Cunliffe, Bruce A. "102 Container Production of Ornamental Grasses: The Effects of Propagation Time on Winter Survival and Sale Date." HortScience 34, no. 3 (June 1999): 459A—459. http://dx.doi.org/10.21273/hortsci.34.3.459a.
Full textAbstract:
It is common practice to propagate grasses by division in the spring rather than the fall. This is particularly true of warm-season grasses. Production schedules for grasses do not often fit the general production pattern of other herbaceous perennial or woody crops. Five ornamental grass species were studied: Schizachyrium scoparium, Sporobolus heterolepsis, Calamagrostis × acutiflora `Karl Foerster', Miscanthus sinensis `Purpurascens', and Miscanthus sinensis `Variegatus'. Uniform divisions based on species were planted in 4-inch (480-ml) pots, #1 (2780-ml), and #2 (6240-ml) containers. Fall divisions were done between 28 Oct. and 10 Nov. 1997. Spring divisions occurred between 30 Apr. and 7 May 1998. The experiment is a randomized complete-block design blocking on pot size. All containers were over-wintered under the same cover of plastic, straw, and plastic. Plants were evaluated for post-winter survival and growth. Plants were given a visual rating (0-3) every 2 weeks to assess salability. Spring survival of fall divisions was 99% for S. scoparium, C. × acutiflora `Karl Foerster', and M. sinensis `Purpurascens'. M. sinensis `Variegatus', and S. heterolepsis each had ≈50% survival. Fall divisions reached a salable rating a minimum of 2 weeks ahead of spring divisions. These results indicate that some ornamental grass species may benefit from fall rather than spring handling.
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Graciano, R. M. L., V. P. De Freitas, and M. Ábel. "Simultan sacharification and fermentation of tobacco samples." Analecta Technica Szegedinensia 8, no. 2 (May 12, 2014): 80–89. http://dx.doi.org/10.14232/analecta.2014.2.80-89.
Full textAbstract:
Tobacco plants (Nicotiana rustica, Nicotiana tabacum) produce abundant biomass in more than 100 countries and could be used to produce abundant biofuels. Tobacco is an ideal crop for biobased products; it is a perennial herbaceous plant. About one quarter of the tobacco plant is cellulosic material. Tobacco stem is a by-product in the tobacco industry after the tobacco leaves are harvested. The utilization ratio of tobacco stem is only approximately 40% due to difficulties in the comprehensive utilization technologies of tobacco stem. Therefore most of the tobacco stems have gone to waste. This biomass appears attractive for conversion to ethanol because it contains very low amounts of the hard-to-convert woody material lignin. The aim of this study is to identify the best parameters of the simultaneous saccharification and fermentation (SSF) process on tobacco based substrate. Just to make this technology cheaper, the enzyme recovery was investigated by membrane technology. Polyethersulfone membrane filters with 0.1 µm were used for microfiltration followed by determination of proteins using photometer and Kjeldahl method to measure the enzyme recovery. The aim was to decide whether the microfiltration membrane with cut-off 0.1 µm is a proper membrane for recycling the enzyme. During the filtration, increased resistance and decreased flux were detected.
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Arnold, Michael A., Garry V. McDonald, Geoffrey C. Denny, Sean T. Carver, and Andrew R. King. "Screening Potential New Tropical Ornamentals for Alkalinity, Salinity, and Irradiance Tolerances." Journal of Environmental Horticulture 29, no. 1 (March 1, 2011): 45–50. http://dx.doi.org/10.24266/0738-2898-29.1.45.
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Abstract With the rapid introduction of new herbaceous or woody perennial tropical and subtropical taxa to the U.S. nursery trade for use as summer annuals, methods for quickly assessing their tolerances to various environmental stresses will be needed. Three screening methods, one each for substrate alkalinity, soil salinity, and varied irradiance levels, were tested on four tropical taxa, Rotheca myricoides (Hochst.) Steane & Mabb. (blue butterfly bush), Graptophyllum pictum (L.) Griff, (caricature plant), Jatropha integerrima Jacq. (firecracker jatropha), and Chrysothemis pulchella (Don. ex J. Sims) Desc. (dozakie), with potential for use as summer annuals. Specialized portable structures for testing irradiance levels were developed which minimized confounding of restricted air movement often associated with imposing shade treatments. Irradiance and salinity screening procedures were deemed successful, while further refinement is needed with the alkalinity screening method tested. Decreased irradiance levels suppressed flowering of R. myricoides, while full sun exposure decreased foliar appearance and growth of C. pulchella. Only J. integerrima showed adverse responses to elevated substrate alkalinity. Jatropha integerrima and G. pictum exhibited adaptation to a wide range of light exposures and salinity levels while maintaining attractive foliage. Although flowering of J. integerrima was reduced with heavy shade (66%), some flowering continued.
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Paudel, Asha, Scott H. Markwith, Katie Konchar, Mani Shrestha, and Suresh K. Ghimire. "Anthropogenic fire, vegetation structure and ethnobotanical uses in an alpine shrubland of Nepal’s Himalaya." International Journal of Wildland Fire 29, no. 3 (2020): 201. http://dx.doi.org/10.1071/wf19098.
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Alpine vegetation of the Himalaya is used as food, medicine or fodder, and is commonly managed with fire by agropastoralists. Prescribed fire can have positive effects on rangeland biodiversity, but studies evaluating its effects in alpine shrublands are scarce. Our objective was to examine the effects of anthropogenic fire on biophysical characteristics, species richness, abundance and composition in an alpine shrubland with socioeconomic value to local peoples in Langtang National Park in central Nepal. We surveyed biophysical variables, vascular plant species richness and composition along three transects at ascending elevations, and conducted interviews with local people and park officials on the use of fire in the region. We found 69 species of vascular plants in 89 plots; species richness was greater in burned plots and with increasing elevation, with 13 species unique to burned plots. We identified 14 indicator species in both burned and unburned plots; eight of them were Himalayan endemics. In burned plots, the indicator species were predominantly grasses and perennial forbs with ethnobotanical uses. This is the first detailed study on alpine shrubland anthropogenic fire in the Nepalese Himalaya. Burning may, at least temporarily, replace woody with more palatable herbaceous species, and weaken the elevational gradient of the shrubland.
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Murphy, Anna-Marie, G. Brett Runion, Stephen A. Prior, H. Allen Torbert, Jeff L. Sibley, Glenn B. Fain, and Jeremy M. Pickens. "Effects of Growth Substrate on Greenhouse Gas Emissions from Three Annual Species." Journal of Environmental Horticulture 39, no. 2 (June 1, 2021): 53–61. http://dx.doi.org/10.24266/0738-2898-39.2.53.
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Abstract Previous work by these authors have quantified cumulative greenhouse gas (GHG) emissions for several woody and herbaceous perennial species, in interaction with several standard best management practices (container size, fertilizer application and irrigation delivery methods, and light level). In this study, the greenhouse production of three annual species [coleus (Solenostemon scutellarioides Thonn. ‘Redhead'), vinca (Catharanthus roseus L. ‘Cooler Grape'), and impatiens (Impatiens walleriana Hook. f. ‘Super Elfin XP White')] was evaluated in three substrates [80:20 peat:perlite, 80:20 peat:WholeTree (a whole pine tree-based substrate), 60:40 peat:WholeTree]. Emissions of CO2, N2O and CH4 were collected over a period of 52 days. Without regard to media, coleus had the highest cumulative CO2 efflux (statistically similar to vinca), due to its increased size in comparison with both vinca and impatiens. Without regard to species, plant-pot systems using the highest proportion of WholeTree (40%) had numerically the most cumulative CO2 efflux (statistically similar to those containing only 20% WholeTree). No differences were observed for the main effect of species or media for N2O or CH4. Results suggest that using a more sustainable high wood fiber substrate in similar proportions to that of perlite in an industry standard mix (20%) could yield similarly sized plants with no negative impact on GHG emissions. Index words: alternative substrate, WholeTree, carbon sequestration, carbon dioxide, nitrous oxide, methane, global climate change. Species used in this study: ‘Redhead' coleus, Solenostemon scutellarioides Thonn. ‘Redhead'; ‘Cooler Grape' vinca, Catharanthus roseus L. ‘Cooler Grape'; ‘Super Elfin XP White' impatiens, Impatiens walleriana Hook. f. ‘Super Elfin XP White'.
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Zheng, Tangchun, Xiaokang Zhuo, Lulu Li, Tangren Cheng, and Qixiang Zhang. "Genome-Wide Analysis of the D-type Cyclin Gene Family Reveals Differential Expression Patterns and Stem Development in the Woody Plant Prunus mume." Forests 10, no. 2 (February 10, 2019): 147. http://dx.doi.org/10.3390/f10020147.
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Cyclins, a prominent class of cell division regulators, play an extremely important role in plant growth and development. D-type cyclins (CYCDs) are the rate-limiting components of the G1 phase. In plants, studies of CYCDs are mainly concerned with herbaceous plants, yet little information is available about these genes in perennial woody plants, especially ornamental plants. Here, twelve Prunus mume CYCD (PmCYCDs) genes are identified and characterized. The PmCYCDs were named on the basis of orthologues in Arabidopsis thaliana and Oryza sativa. Gene structure and conserved domains of each subgroup CYCDs was similar to that of their orthologues in A. thaliana and O. sativa. However, PmCYCDs exhibited different tissue-specific expression patterns in root, stem, leaf, bud, and fruit organs. The results of qRT-PCR showed that all PmCYCDs, except PmCYCD5;2 and PmCYCD7;1, were primarily highly expressed in leaf buds, shoots, and stems. In addition, the transcript levels of PmCYCD genes were analyzed in roots under different treatments, including exogenous applications of NAA, 6-BA, GA3, ABA, and sucrose. Interestingly, although PmCYCDs were induced by sucrose, the extent of gene induction among PmCYCD subgroups varied. The induction of PmCYCD1;2 by hormones depended on the presence of sucrose. PmCYCD3;1 was stimulated by NAA, and induction was strengthened when sugar and hormones were applied together. Taken together, our study demonstrates that PmCYCDs are functional in plant stem development and provides a basis for selecting members of the cyclin gene family as candidate genes for ornamental plant breeding.
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Heinl, Michael, Jan Sliva, Michael Murray-Hudson, and Budzanani Tacheba. "Post-fire succession on savanna habitats in the Okavango Delta wetland, Botswana." Journal of Tropical Ecology 23, no. 6 (October 29, 2007): 705–13. http://dx.doi.org/10.1017/s0266467407004452.
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Drying floodplains that were not inundated for more than 10 y were investigated to relate plant species and vegetation structure to time-since-fire for the southern Okavango Delta wetland in Botswana. The aims of the research were to study post-fire succession on savanna habitats in the Okavango Delta and to investigate the mechanisms behind vegetation changes with time-since-fire. We hypothesize that vegetation structure rather than species occurrence is affected by the fire event and that the driving forces of post-fire succession change from fire-driven to competition-driven with increasing time-since-fire. A total number of 153 study sites were investigated, representing areas of 2–12 y without a fire. Both woody and herbaceous plant species were recorded and cover/abundance values were measured. The vegetation changes with time-since-fire could be assigned to three different successional stages: (1) the post-fire conditions shortly after fire, supporting high species numbers due to open space and little competition; (2) the dominance of competitive perennial grass species (e.g. Urochloa mosambicensis) after 6–8 y; and (3) the enhanced establishment of woody species after about 10 y, creating new habitats in their vicinity. High species numbers were found after short and long fire-free periods, and different species occurred shortly after the fire event and at late stages of the post-fire succession. A variety of different inter-fire intervals is therefore expected to be responsible for sustaining plant species richness and habitat diversity in the study area. Post-fire succession could be described as not only being driven by the life history of the species, but also by seedbank dynamics and plant mobility in early successional stages and by competition and niche differentiation in late-successional stages.
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Weiersbye, I. M., E. T. F. Witkowski, and M. Reichardt. "Floristic composition of gold and uranium tailings dams, and adjacent polluted areas, on South Africa’s deep-level mines." Bothalia 36, no. 1 (August 20, 2006): 101–27. http://dx.doi.org/10.4102/abc.v36i1.349.
Full textAbstract:
Gold and uranium tailings (‘slimes’) dams and the adjacent polluted soils in the deep-level mining regions of South Africa (Carletonville, Klerksdorp and Welkom) were surveyed for the frequency of occurrence of naturally colonizing, actively introduced and persisting plant species. Fifty-six tailings dams with a combined area of 5864 ha. and a similar area o f tail- ings-polluted soils, were surveyed between July 1996 and March 1997. During the survey, 376 plant species and subspecies were recorded from the dams and adjacent polluted soils, with an additional 8 6 records obtained between 1998 and 2003 (i.e. a total of 462 taxa: species and infraspecific species). Overall, the most commonly represented families were the Poaceae (107 species and subspecies), Asteraceae (81). Fabaceae (55) and Anacardiaceae (16). with other families represented by just one to 14 species. Only 60 species were common to all three regions, and of these 24 had been introduced during rehabilitation attempts. Most of the species found on tailings were persisters or natural colonizers (53-88%, depending on substrate), with the vast majority being indigenous and perennial taxa (76% and 85% respectively), with semi-woody to woody growth forms (6 6% being resprouters, forbs, shrubs and trees). Less than 4% of the naturally-colonizing taxa found during the survey had also been introduced by vegetation practitioners. The majority of introduced plants were alien herbaceous taxa. The number and frequency of annuals was only high on recently vegetated sites, whereas annuals were rarely present on old-vegetated and never-vegetated dams. This list includes a wide range of indigenous plant species that may be suitable for phytoremediation of tailings dams and polluted soils due to their apparent tolerance of acid mine drainage and salinity.
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Swanson, Bert T., and James B. Calkins. "Weed Control Strategies for Field- and Container-grown Herbaceous Perennials." HortScience 30, no. 4 (July 1995): 894E—894. http://dx.doi.org/10.21273/hortsci.30.4.894e.
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Fourteen herbicides or herbicide combinations, a wood chip mulch, a chipped rubber tire mulch, and a newspaper mulch were evaluated for weed control efficacy and potential phytotoxicity using 12 species of herbaceous perennials under field-growing conditions. Nineteen herbicides or herbicide combinations were similarly evaluated under container-growing conditions using 11 species of herbaceous perennials. The effect of herbicide application time also was monitored through application of herbicides to dormant and actively growing plants. Herbicides and mulch treatments were compared to weeded and nonweeded controls. Herbicide phytotoxicity effects were dependent on the age and species of the herbaceous perennial and herbicide application timing. Herbicide injury was generally greater for newly established plants compared to established plants. Although injury was usually reduced when herbicides were applied to dormant plants, injury was sometimes greater when herbicides were applied in early spring compared to applications made in late spring after complete herbaceous perennial emergence. This effect resulted in injury to young shoots that had emerged before the earliest possible time that herbicides could be applied in early spring. A wood chip mulch provided the most effective weed control and highest quality plants under field growing conditions. Several of the herbicides evaluated demonstrated potential for weed control in both field and container herbaceous perennial production systems and landscape plantings.
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Murphy, Anna-Marie, G. Brett Runion, Stephen A. Prior, H. Allen Torbert, Jeff L. Sibley, Glenn B. Fain, and Jeremy M. Pickens. "Effects of Fertilizer Placement on Greenhouse Gas Emissions from a Sun and Shade Grown Ornamental Crop1." Journal of Environmental Horticulture 37, no. 3 (September 1, 2019): 74–80. http://dx.doi.org/10.24266/0738-2898-37.3.74.
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Abstract The level to which ornamental plant production impacts rising atmospheric greenhouse gas (GHG) concentrations remains unknown. Research to date has focused on developing baseline estimations of GHG emissions from plant-pot production systems and their contribution to global warming potential. To date, pot size, irrigation delivery method and fertilizer application method have been evaluated in the production of common woody ornamental crops. In this study, two perennial herbaceous plants, full-sun-grown ‘Stella D'Oro' daylily (Hemerocallis × ‘Stella D'Oro' L.) and shade-grown ‘Royal Standard' hosta (Hosta × ‘Royal Standard') (Hosta plantaginea Aschers × Hosta sieboldiana N.Fujita) were grown utilizing one of three common fertilizer application methods (dibbled, incorporated or top-dressed). Plants were grown in 3.8 L (1 gal) nursery containers in a 6:1 pinebark:sand substrate with standard amendments. Gas samples were collected in situ according to standard GRACEnet protocols weekly for five months. Cumulative emissions for both CO2 and N2O were least for plant-pot systems using the dibbled fertilizer method, regardless of species. Cumulative CO2 emissions were highest for plants fertilized by incorporation, followed by those fertilized by top-dressing. No differences were observed between N2O efflux measurements for systems fertilized by either the incorporated or top-dressed methods. Results suggest that dibbling fertilizer could significantly decrease both CO2 and N2O emission. Index words: carbon dioxide, nitrous oxide, methane, trace gas. Species used in this study: ‘Stella D'Oro' daylily (Hemerocallis × ‘Stella D'Oro' L.); ‘Royal Standard' hosta [(Hosta × ‘Royal Standard') (Hosta plantaginea Aschers × Hosta sieboldiana N.Fujita)].