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1
Vitt, Dale H., Melissa House, and Jeremy A. Hartsock. "Sandhill Fen, an initial trial for wetland species assembly on in-pit substrates: lessons after three years." Botany 94, no. 11 (November 2016): 1015–25. http://dx.doi.org/10.1139/cjb-2015-0262.
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Open-pit mining of oil sands removes wetland plant communities from the landscape. Sandhill Watershed, located on Syncrude Canada’s oil sands lease, is the first reclamation of a complex watershed that includes a 17 ha central wetland designed to develop into a rich fen. Here we sample the vegetation after three years. Of the 124 plant species recorded, 48% are peat-forming species, including 24 bryophyte species. We identified, using ordination techniques, four plant assemblages that vary in abundance of peat-forming plants. Each assemblage occurs in a spatially distinct area of Sandhill Fen, forming vegetation zones that are closely associated with height of water table. The plant assemblage distributed in the wettest areas has abundant marsh species. The assemblages in the driest areas of the fen have large numbers of upland and weed species and few species characteristic of fens. In between is a species assemblage with an abundance of species characteristic of natural peat-forming habitats. Two key findings are: water levels control spatial distributions of species assemblages, and non-peat-forming plant species are abundant and a concern for the establishment of peat-forming wetlands. Future designs should include plans for a number of interconnected site types such as marshes, fens, and riparian areas.
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Fansong, Meng. "Middle Triassic lycopsid flora of South China and its palaeoecological significance." Journal of Palaeosciences 45 (December 31, 1996): 334–43. http://dx.doi.org/10.54991/jop.1996.1253.
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In recent years, a flora characterized by Lycopsida has been found from the Middle Triassic Badong Formation in Yangtze Gorge area, China, and may be subdivided into two plant assemblages, i.e., Anisian, Pleuromeia, marginulata-Annalepis sangzhiensis assemblage and Ladinian Annalepislatiloba-Scytophyllum assemblage. Of them, the former assemblage, containing 18 genera and 30 species, is one of the typical floras of the tidal flat in the world during Anisian. In addition, the character and ecology of the Anisian plant assemblage are emphatically discussed in this paper.
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Van-Silva, Wilian, Andrei Guimarães Guedes, Priscila Lemes de Azevedo-Silva, Fernanda Francisca Gontijo, Rosana Silva Barbosa, Gustavo Ribeiro Aloísio, and Flávio César Gomes de Oliveira. "Herpetofauna, Espora Hydroelectric Power Plant, state of Goiás, Brazil." Check List 3, no. 4 (November 1, 2007): 338. http://dx.doi.org/10.15560/3.4.338.
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We provide a checklist of the herpetofaunal assemblage from Espora Hydroelectric Power Plant region (UHE Espora), southwestern of the state of Goiás, Brazil. Representatives of 32 amphibian and 71 reptile species were obtained during faunal monitoring and faunal rescue programs carried out in the study area. The obtained species list and distribution records are here discussed in an attempt to improve the still limited knowledge on Cerrado herpetofaunal assemblages.
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CALDARA, ROBERTO, DAVIDE SASSI, and IVO TOŠEVSKI. "Phylogeny of the weevil genus Rhinusa Stephens based on adult morphological characters and host plant information (Coleoptera: Curculionidae)." Zootaxa 2627, no. 1 (September 27, 2010): 39. http://dx.doi.org/10.11646/zootaxa.2627.1.3.
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A phylogenetic analysis of the species belonging to the weevil genus Rhinusa Stephens, 1829 (Coleoptera: Curculionidae: Curculioninae: Mecinini) was carried out. Rhinusa weevils feed on plants of the closely related families Scrophulariaceae and Plantaginaceae. Based on a cladistic analysis of six outgroup and 33 ingroup taxa, and 39 adult morphological and 8 ecological characters, eight well supported species groups and two monobasic groups belonging to three separate and more inclusive assemblages were recognized. The first assemblage (A) includes nine species belonging to two groups (R. bipustulata and R. tetra groups), whereas the second and third assemblages (B and C) include a total of 14 species belonging to two groups (R. antirrhini and R. linariae groups) and six groups (R. pilosa, R. herbarum, R. neta, R. vestita, R. mauritii and R. melas groups), respectively. Two of the three main assemblages (A and B) are well supported as monophyletic entities, whereas the third assemblage (C) has weak support contingent in part upon the exclusion of host plant associations. Assemblage A includes all species living on species of Scrophulariaceae, with two groups occurring on two closely related plant genera, Scrophularia (R. bipustulata group) and Verbascum (R. tetra group), respectively. The other two assemblages include species living exclusively on species of the family Plantaginaceae, tribe Antirrhineae. These patterns suggest a well conserved and phylogenetically congruent association among the weevils and their hosts. Optimizing host plant preferences onto the morphological phylogeny indicates that feeding on Plantaginaceae was the plesiomorphic condition for the genus Rhinusa. In general there are no strict relationships between groups of weevils and their specific feeding habits; however, species of the R. antirrhini group are all feeding on seed capsules. In contrast, in other groups the larvae of closely related species display significant variations in host plant parasitism. Some species of the R. tetra group feed on seed capsules whereas others are stem borers. In turn, certain species of the R. neta group feed on seed capsules yet others are inquilines of gall forming species of Rhinusa. The latter habit is present in multiple convergent groups such as the R. linariae and R. pilosa groups.
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Kooyman, Robert M. "Traits and gradients influence the canopy position of small-statured rain forest trees." Australian Journal of Botany 60, no. 8 (2012): 735. http://dx.doi.org/10.1071/bt12195.
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Plant height determines a species’ position in the canopy and regulates access to light. Shifts in trait values for assemblages (plots) arrayed along abiotic gradients can reflect changes in species composition, and shifts in species trait values. Multivariate analysis was used to quantify the relationship of assemblage-level floristic composition to environmental gradients. Species trait values for maximum height, leaf area, seed size and wood density were quantified for woody species in the assemblage samples, and partitioned into within- and among-assemblage components to enable trait correlations to be identified, including in relation to abiotic gradients. Assemblages in upslope topographic positions had lower height, smaller leaves and higher wood density. Across the assemblages, shifts in species composition, decreasing canopy height and the position of smaller trees in the canopy were all linked to decreasing soil depth in upslope topographic positions. Regardless of stand height, the canopy position of most main canopy dominants remained largely unchanged in response to shifts in environmental gradients. In contrast, shorter-stature tree species retained height along the gradient and subsequently shifted from the subcanopy to the canopy as soil depth and site (plot) canopy height decreased. Within a community, height and position in the canopy can shift under differing environmental conditions.
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Wellman, Charles. "A land plant microfossil assemblage of Mid Silurian age from the Stonehaven Group, Scotland." Journal of Micropalaeontology 12, no. 1 (August 1, 1993): 47–66. http://dx.doi.org/10.1144/jm.12.1.47.
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Abstract. Land plant microfossils recovered from the Stonehaven Group near Stonehaven, Scotland comprise sporomorphs (cryptospores and miospores) and plant fragments (tubular structures and cuticle-like sheets). A new species of hilate cryptospore, Hispanaediscus lamontii sp. nov., is proposed. The sporomorph assemblage indicates a late Wenlock, or possibly earliest Ludlow age and is interpreted as accumulating in a continental environment. The new age constraint suggests that the Stonehaven Group is not in continuous succession with overlying “Lower Old Red Sandstone” deposits and should be treated separately. The assemblage provides important information regarding the composition of Mid Silurian continental plant microfossil assemblages and indicates that the vegetation comprised few taxa and was cosmopolitan.
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Lee, Philip. "The impact of burn intensity from wildfires on seed and vegetative banks, and emergent understory in aspen-dominated boreal forests." Canadian Journal of Botany 82, no. 10 (October 1, 2004): 1468–80. http://dx.doi.org/10.1139/b04-108.
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This paper compares seed and vegetative banks, and the emergent understory in unburned, lightly burned, and intensely burned patches within an aspen-dominated boreal forest in northeastern Alberta, Canada. Propagule banks were measured immediately after the fire, while the understory was surveyed 2 years later. Seedling and shoot emergence techniques were used to assess the abundance and assemblage of species within seed and vegetative banks. Median seed density was ordered unburned > lightly burned = intensely burned patches. A cumulative index of vegetative bank abundance was ordered unburned > lightly burned > intensely burned patches. Species assemblages were significantly different amongst burn intensities for seed banks and emergent understory. Vegetative bank assemblages were significantly different between unburned and burned patches but not between lightly and intensely burned patches. Furthermore, seed and vegetative bank assemblages within each burn intensity were also significantly different. Indicator species analysis suggested that all significant differences were due largely to broad assemblage differences rather than a few unique species. Ordination with nonmetric multidimensional scaling correspondence analysis separated seed and vegetative banks, and emergent understory along two axes (88.8% of the total variation). The first axis (50.3% of the total variation) indicated that the unburned and lightly burned species assemblages were more similar to the vegetative bank, while the intensely burned patches were more similar to the seed bank. The second axis (38.5% of the total variation) placed vegetative banks closer to emergent vegetation than seed banks.Key words: seed bank, bud bank, vegetative bank, aspen, boreal, fire.
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Naeem, Shahid, Katarina Håkansson, John H. Lawton, M. J. Crawley, Lindsey J. Thompson, and Katarina Hakansson. "Biodiversity and Plant Productivity in a Model Assemblage of Plant Species." Oikos 76, no. 2 (June 1996): 259. http://dx.doi.org/10.2307/3546198.
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Bourceret, Amélia, Corinne Leyval, François Thomas, and Aurélie Cébron. "Rhizosphere effect is stronger than PAH concentration on shaping spatial bacterial assemblages along centimetre-scale depth gradients." Canadian Journal of Microbiology 63, no. 11 (November 2017): 881–93. http://dx.doi.org/10.1139/cjm-2017-0124.
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At centimetre scale, soil bacterial assemblages are shaped by both abiotic (edaphic characteristics and pollutants) and biotic parameters. In a rhizobox experiment carried out on planted industrial soil contaminated with polycyclic aromatic hydrocarbons (PAHs), we previously showed that pollution was distributed randomly with hot and cold spots. Therefore, in the present study, we investigated the effect of this patchy PAH distribution on the bacterial community assemblage and compared it with that of root depth gradients found in the rhizosphere of either alfalfa or ryegrass. Sequencing of 16S rRNA amplicons revealed a higher bacterial diversity in ryegrass rhizosphere and enrichment in specific taxa by the 2 plant species. Indeed, Bacteroidetes, Firmicutes, and Gammaproteobacteria were globally favored in alfalfa, whereas Acidimicrobiia, Chloroflexi, Alpha-, and Betaproteobacteria were globally favored in ryegrass rhizosphere. The presence of alfalfa created depth gradients of root biomass, carbohydrate, and pH, and actually shaped the bacterial assemblage, favoring Actinobacteria near the surface and Gemmatimonadetes and Proteobacteria at greater depths. Contrarily, the bacterial assemblage was homogeneous all along depths of the ryegrass root system. With both plant species, the PAH content and random distribution had no significant effect on bacterial assemblage. Globally, at centimeter scale, bacterial community assemblages were mostly shaped by soil physical and chemical depth gradients induced by root growth but not by patchy PAH content.
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Bernardes, Carolina, and Flávia Regina Capellotto Costa. "Environmental variables and Piper assemblage composition: a mesoscale study in the Madeira-Purus interfluve, Central Amazonia." Biota Neotropica 11, no. 3 (September 2011): 83–91. http://dx.doi.org/10.1590/s1676-06032011000300006.
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This study aimed to determine the effects of canopy openness, litter depth, soil cation content and texture on Piper assemblage composition at a mesoscale. Piper assemblage composition and environmental variables were inventoried in 41 0.125 ha (250 × 5 m) plots placed in a terra firme forest located in the Madeira-Purus interfluve, Central Amazonia. Ordination of the 41 plots by Non-metric Multidimensional Scaling (NMDS) in one dimension captured 58% of the floristic variation and was used as the response variable in multiple regression models. Environmental variables explained 39% of the variation in Piper assemblage composition, which was significantly related to litter depth, soil texture and canopy openness, but not to the cation content. Effects of edaphic components on plant assemblage structure have been reported for different plant groups, however the strong effect of litter depth at a mesoscale had not yet been demonstrated. We suggest that litter depth variation not only influences the structure of Piper assemblages, but also of other plant groups at a mesoscale, as this environmental variable has a direct or indirect effect on species germination and establishment.
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Ninot, Josep M., Oriol Grau, Empar Carrillo, Roser Guàrdia, Artur Lluent, and Estela Illa. "Functional Plant Traits and Species Assemblage in Pyrenean Snowbeds." Folia Geobotanica 48, no. 1 (October 11, 2012): 23–38. http://dx.doi.org/10.1007/s12224-012-9138-9.
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Labadessa, Rocco, Luigi Forte, and Paola Mairota. "Exploring Life Forms for Linking Orthopteran Assemblage and Grassland Plant Community." Hacquetia 14, no. 1 (June 1, 2015): 33–42. http://dx.doi.org/10.1515/hacq-2015-0012.
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AbstractOrthopterans are well known to represent the majority of insect biomass in many grassland ecosystems. However, the verification of a relationship between the traditional descriptors of orthopteran assemblage structure and plant community patterns is not straightforward. We explore the usefulness of the concept of life forms to provide insights on such ecosystem level relationship. For this purpose, thirty sample sites in semi-natural calcareous grasslands were classified according to the relative proportion of dominant herbaceous plant life forms. Orthopteran species were grouped in four categories, based on the Bei-Bienko’s life form categorization. The association among plant communities, orthopteran assemblages and environmental factors was tested by means of canonical correspondence analysis. Orthoptera groups were found to be associated with distinct plant communities, also indicating the effect of vegetation change on orthopteran assemblages. In particular, geobionta species were associated with all the most disturbed plant communities, while chortobionta and thamnobionta seemed to be dependent on better preserved grassland types. Therefore, the use of life forms could help informing on the relationships of orthopteran assemblages with grassland conservation state. Information on such community relationships at the local scale could also assist managers in the interpretation of habitat change maps in terms of biodiversity changes.
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Wilson, Gaius, Ajay A. Desai, Dalice A. Sim, Monica A. M. Gruber, and Philip J. Lester. "The association between invasive Lantana camara and seedlings/saplings of a plant community in Mudumalai Tiger Reserve, India." Journal of Tropical Ecology 30, no. 6 (August 8, 2014): 551–63. http://dx.doi.org/10.1017/s026646741400039x.
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Abstract:We examined changes in a community of seedlings/saplings 10–150 cm tall associated with the presence of a widely invasive plant, Lantana camara and environmental covariates along 67 randomly located transects, in Mudumalai, India. We compared plant species assemblage and grass cover in L. camara-invaded and uninvaded plots in three habitats. Multivariate analyses revealed a significant association of all environmental covariates with plant species assemblage. Pairwise tests indicated that L. camara was significantly associated with changes in plant species assemblage and grass cover within the moist and dry deciduous forest, but not in the thorn forest. The relationship between L. camara and that of elephant browse plants varied with species. A linear regression analysis indicated that L. camara invasion was the only significant predictor of grass occupancy. Our results indicate that in addition to other factors, L. camara was associated with altering plant species assemblage, some elephant browse plants and grass cover in the moist and dry deciduous forest. It appears that L. camara can have a major effect on diversity within this reserve, but whether this effect is by L. camara driving the change or being associated with other habitat change requires further experimental evidence.
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Harris, M. Anne, Brian F. Cumming, and John P. Smol. "Assessment of recent environmental changes in New Brunswick (Canada) lakes based on paleolimnological shifts in diatom species assemblages." Canadian Journal of Botany 84, no. 1 (January 2006): 151–63. http://dx.doi.org/10.1139/b05-157.
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New Brunswick lakes are subjected to multiple environmental stressors, such as atmospheric acid deposition and climate change. In the absence of long-term environmental data, the impacts of these stressors are not well understood. Long-term effects of environmental change on diatom species assemblages were assessed in the sediments of 16 New Brunswick lakes using paleolimnological approaches. A regional trend of increasing Cyclotella stelligera Cleve & Gunrow and decreasing Aulacoseira species complex was recorded in most lakes. Detailed paleolimnological analyses of Wolfe, Cundy, and West Long lakes revealed varying degrees of species change, with assemblage shifts beginning ca. 1900 CE (common era). These species trends are not consistent with acidification. However, linear regression of mean July temperature with time for two New Brunswick historical instrumental temperature records revealed statistically significant warming over the past century. The shift from heavily silicified tychoplanktonic Aulacoseira species to small planktonic diatom species, such as C. stelligera, is consistent with paleolimnological inferences of warming trends recorded in several other lake regions of the Northern Hemisphere. These assemblage shifts are likely due to recent climate change and may be mediated by reduced ice cover and (or) increased thermal stability (decreased lake mixing) during the open water period.
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Moraes, Vinicius de S., Samuel N. Nunes, Peterson R. Demite, and Rodrigo D. Daud. "Vegetation structure define mite assemblage on plants: a case study in Cerrado biome." Entomological Communications 4 (September 1, 2022): ec04029. http://dx.doi.org/10.37486/2675-1305.ec04029.
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We compared abundance and richness of mites on Miconia albicans (Sw.) Steud. (Melastomataceae) found in Cerrado grassland (CGR) and in Cerrado sensu stricto (CSS), in order to evaluate the effect of plant physiognomy on mite assemblage structure, in the Parque Nacional das Emas, Goiás State, Brazil, a biological reserve of Cerrado biome. In total, 453 mites of 45 species belonging to 14 families were collected. Stigmaeidae was the most abundant predatory mite family, represented by a single unidentified Agistemus species. Among phytophagous mites, species of Lorryia (Tydeidae) were the most common. Lorryia turrialbensis Baker, 1968 is reported for the first time on a Cerrado plant species. We concluded that the Cerrado phytophysiognomy can determine the organization of mite assemblages since CSS sheltered higher species richness and abundance of mites on M. albicans due to has more habitat complexity, species richness and abundance of plants than CGR. Therefore, CSS can provide more food resources, microhabitats for shelter and oviposition favoring the occurrence and populational development of plant mites.
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Toefy, R., I. K. McMillan, and M. J. Gibbons. "The effect of wave exposure on the foraminifera of Gelidium pristoides." Journal of the Marine Biological Association of the United Kingdom 83, no. 4 (August 2003): 705–10. http://dx.doi.org/10.1017/s0025315403007677h.
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The foraminifera of Gelidium pristoides were examined on exposed and sheltered shores around False Bay, South Africa, during the summer and winter of 1998/1999. Twenty-five species were recognized, seven are potentially new. Multivariate statistics indicated that the assemblages on plants from exposed shores were distinct from those on sheltered shores, and two species of foraminifera were confined to exposed shores. Plant size and the quantity of trapped sediment were positively correlated, and plants on exposed shores were significantly bigger than those on sheltered shores. Plant size and sediment weight were linked to assemblage diversity and abundance; assemblages on exposed shores were generally more diverse and abundant than those of sheltered shores. Different species dominated on the two shore types, and larger foraminifera tended to be more common on exposed shores.
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Rezki, Samir, Claire Campion, Beatrice Iacomi-Vasilescu, Anne Preveaux, Youness Toualbia, Sophie Bonneau, Martial Briand, et al. "Differences in stability of seed-associated microbial assemblages in response to invasion by phytopathogenic microorganisms." PeerJ 4 (April 11, 2016): e1923. http://dx.doi.org/10.7717/peerj.1923.
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Seeds are involved in the vertical transmission of microorganisms from one plant generation to another and consequently act as reservoirs for the plant microbiota. However, little is known about the structure of seed-associated microbial assemblages and the regulators of assemblage structure. In this work, we have assessed the response of seed-associated microbial assemblages ofRaphanus sativusto invading phytopathogenic agents, the bacterial strainXanthomonas campestrispv.campestris(Xcc) 8004 and the fungal strainAlternaria brassicicolaAbra43. According to the indicators of bacterial (16S rRNA gene andgyrBsequences) and fungal (ITS1) diversity employed in this study, seed transmission of the bacterial strainXcc8004 did not change the overall composition of resident microbial assemblages. In contrast seed transmission of Abra43 strongly modified the richness and structure of fungal assemblages without affecting bacterial assemblages. The sensitivity of seed-associated fungal assemblage to Abra43 is mostly related to changes in relative abundance of closely related fungal species that belong to theAlternariagenus. Variation in stability of the seed microbiota in response toXccand Abra43 invasions could be explained by differences in seed transmission pathways employed by these micro-organisms, which ultimately results in divergence in spatio-temporal colonization of the seed habitat.
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Chen, Duo, and Mark van Kleunen. "Competitive effects of plant invaders on and their responses to native species assemblages change over time." NeoBiota 73 (April 26, 2022): 19–37. http://dx.doi.org/10.3897/neobiota.73.80410.
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Alien plant invaders are often considered to be more competitive than natives, and species-rich plant communities are often considered to be more resistant to invaders than species-poor communities. However, the competitive interactions between invaders and assemblages of different species richness are unlikely to be static over time (e.g. during a growth season). To test this, we grew five alien and five native species as invaders in a total of 21 artificial assemblages of one, two or four native competitor species. To test for temporal changes in the reciprocal effects of invaders and the competitor assemblages on each other, and how these depend on the species richness of the assemblages, we harvested plants at three growth stages (weeks 4, 8 and 12). We found that the invaders and competitor assemblages had negative effects on each other. Aboveground biomass of invaders was reduced by the presence of a competitor assemblage, irrespective of its species richness, and this difference gradually increased over time. Alien invaders accumulated more aboveground biomass than the native invaders, but only after 12 weeks of growth. Meanwhile, the invaders also negatively affected the biomass of the competitor assemblages. For multi-species assemblages, the increase in the negative effect of the presence of the invader occurred mainly between weeks 4 and 8, whereas it happened mainly between weeks 8 and 12 for the one-species assemblages. Our results suggest that although alien invaders are more competitive than native invaders, the competitive effects of the invaders on and their responses to native competitor assemblages changed over time, irrespective of the origin of the invaders.
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Chen, Duo, and Mark van Kleunen. "Competitive effects of plant invaders on and their responses to native species assemblages change over time." NeoBiota 73 (April 26, 2022): 19–37. http://dx.doi.org/10.3897/neobiota.73.80410.
Full textAbstract:
Alien plant invaders are often considered to be more competitive than natives, and species-rich plant communities are often considered to be more resistant to invaders than species-poor communities. However, the competitive interactions between invaders and assemblages of different species richness are unlikely to be static over time (e.g. during a growth season). To test this, we grew five alien and five native species as invaders in a total of 21 artificial assemblages of one, two or four native competitor species. To test for temporal changes in the reciprocal effects of invaders and the competitor assemblages on each other, and how these depend on the species richness of the assemblages, we harvested plants at three growth stages (weeks 4, 8 and 12). We found that the invaders and competitor assemblages had negative effects on each other. Aboveground biomass of invaders was reduced by the presence of a competitor assemblage, irrespective of its species richness, and this difference gradually increased over time. Alien invaders accumulated more aboveground biomass than the native invaders, but only after 12 weeks of growth. Meanwhile, the invaders also negatively affected the biomass of the competitor assemblages. For multi-species assemblages, the increase in the negative effect of the presence of the invader occurred mainly between weeks 4 and 8, whereas it happened mainly between weeks 8 and 12 for the one-species assemblages. Our results suggest that although alien invaders are more competitive than native invaders, the competitive effects of the invaders on and their responses to native competitor assemblages changed over time, irrespective of the origin of the invaders.
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Zimmer, Kyle D., Mark A. Hanson, and Malcolm G. Butler. "Relationships among nutrients, phytoplankton, macrophytes, and fish in prairie wetlands." Canadian Journal of Fisheries and Aquatic Sciences 60, no. 6 (June 1, 2003): 721–30. http://dx.doi.org/10.1139/f03-060.
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Phytoplankton abundance and nutrient concentrations in shallow-water ecosystems are influenced by submerged macrophytes, zooplankton, and fish, but few studies have simultaneously assessed the influence of all three variables. We sampled 18 semipermanent prairie wetlands for 5 years to assess influences of minnows, submersed macrophytes, cladocerans, and drainage history on phytoplankton abundance and concentrations of nitrogen (N) and phosphorus (P). Our macrophyte data reflect the abundance of three distinct species assemblages (Chara, Potamogeton, and Myriophyllum assemblages) typical of these wetlands. Partial redundancy analysis showed only the Chara and Potamogeton assemblages and fish to be significantly related to algal abundance, N, and P. Macrophytes and fish together explained 40% of the total variance, but the Chara assemblage explained threefold, and the Potamogeton assemblage twofold, more variance than did presence/absence of fish. However, relationships with N and P differed for the two groups of macrophytes: P showed a strong negative relationship with both plant assemblages, and N showed a weak negative relationship with Chara but no relationship with Potamogetons. Our results indicate that phytoplankton and nutrient concentrations in prairie wetlands are strongly influenced by submersed macrophytes, although influences may depend on plant community composition.
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Zheng, Fuchao, Xiaoming Mou, Jinghua Zhang, Tiange Zhang, Lu Xia, Shenglai Yin, Lingye Wu, Xin Leng, Shuqing An, and Dehua Zhao. "Gradual Enhancement of the Assemblage Stability of the Reed Rhizosphere Microbiome with Recovery Time." Microorganisms 10, no. 5 (April 29, 2022): 937. http://dx.doi.org/10.3390/microorganisms10050937.
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Rhizoplane microbes are considered proxies for evaluating the assemblage stability of the rhizosphere in wetland ecosystems due to their roles in plant growth and ecosystem health. However, our knowledge of how microbial assemblage stability is promoted in the reed rhizosphere of wetlands undergoing recovery is limited. We investigated the assemblage stability, diversity, abundance, co-occurrence patterns, and functional characteristics of reed rhizosphere microbes in restored wetlands. The results indicated that assemblage stability significantly increased with recovery time and that the microbial assemblages were capable of resisting seasonal fluctuations after more than 20 years of restoration. The number of bacterial indicators was greater in the restoration groups with longer restoration periods. Most bacterial indicators appeared in the 30-year restoration group. However, the core taxa and keystone species of module 2 exhibited greater abundance within longer recovery periods and were well organized, with rich and diverse functions that enhanced microbial assemblage stability. Our study provides insight into the connection between the rhizosphere microbiome and recovery period and presents a useful theoretical basis for the empirical management of wetland ecosystems.
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Riaux-Gobin, Catherine. "The diatom genus Cocconeis from an intertidal mud flat of North Brittany: source and diversity." Canadian Journal of Botany 69, no. 3 (March 1, 1991): 597–601. http://dx.doi.org/10.1139/b91-081.
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A 1 -year survey of an epipelic diatom assemblage from a North Brittany marine mud flat revealed the presence of 23 species of Cocconeis. About 10 of these species were common, and the remaining ones were rare. These species of Cocconeis for the most part have small dimensions (nannophytobenthos). The species collected from the intertidal sediment, the specific richness, and seasonal occurrences are compared with those of an epiphytic assemblage on Zostera marina L. from the same region. Key words: benthic diatoms, Cocconeis, North Brittany, mud flat.
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Givens, Charles R., and Florence Montgomery Givens. "Age and Significance of Fossil White Spruce (Picea glauca), Tunica Hills, Louisiana-Mississippi." Quaternary Research 27, no. 3 (May 1987): 283–96. http://dx.doi.org/10.1016/0033-5894(87)90084-6.
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AbstractRadiocarbon dates indicate a Farmdalian through Woodfordian age for fossil white spruce (Picea glauca) in the Tunica Hills, a greater time span than previously documented. These dates, furthermore, require revision of the ages of fluvial terrace deposits in the region. Spruce-bearing Terrace 1 sediments, previously regarded as late Woodfordian to Holocene age, are of Farmdalian to late Holocene age. Terrace 2 sediments, previously assigned a Sangamonian or Farmdalian age, are of probable Altonian age. Plant fossils in Terrace 1 sediments represent two climatically and temporally distinct assemblages: a cool-temperate, Farmdalian-Woodfordian assemblage dominated by white spruce but including deciduous hardwoods suggestive of an oak-hickory association; and a warm-temperate Holocene assemblage composed of southern hardwoods and nonarboreal species representative of the modern flora of the Tunica Hills. Locally, fossils of white spruce have been reworked into younger Terrace 1 sediments containing the warm-temperate plant assemblage. The transition from the cool-temperate flora to the modern warm-temperate flora in the Tunica Hills probably occurred around 12,000 yr B.P.
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Patra, B. P., and N. K. Sahoo. "Some observations on the occurrence of Cycadophytes and Bennettitales in the East Coast Upper Gondwana Athgarh Sandstone, Cuttack and Khurda districts of Orissa, India." Journal of Palaeosciences 44 (December 31, 1995): 139–51. http://dx.doi.org/10.54991/jop.1995.1205.
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Athgarh Sandstone is rich in plant megafossils, in which the pteridophytes and conifers are dominated followed by Bennettitales and Cycadophytes. The species described in this paper are: Ptilophyllum acutifolium, Ptilophyllum spp., Pterophyllum kingianum, Pterophyllum sp. cf. P. distans, Otozamites penna, Otozamites sp. cf. O. kachchhensis, Anomozamites fissus, Dictyozamites sp. and Taeniopteris spatulata. A comparison of this assemblage with similar other assemblages from the Lower Cretaceous of India has also been made.
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Staude, Hermann S., Marion Maclean, Silvia Mecenero, Rudolph J. Pretorius, Rolf G. Oberprieler, Simon Van Noort, Allison Sharp, et al. "Noctuoidea: Noctuidae: Caradrinine assemblage." Metamorphosis 31, no. 3 (March 23, 2022): 235–43. http://dx.doi.org/10.4314/met.v31i3.16.
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EXPLANATION OF THE MASTER LISTSThere are 28 master lists, grouped as convenient taxon groups and split in such a way as to make each list individually downloadable but form an integral part of the main article. Citations to these master lists should be as indicated for the main article. Each master list contains a table that is made up of eight columns and each row represents information on one rearing record. For each master list, the rearing records are ordered under family, subfamily and sometimes tribe headings (in some cases we offer a superfamily instead of a family name where we were uncertain of the family placement). The records are ordered by family, subfamily, species and then rearer name. Explanation of the information contained in each column is as follows:Ref. no. This column contains references to a unique rearing number that links the notes, photographs and reared specimens gathered during the course of the rearing. A blank field indicate that there was no reference number submitted.Lepidoptera species. This column contains the best identification that could be made of the Lepidoptera taxon at the time of publication given the resources available. The name of the taxon specialist who identified the species (if not an author) is given in brackets. A blank cell means that we were unable to identify the taxon with some certainty.Host species (Family). This columns contain the best identifications that could be made of the host species, on which the caterpillar was feeding, at the time of publication given the resources available. A blank cell means that we were unable to identify the plant species to that level with some certainty or that feeding by the caterpillar was not confirmed. In the majority of cases the host indicated is the host on which the life stage was collected in the wild and on which the caterpillar fed subsequently. In cases where the host was presented to the larva in captivity, this is indicated. Where relevant, the name of the determiner is given in brackets. The host family name is given at the end in brackets. The phrase “reared ab ovum” means that the pictured larva was reared from the egg, meaning that the entire life-history of the species (all larval instars) was recorded and documented. In most cases such larvae were reared from eggs laid by a female moth collected at a light but raised on a natural host-plant of the species (though not necessarily one occurring at the locality where the female was taken), in some cases such larvae were reared from eggs found laid on a host-plant in the wild, and in a few cases the larvae were reared on an unnatural (exotic) host-plant in captivity. Such imprecisions regarding host use are, however, also contained in records of field-collected larvae, as mature larvae sometimes feed on plants they will not take in the early instars but do switch to at a later stage, and many also naturally feed on exotic plants in the wild.Locality. This column contains a short standardised reference to the locality where the specimen used in the rearing was collected, be it any life stage or a female from which eggs were obtained. The locality field lists, in order, the locality description, followed by the closest town, province (where relevant) and then country.Date of collection (c), pupation (p), emergence (e). This column contains the dates as indicated, where available. Missing dates are indicated by a “?”.Rearer. This column contains the name(s) of the person(s) who conducted the rearing, who may or may not have been the person who collected the rearing material.Final instar larva. This column contains the photographs of the caterpillar of the species reared. In most cases they depict the final-instar larva and at the time it was still feeding, but in some cases they show the larva in the pre-pupation phase (usually on the ground) and in a few cases an earlier instar, where for some reason a photograph of the final instar was unavailable.Adult. This column contains photographs of the actual adult specimen reared from the caterpillar shown in the previous column. Photographs marked with * are not of the actual adult specimen which emerged from the imaged larva.
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Kvaček, Zlatko, Vasilis Teodoridis, Marianna Kováčová, Ján Schlögl, and Viliam Sitár. "Lower Miocene plant assemblage with coastal-marsh herbaceous monocots from the Vienna Basin (Slovakia)." Geologica Carpathica 65, no. 3 (June 1, 2014): 229–41. http://dx.doi.org/10.2478/geoca-2014-0016.
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Abstract A new plant assemblage of Cerová-Lieskové from Lower Miocene (Karpatian) deposits in the Vienna Basin (western Slovakia) is preserved in a relatively deep, upper-slope marine environment. Depositional conditions with high sedimentation rates allowed exceptional preservation of plant remains. The plant assemblage consists of (1) conifers represented by foliage of Pinus hepios and Tetraclinis salicornioides, a seed cone of Pinus cf. ornata, and by pollen of the Cupressaceae, Pinaceae, Pinus sp. and Cathaya sp., and (2) angiosperms represented by Cinnamomum polymorphum, Platanus neptuni, Potamogeton sp. and lauroid foliage, by pollen of Liquidambar sp., Engelhardia sp. and Craigia sp., and in particular by infructescences (so far interpreted as belonging to cereal ears). We validate genus and species assignments of the infructescences: they belong to Palaeotriticum Sitár, including P. mockii Sitár and P. carpaticum Sitár, and probably represent herbaceous monocots that inhabited coastal marshes, similar to the living grass Spartina. Similar infructescences occur in the Lower and Middle Miocene deposits of the Carpathian Foredeep (Slup in Moravia), Tunjice Hills (Žale in Slovenia), and probably also in the Swiss Molasse (Lausanne). This plant assemblage demonstrates that the paleovegetation was represented by evergreen woodland with pines and grasses in undergrowth, similar to vegetation inhabiting coastal brackish marshes today. It also indicates subtropical climatic conditions in the Vienna Basin (central Paratethys), similar to those implied by other coeval plant assemblages from Central Europe
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Fernandes, Izaias M., Francisco A. Machado, and Jerry Penha. "Spatial pattern of a fish assemblage in a seasonal tropical wetland: effects of habitat, herbaceous plant biomass, water depth, and distance from species sources." Neotropical Ichthyology 8, no. 2 (2010): 289–98. http://dx.doi.org/10.1590/s1679-62252010000200007.
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The influence of habitat, biomass of herbaceous vegetation, depth and distance from permanent water bodies on the structure of fish assemblages of a seasonal floodplain was evaluated using data collected along 22 transects in an area of 25 km² in the floodplain of Cuiabá River, Pantanal, Brazil. Each transect was sampled for fish using throw traps and gillnets during the flood period of 2006. Multivariate multiple regression analysis and multivariate analysis of covariance indicated that depth was the only variable that affected the structure of the fish assemblage, both for quantitative data (abundance) and qualitative data (presence-absence). Species such as Neofundulus parvipinnis and Laetacara dorsigera were more abundant in shallower sites (below 25 cm), while Serrasalmus maculatus and Metynnis mola were found mostly in the deepest areas (over 55 cm). However, species such as Hoplias malabaricus and Hoplerythrinus unitaeniatus occurred at all sampled depths. Although the distribution of most species was restricted to a few sites, there was a positive relationship between species richness and depth of the water body. Surprisingly, the replacement of native vegetation by exotic pasture did not affect the fish assemblage in the area, at the probability level considered.
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Laborde, Anita, Evelyn Habit, and Oscar Link. "Hydropower dams threaten freshwater Chilean fish species: What dams and what species?" E3S Web of Conferences 40 (2018): 03032. http://dx.doi.org/10.1051/e3sconf/20184003032.
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Hydropower is experiencing a development boom worldwide. However, at the same time, challenge sustainability, mainly due to synergistic effects of several projects in the species distribution area. What and how hydroelectric projects will affect species, depends on a number of attributes. We analysed Chilean freshwater species distributed over 10 major basins of Central Chile threaten by 1124 plants (12,338 GW) planned in a hotspot of biodiversity. The exposure of the species to the planned hydropower projects was analyzed at the scale of species and as an assemblage. The hazardousness was evaluated by type, according to characteristics of planned hydropower plant: size, dam height and turbine type. Finally, considering species and assemblage exposition the most threaten genera were defined. Project analysed compile 45% of the exploitable potential, with a total of 198 (75.5%) project with capacities < 20MW, and 280 (88.1%) with low head dams (<20 m). 22.6% of the species are not exposed to planned plants, 54.8% are exposed to a small number of plants (<5), and 22.6% are frequently exposed to plants (> 60). The latter species pertain to genera Trichomycterus, Percilia, and Diplomystes, defining a critical fish assemblage that facilitates the management of an important part of the cases (40.4%) through mitigation technologies.
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Gama-Matos, Rayanne, Átilla Colombo Ferreguetti, Giulia Mekiassen do Nascimento, Juliane Pereira-Ribeiro, Natália Vagmaker, Alex Júnior Boazi, Walker Dantas Isidoro Grisóstomo, Carlos Frederico Duarte Rocha, and Helena Godoy Bergallo. "Can an exotic tree (Jackfruit, Artocarpus heterophyllus Lam.) influence the non-volant small mammals assemblage in a protected area of Atlantic Forest?" Journal of Tropical Ecology 36, no. 5 (September 2020): 243–50. http://dx.doi.org/10.1017/s026646742000019x.
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AbstractJackfruit (Artocarpus heterophyllus Lam.) is an exotic invasive plant species in the Brazilian Atlantic Forest that causes changes in the environment through the release of allelopathic substances and has high fruit production. We aimed to understand the potential effects of the jackfruit on the non-volant small mammal assemblage in an area protected by law, in the municipality of Cariacica – Espírito Santo, south-eastern Brazil. We sampled the small mammals assemblage using live traps in 18 sites, eight with jackfruit and 10 without. We ordinated the assemblage and tested possible differences in species richness and abundance according to the jackfruit density. We recorded 31 species of non-volant small mammals, with 13 species endemic to the Atlantic Forest. Jackfruit species can affect both positively and negatively the studied assemblage of non-volant small mammals. For species with a frugivory habit, jackfruit has a positive effect favouring these species. On the other hand, for insectivorous species, jackfruit represents an impact inhibiting the presence of these species in an area with high jackfruit density. The results presented are the first step in understanding the effect of this invasive species on a small mammals assemblage and initiating a monitoring of these species in areas affected by jackfruits. Furthermore, management of jackfruits in this protected area is required.
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Field, Michael H. "Identification of a population of Ranunculus achenes extracted from Middle Pleistocene sediments exposed at Belhus Park, Essex, UK." Acta Palaeobotanica 53, no. 2 (December 1, 2013): 181–89. http://dx.doi.org/10.2478/acpa-2013-0011.
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ABSTRACT A plant macrofossil assemblage extracted from Middle Pleistocene fluvial organic sediments collected from Belhus Park, Aveley, Essex, UK contained a number of tuberculate (verrucose) achenes attributed to the genus Ranunculus, one of which had two short spines preserved on its surface. The identification of these achenes is discussed here. This is worthy of note because Ranunculus tuberculate or spinose fossil achenes can be difficult to determine to species as they can have similar features, some Ranunculus species produce achenes in several morphological forms, and during fossilization delicate structures maybe destroyed (e.g. spines). After careful morphological consideration it is concluded that the fossil achenes from Belhus Park are Ranunculus parviflorus L., indicating that dry grassland or disturbed ground existed in the river catchment. The plant macrofossil assemblages that included the Ranunculus parviflorus achenes were dominated by waterside, damp ground, and aquatic taxa. It is probable that flowing water transported the achenes from further afield before their incorporation into the fluvial sediments. The identification of these fossils illustrates the importance of considering the morphological characteristics of the achene only and not to make a determination on the nature of the predominant palaeoenvironmental signal from an assemblage.
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Agnihotri, Deepa, Rajni Tewari, S. Suresh Kumar Pillai, Andre Jasper, and Dieter Uhl. "Early Permian Glossopteris flora from the Sharda Open Cast Mine, Sohagpur Coalfield, Shahdol District, Madhya Pradesh." Journal of Palaeosciences 65, no. (1-2) (December 31, 2016): 97–107. http://dx.doi.org/10.54991/jop.2016.302.
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Well preserved plant fossil assemblage recorded for the first time from the Barakar Formation of Sharda Open Cast Mine, Sohagpur Coalfield, Shahdol District, Madhya Pradesh is documented in this study. The assemblage comprises the orders Equisetales, Glossopteridales and Cordaitales. Equisetales is represented by unidentifiable leafless equisetalean axes bearing nodes and internodes, Glossopteridales comprises one species of Gangamopteris (Gangamopteris intermedia) and seven species of Glossopteris (Glossopteris communis, G. gigas, G. giridihensis, G. indica, G. longicaulis, G. spatulata and Glossopteris sp.), and Cordaitales is known by one species of Noeggerathiopsis (Noeggerathiopsis hislopii). The floral assemblage is broadly comparable with those described previously from the Barakar Formation of Damodar, Mahanadi, Wardha, Godavari, Rajmahal and Satpura Gondwana basins of India. Since the known records of plant mega fossils from the Barakar Formation of Sohagpur Coalfield are meagre, recovery of quantitatively and qualitatively rich plant fossils from the Sharda Open Cast Mine substantiates the geological and geographical distribution of the Glossopteris flora in India in general and that of the Sohagpur Coalfield in particular, and reflects its significance in the formation of coal in the area.
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Salvo, A., and G. Valladares. "Parasitoid assemblage size and host ranges in a parasitoid (Hymenoptera)–agromyzid (Diptera) system from central Argentina." Bulletin of Entomological Research 89, no. 2 (February 1999): 193–97. http://dx.doi.org/10.1017/s0007485399000280.
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AbstractA parasitoid community on agromyzid leafminers from Cordoba, Argentina was analysed in terms of parasitoid assemblage size and host ranges of parasitoid species. Samples were taken during 1991–1995 at natural, urban and agricultural habitats. The system consisted of 69 parasitoid species and 51 leafminer species on 109 plant species. On average, 12 species parasitized each host, when only numerically well represented leafminer species were considered for analysis. Each parasitoid species exploited on average seven species and three genera of agromyzid leafminers. Both parasitoid assemblage size and parasitoid host range were notably high when compared with similar systems from other regions.
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Tewari, Rajni, and A. K. Srivastava. "Plant fossil assemblage from the talchir formation, Auranga coalfield, Bihar, India." Journal of Palaeosciences 49, no. (1-3) (December 31, 2000): 23–30. http://dx.doi.org/10.54991/jop.2000.129.
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Investigations on the Talchir sediments of Auranga Coalfield have yielded well preserved plant fossils from Jaitri river section situated about 1·5 km northeast of Latehar town of Palamau District, Bihar. The assemblage is represented by the species of Gangamopteris (G. cyclopteroides, G. fibrosa, G. clarkeana, G. major; G. angustifolia, G. karharbariensis, Gangamopteris sp.) and Glossopteris (G. talchirensis, G. indica, G. communis, G. stenoneura, G. tenuifolia, G. spatulala) besides a number of scale leaves and equisetalean-stem axes. The known records of plant fossils from the Talchir Formation indicate dominance of Gangamopteris leaves (10 sp.) whereas, Glossopteris leaves are recorded by only two species. The present report of occurrence of six species of Glossopteris and seven species of Gangamopteris demonstrates simultaneous settlement and diversification 0f the two types of glossopterid leaves i.e., midrib-less forms of Gangamopteris and midrib possessing forms of Glossopteris, during the early phase (The Talchir Formation) of Glossopteris flora.
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Chung, A. Y. C., P. Eggleton, M. R. Speight, P. M. Hammond, and V. K. Chey. "The diversity of beetle assemblages in different habitat types in Sabah, Malaysia." Bulletin of Entomological Research 90, no. 6 (December 2000): 475–96. http://dx.doi.org/10.1017/s0007485300000602.
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AbstractThe diversity of beetle assemblages in different habitat types (primary forest, logged forest, acacia plantation and oil palm plantation) in Sabah, Malaysia was investigated using three different methods based on habitat levels (Winkler sampling, flight-interception-trapping and mist-blowing). The overall diversity was extremely high, with 1711 species recorded from only 8028 individuals and 81 families (115 family and subfamily groups). Different degrees of environmental changes had varying effects on the beetle species richness and abundance, with oil palm plantation assemblage being most severely affected, followed by acacia plantation and then logged forest. A few species became numerically dominant in the oil palm plantation. In terms of beetle species composition, the acacia fauna showed much similarity with the logged forest fauna, and the oil palm fauna was very different from the rest. The effects of environmental variables (number of plant species, sapling and tree densities, amount of leaf litter, ground cover, canopy cover, soil pH and compaction) on the beetle assemblage were also investigated. Leaf litter correlated with species richness, abundance and composition of subterranean beetles. Plant species richness, tree and sapling densities correlated with species richness, abundance and composition of understorey beetles while ground cover correlated only with the species richness and abundance of these beetles. Canopy cover correlated only with arboreal beetles. In trophic structure, predators represented more than 40% of the species and individuals. Environmental changes affected the trophic structure with proportionally more herbivores (abundance) but fewer predators (species richness and abundance) in the oil palm plantation. Biodiversity, conservation and practical aspects of pest management were also highlighted in this study.
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Mulholland, Susan C., George Rapp Jr., Amy L. Ollendorf, and Ronald Regal. "Variation in phytolith assemblages within a population of corn (cv. Mandan Yellow Flour)." Canadian Journal of Botany 68, no. 8 (August 1, 1990): 1638–45. http://dx.doi.org/10.1139/b90-210.
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This project investigates the effects of leaf side, leaf position, individual plant, and hill (or plant group) on phytolith assemblages from Zea mays L. cultivar Mandan Yellow Flour. Thirty-two samples were examined, and 200 phytoliths were classified from each sample. Statistical analysis indicates that leaf side is significant at the 0.05 level above random counting variation; leaf position, individual plant, and hill are not generally significant beyond the effect of leaf side. Analysis of a single sample, either a half or entire leaf, is not sufficient for compilation of representative phytolith assemblages from a plant population. Phytolith reference collections should not be based on single samples of each species. Multiple samples from a population need to be analyzed to obtain information on assemblage variation within the population. The variation of corn phytolith assemblages in this study overlaps those of many Panicoid grasses, indicating that additional morphological characters need to be identified to distinguish corn from wild grasses in the Great Plains. Key words: phytoliths, corn, frequencies, variation.
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Guerin, Greg R., and Robert S. Hill. "Plant macrofossil evidence for the environment associated with the Riversleigh fauna." Australian Journal of Botany 54, no. 8 (2006): 717. http://dx.doi.org/10.1071/bt04220.
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Fossil plant organs from probable Oligocene nodules at the Dunsinane Site at Riversleigh, Queensland, were studied. The deposit consists of a low diversity assemblage of reproductive and vegetative organs dominated by a single taxon of Casuarinaceae. The species of Casuarinaceae has affinities with Casuarina and Allocasuarina in having more four teeth per whorl on the photosynthetic branchlets and stomata hidden in deep furrows filled with trichomes, and as such represents the earliest known record of sub-family Cryptostomae. The species is described as Cryptostomiforma quinata gen. et sp. nov. A leaf species is assigned to Alectryon (Sapindaceae) on the basis of the anatomy of abaxial cuticular features. In particular, the morphology is indistinguishable from extant A. affinis, a species currently endemic to New Guinea. Organs with possible affinities to Rubus or Capparis were examined. The assemblage is interpreted as a possible vegetation mosaic, containing both deciduous vine thickets and sclerophyllous habitats. No evidence for the presence of rainforest was found and the fossils are not consistent with extensive lowland tropical rainforest.
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Osnas, Jeanne L. D., Masatoshi Katabuchi, Kaoru Kitajima, S. Joseph Wright, Peter B. Reich, Sunshine A. Van Bael, Nathan J. B. Kraft, Mirna J. Samaniego, Stephen W. Pacala, and Jeremy W. Lichstein. "Divergent drivers of leaf trait variation within species, among species, and among functional groups." Proceedings of the National Academy of Sciences 115, no. 21 (May 3, 2018): 5480–85. http://dx.doi.org/10.1073/pnas.1803989115.
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Understanding variation in leaf functional traits—including rates of photosynthesis and respiration and concentrations of nitrogen and phosphorus—is a fundamental challenge in plant ecophysiology. When expressed per unit leaf area, these traits typically increase with leaf mass per area (LMA) within species but are roughly independent of LMA across the global flora. LMA is determined by mass components with different biological functions, including photosynthetic mass that largely determines metabolic rates and contains most nitrogen and phosphorus, and structural mass that affects toughness and leaf lifespan (LL). A possible explanation for the contrasting trait relationships is that most LMA variation within species is associated with variation in photosynthetic mass, whereas most LMA variation across the global flora is associated with variation in structural mass. This hypothesis leads to the predictions that (i) gas exchange rates and nutrient concentrations per unit leaf area should increase strongly with LMA across species assemblages with low LL variance but should increase weakly with LMA across species assemblages with high LL variance and that (ii) controlling for LL variation should increase the strength of the above LMA relationships. We present analyses of intra- and interspecific trait variation from three tropical forest sites and interspecific analyses within functional groups in a global dataset that are consistent with the above predictions. Our analysis suggests that the qualitatively different trait relationships exhibited by different leaf assemblages can be understood by considering the degree to which photosynthetic and structural mass components contribute to LMA variation in a given assemblage.
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Fagundes, Roberth, Kleber Del-Claro, and Sérvio Pontes Ribeiro. "Effects of the Trophobiont HerbivoreCalloconophora pugionata(Hemiptera) on Ant Fauna Associated withMyrcia obovata(Myrtaceae) in a Montane Tropical Forest." Psyche: A Journal of Entomology 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/783945.
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Many studies have investigated the mechanisms behind the structure of arboreal ant assemblages. In this study, the objective was to evaluate the effect of availability of honeydew-producing colonies ofCalloconophora pugionata(Membracidae) on the structure of ant assemblages associated with the host plantMyrcia obovata(Myrtaceae) in an Atlantic forest of Minas Gerais (Brazil). Our experiment consisted in a gradual exclusion of hemipteran colonies out of the host plant crown and further record of the ant assemblage response (species richness, composition, and occurrence) to the presence and density of treehopper colonies. The hypothesis was that an increase in the number of trophobiont herbivores results in an increase in tending ant occurrence but a reduction in ant species diversity. Results corroborated our main hypothesis: membracids had a positive effect on the occurrence of ants but negative on species richness. Overall insect occurrence was also reduced with increasing inC. pugionatacolonies, probably due to strengthening dominant ant species territory sizes and intensification of patrolling.
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Datar, Mandar N., and Aparna V. Watve. "Vascular plant assemblage of cliffs in northern Western Ghats, India." Journal of Threatened Taxa 10, no. 2 (February 26, 2018): 11271. http://dx.doi.org/10.11609/jott.3611.10.2.11271-11284.
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Vertical rocky cliffs, which consist of various types of rock, are widespread all over the world. India’s northern Western Ghats consisting of basaltic rocks form probably the largest cliff ecosystem globally, however, almost no studies are available concerning their floristic richness. In an attempt to understand the vascular plant assemblage of this habitat, cliffs of the northern Western Ghats were surveyed for their microhabitats, species diversity, distribution of endemics, occurrence of particular adaptive traits and potential threats. A total of 102 species of vascular plants were documented from the cliff habitats of which 55 are endemic. Flowering of the species on cliffs is triggered by the advent of the south-west monsoon and peak flowering is seen between August and October. Of the total species, 27 grow exclusively on cliffs. Owing to habitat specificity, cliffs show a greater number of narrow endemic and threatened species when compared with other habitats like deciduous, evergreen and semi-evergreen forests, which are widespread in the northern Western Ghats. Unfortunately, this habitat faces threats in the form of landslides, periodic burning and habitat loss due to road-widening.
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Dong, Ke, Cheolwoon Woo, and Naomichi Yamamoto. "Plant assemblages in atmospheric deposition." Atmospheric Chemistry and Physics 19, no. 18 (September 25, 2019): 11969–83. http://dx.doi.org/10.5194/acp-19-11969-2019.
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Abstract. Plants disperse spores, pollen, and fragments into the atmosphere. The emitted plant particles return to the pedosphere by sedimentation (dry deposition) and/or by precipitation (wet deposition) and constitute part of the global cycle of substances. However, little is known regarding the taxonomic diversities and flux densities of plant particles deposited from the atmosphere. Here, plant assemblages were examined in atmospheric deposits collected in Seoul in South Korea. A custom-made automatic sampler was used to collect dry and wet deposition samples for which plant assemblages and quantities were determined using high-throughput sequencing and quantitative polymerase chain reaction (PCR) with universal plant-specific primers targeting the internal transcribed spacer 2 (ITS2) region. Dry deposition was dominant for atmospheric deposition of plant particles (87 %). The remaining 13 % was deposited by precipitation, i.e., wet deposition, via rainout (in-cloud scavenging) and/or washout (below-cloud scavenging). Plant assemblage structures did not differ significantly between dry and wet deposition, indicating a possibility that washout, which is possibly taxon-independent, predominated rainout, which is possibly taxon-dependent, for wet deposition of atmospheric plant particles. A small number of plant genera were detected only in wet deposition, indicating that they might be specifically involved in precipitation through acting as nucleation sites in the atmosphere. Future interannual monitoring will control for the seasonality of atmospheric plant assemblages observed at our sampling site. Future global monitoring is also proposed to investigate geographical differences and investigate whether endemic species are involved in plant-mediated bioprecipitation in regional ecological systems.
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Janda, Milan, and Martina Konečná. "Canopy assemblages of ants in a New Guinea rain forest." Journal of Tropical Ecology 27, no. 1 (December 17, 2010): 83–91. http://dx.doi.org/10.1017/s0266467410000623.
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Abstract:The ant assemblages in two common tree species in primary lowland forest of New Guinea were explored using direct canopy access and tuna bait traps. The 19 trees investigated were occupied by 21 ant species of which 18 were canopy inhabitants. On average only 3.6 ant species per tree and 3 species per bait were found. Height of bait position was positively related to ant species richness, with the upper parts of the canopy being occupied by the highest number of species. On the other hand, tree species and study site did not have any effect on ant species richness nor on structure of the ant assemblages. Ant species appeared to be distributed randomly and we did not detect any effect of distance on similarity of ant assemblage occurring on the trees. The dominant species (Crematogaster polita) had certain negative effects on the presence of some species at food sources co-occurring at the same tree, but it did co-occur with the other ants to some extent as well. The majority of species found in the canopy were generalist omnivores (depending mainly on trophobionts or plant exudates).
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Silva, Paulo S. D., Inara R. Leal, Rainer Wirth, Felipe P. L. Melo, and Marcelo Tabarelli. "Leaf-cutting ants alter seedling assemblages across second-growth stands of Brazilian Atlantic forest." Journal of Tropical Ecology 28, no. 4 (June 1, 2012): 361–68. http://dx.doi.org/10.1017/s0266467412000259.
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Abstract:Secondary forests promote an increased abundance of leaf-cutting ants (LCA) but the consequences on forest dynamics have been poorly addressed. Here we examine seedling assemblage attributes, seed germination and seedling survival across foraging zones of Atta cephalotes colonies inhabiting 15 second-growth patches (25–47 y old) of Atlantic forest. Seeds and seedlings were monitored within foraging zones and control sites over 1 y, including spots around ant nests. Overall, 1862 seedlings from 108 plant species were recorded. Seedling density decreased by 53% in foraging-zone plots (3.31 ± 0.23 seedlings m−2) when compared with control plots (7.02 ± 0.44 seedlings m−2) and a similar decrease was observed for species richness. Ant-induced alterations in the seedling assemblage were further indicated by segregation between foraging-zone and control plots (NMDS), habitat effects on species similarity (ANOSIM), and indicator tree species associated with control plots. While seed germination and seedling survivorship were uncorrelated to either nest distance or age of second-growth stands (with the exception of Tapirira guianensis), defoliation by LCAs was a significant cause of seedling mortality. Our results suggest that LCAs interfere with successional trajectories of Atlantic forest as foraging zones filter seedling establishment, supporting less-dense, impoverished and convergent seedling assemblages.
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Choi, Sung-Kook, Kyungsik Kim, Eun-Kyoung Jeong, Kazuo Terada, Mitsuo Suzuki, and Houhei Uematsu. "Fossil Woods from the Miocene in the Yamagata Prefecture, Japan." IAWA Journal 31, no. 1 (2010): 95–117. http://dx.doi.org/10.1163/22941932-90000009.
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Eighty-two silicified fossil woods were collected from Miocene formations on the western coast of the Yamagata Prefecture, Japan. Twenty-two taxa (5 conifers and 17 dicotyledons) were identified. Five new species (Chamaecyparis parathyoides, Pterocarya parvipora, Populus soyaensis, Schima protowallichii, Lagerstroemia odaniense) and two species not previously known from the Miocene of Yamagata are described. This brings the number of fossil wood taxa from the Miocene of Yamagata to 39. Warm temperate elements such as Keteleeria, Liquidambar, Distylium and Lagerstroemia were found in the formations studied. The fossil wood assemblages from four Miocene formations (except Onisakatoge Formation from which only one sample was collected) suggest that the woody flora changed gradually during the Miocene from a mixture of cool and warm temperate elements to a warm temperate assemblage. These changes agree well with the vegetation changes during the Miocene in Japan; from the Aniai type to the Daijima-type.
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Tuya, Fernando, and Ricardo J. Haroun. "Phytogeography ofLusitanianMacaronesia: biogeographic affinities in species richness and assemblage composition." European Journal of Phycology 44, no. 3 (August 2009): 405–13. http://dx.doi.org/10.1080/09670260902836246.
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Karasov-Olson, Aviv, and Douglas A. Kelt. "Small mammal assemblage composition and habitat associations across an elevational gradient in southern California." Journal of Mammalogy 101, no. 1 (December 13, 2019): 92–106. http://dx.doi.org/10.1093/jmammal/gyz178.
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Abstract Elevational gradients coincide with expansive climatic gradients and diverse plant and animal communities. We evaluated the small mammal assemblages in eight distinct vegetation types across an elevational gradient in southern California, the Deep Canyon Transect, to determine how assemblage composition changes across the gradient and to identify species with similar habitat associations. Livetrapping efforts (4,800 trap-nights) yielded 1,097 captures of 713 individuals, representing 14 heteromyid and cricetid species. Heteromyids dominated the six lower-elevation vegetation types (< 1,300 m a.s.l.), whereas cricetids dominated the upper end of the gradient. Richness and diversity exhibited bimodal responses to elevation, which do not conform to mid-domain effect null predictions. Canonical correspondence analysis revealed that 75% of the variation in small mammal abundances was explainable by habitat characteristics, and cluster analysis grouped small mammals into three ecologically distinct groups based on their habitat associations. One contained only Chaetodipus penicillatus, while the others were comprised of low- and high-elevation species, respectively. The low-elevation species exhibit unusual levels of sympatry (and syntopy) among closely related species of pocket mice (Chaetodipus). Further efforts should investigate the mechanisms of coexistence for Chaetodipus species with nearly identical associations and seasonal effects on richness and diversity. Repeated surveys of entire gradients such as the Deep Canyon Transect will help refine our understanding of temporal dynamics of community assemblage and diversity.
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Korotyaev, Boris A., Levent Gültekin, Mark G. Volkovitsh, Vladimir I. Dorofeyev, and Alexander S. Konstantinov. "Bioindicator beetles and plants in desertified and eroded lands in Turkey." Journal of Insect Biodiversity 4, no. 1 (January 1, 2016): 1. http://dx.doi.org/10.12976/jib/2016.4.1.
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The xerophilous vegetation with characteristic insect assemblages is described in the main agricultural regions and native landscapes of Turkey. Long term intensive investigations documented vast biotic degradation of soil and vegetation (commonly referred to as desertification) by overgrazing, construction, recreation etc. Two main types of xeric landscape are under investigation: 1) natural highly specific deserts, semi-deserts, dry mountain slopes and screes; and 2) anthropogenic, newly emerged, floristically impoverished desertified areas. The presence of a multi-species insect assemblage on a xerophilous plant in certain area testifies its indigenous nature, whereas the absence of the specific consortium suggests recent plant invasion. The examples of the first case are the consortia of 3–6 species of Coleoptera, mainly Buprestidae, Chrysomelidae, and Curculionoidea, on some Apiaceae, Asteraceae, Brassicaceae, Chenopodiaceae, Ephedraceae (Ephedra spp.) and Polygonaceae (Calligonum polygonoides L.). Extreme examples of anthropogenic vegetation are overgrazed wormwood steppe and semidesert which lack usually diversified coleopterous consortia, including the most characteristic of this landscape, e.g., tenebrionids, and orthopterans. Rapid disappearance of the xerophilous complexes from the extraordinarily diversified and largely uninventoried Turkish biota makes preservation of the endangered plant and animal assemblages in different climatic zones of Turkey an urgent task.
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Dartnell, Sofia, Andre R. O. Cavalcanti, Ayame Misaki Bluebell, Nancy V. Hamlett, Edward J. Crane, and Wallace M. Meyer. "Flower-Visiting Insect Assemblages on Fall-Blooming Native California Sage Scrub Shrubs." Diversity 14, no. 11 (November 9, 2022): 958. http://dx.doi.org/10.3390/d14110958.
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Pollinator studies in the endangered California sage scrub ecosystem have focused on spring insect assemblages, when most plant species bloom. Consequently, the insect assemblages using common fall-blooming sage scrub shrubs Lepidospartum squamatum, Ericameria pinifolia, and Baccharis pilularis remain undescribed. Our study aimed to: (1) document flower-visiting insect assemblages on fall-blooming shrubs, (2) assess the efficacy of three sampling techniques in inventorying insect assemblages, and (3) explore, using DNA metabarcoding, which plants are utilized and the extent to which surrounding suburban habitats’ plants are also used. While elevated sampling is required to inventory flower-visiting insects, we describe a diverse assemblage consisting of 123 species. Insect assemblages differed between L. squamatum and B. pilularis, as well as, E. pinifolia and B. pilularis, but not between L. squamatum and E. pinifolia. Direct sampling approaches (netting and photo documentation) collected 115 species not collected by passive malaise traps, highlighting that active observations are required to describe flower-visiting insect assemblages. Sequencing the ITS2 region of pollen from abundant visitors revealed that a majority of pollen is from the sage scrub ecosystem, highlighting its value. Our results indicate that the presence of fall-blooming shrubs may be critical for maintaining diverse sage scrub insect and pollinator assemblages.
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Lee, Philip, and Kelly Sturgess. "The effects of logs, stumps, and root throws on understory communities within 28-year-old aspen-dominated boreal forests." Canadian Journal of Botany 79, no. 8 (August 1, 2001): 905–16. http://dx.doi.org/10.1139/b01-072.
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This study examined the role of logs, stumps, and root throws on the understory composition of aspen-dominated boreal forests. Measures of microsite coverage and suitability, and vascular plant composition and abundance were taken from 28-year-old wildfire and harvest sites. Larger logs (>20 cm diameter) with soft surfaces were the most suitable for colonization by vascular plants. These logs covered more than five times the area of stumps or root throws in both harvest and wildfire sites. Detrended correspondence analysis revealed that logs and stumps were colonized by a significantly different assemblage of vascular plants than the forest floor of either disturbance type. Contrary to studies in other forest types, assemblages of plants on root throw pits and mounds were similar to those on the forest floor. Initial colonization patterns on logs and stumps in both wildfire and harvest sites were similar. However, on more decayed logs assemblages of vascular plants were more similar to their respective wildfire or harvest forest floor assemblages. Ordination of species suggested that tree seedlings and shade-tolerant herbs were disproportionately more abundant on logs and stumps.Key words: plant community assemblages, deadwood resources, coarse woody debris, root throws, logs, boreal forest.
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Heřmanová, Zuzana, Jiří Kvaček, and Else Marie Friis. "Plant mesofossils from the Late Cretaceous Klikov Formation, the Czech Republic." Fossil Imprint 77, no. 2 (2021): 256–70. http://dx.doi.org/10.37520/fi.2021.018.
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Late Cretaceous mesofossils are described from the Zliv-Řídká Blana locality in the South Bohemian Basins, the Czech Republic. Angiosperm remains dominate the fossil assemblage both in terms of taxonomic diversity and quantitatively, with about 65 different species based on about 1,000 specimens of flowers, fruits and seeds. There are surprisingly few nonangiosperm species in the flora, with only four specimens assigned to bryophytes, ferns and conifers. There are no megaspores of Selaginellales or Salviniales, which are otherwise common in many Cretaceous mesofossil floras. Among angiosperms, flowers and fruits assigned to the Normapolles group (Fagales) and to the Ericales are particularly prominent. In systematic composition as well as general organization and size of the angiosperm reproductive organs, the Zliv-Řídká Blana mesofossil flora is comparable to other Late Cretaceous mesofossil floras collected from various regions of Laurasia. In addition to the plant remains, the fossil assemblage also includes insect eggs and coprolites.
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Hargan, Kathryn E., Kathleen M. Rühland, Andrew M. Paterson, Sarah A. Finkelstein, James R. Holmquist, Glen M. MacDonald, Wendel Keller, and John P. Smol. "The influence of water-table depth and pH on the spatial distribution of diatom species in peatlands of the Boreal Shield and Hudson Plains, Canada." Botany 93, no. 2 (February 2015): 57–74. http://dx.doi.org/10.1139/cjb-2014-0138.
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Diatoms collected from 113 surface peat samples from the Boreal Shield and Hudson Plains show taxonomic distributions that are associated with macro-vegetation type, pH, and position relative to the water table, the main environmental variables measured in this study. The overall goal of our research was to determine the ecological distribution and response of diatoms to microhabitat conditions, and to assess the potential for diatoms to be applied as indicators of long-term environmental change in northern peatlands. Our results indicate that diatom assemblage composition was determined by both the broader peatland type (i.e., bog, rich and poor fens) and microhabitats within peatland formations (e.g., hummock, hollow). The diatom assemblages were primarily influenced by pH with the sites divided at a critical pH of 5.5, and secondarily by the depth to the water table. Acidic bog hollow and hummock microhabitats were species-poor and dominated almost exclusively by Eunotia paludosa A.Grunow and (or) Eunotia mucophila (H.Lange-Bertalot, M.Nörpel-Schempp & E.Alles) H.Lange-Bertalot. These acidophilic and aerophilic diatom species were associated with the narrow pH optima of the dominant Sphagnum L. species (e.g., Sphagnum fuscum (Schimp.) Klinggr., Sphagnum angustifolium (C.E.O.Jensen ex Russow) C.E.O.Jensen) found in these bog habitats. Rich and poor fen samples, which were less acidic, supported a more diverse diatom assemblage (>30 species) with greater variability in both diatom and bryophyte pH tolerances. The diatom assemblages recorded in the bogs and fens of our study are similar to those found in peatlands around the world, demonstrating that diatom species are very specialized to exist in these often harsh semi-aquatic environments. Diatoms from peatlands have great potential as biomonitors of environmental change in these important ecosystems.