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1
Liu, Q., P. Loganathan, M. J. Hedley e M. F. Skinner. "Root processes influencing phosphorus availability in volcanic soils under young Pinus radiata plantations". Canadian Journal of Forest Research 36, n. 8 (1 agosto 2006): 1913–20. http://dx.doi.org/10.1139/x06-083.
Testo completoAbstract (sommario):
Phosphorus (P) availability was investigated in rhizosphere soils under 4- to 5-year-old, second-rotation Pinus radiata D. Don and understorey grass (browntop, Agrostis capillaris L.) in two P-deficient Andosols (a Pumice Soil and an Allophanic Soil). Pinus radiata rhizosphere had more soil organic matter, greater mycorrhizal hyphal length density, higher acid phosphatase activity, and more concentrated dissolved organic carbon than bulk soil or the rhizosphere of grass species in one or both soils. Concentrations of resin P and organic P in the P. radiata rhizosphere were higher than those in the grass rhizosphere and bulk soils, suggesting that P. radiata rhizosphere processes have a greater potential to accumulate organic P and mobilize soil P than understorey grass rhizosphere processes. This effect was less marked in the Allophanic Soil than in the Pumice Soil, probably because of the higher P-fixing capacity and lower plant-available P concentrations in the Allophanic Soil.
2
Chen, C. R., L. M. Condron, B. L. Turner, N. Mahieu, M. R. Davis, Z. H. Xu e R. R. Sherlock. "Mineralisation of soil orthophosphate monoesters under pine seedlings and ryegrass". Soil Research 42, n. 2 (2004): 189. http://dx.doi.org/10.1071/sr03018.
Testo completoAbstract (sommario):
The effects of radiata pine (Pinus radiata D. Don) seedlings and ryegrass (Lolium perenne L.) on the mineralisation of orthophosphate monoesters in 7 grassland soils were assessed in a 10-month pot trial using NaOH–EDTA extraction and solution 31P NMR spectroscopy. Extraction with NaOH–EDTA recovered 46–86% of the total soil P, and NaOH–EDTA-extractable organic P determined by molybdate colourimetry ranged between 194 and 715 mg/kg soil, representing 34–85% of the total soil organic P. Orthophosphate monoesters were the predominant species of the extracted organic P in all soils, with much smaller concentrations of orthophosphate diesters, and traces of phosphonates. Concentrations of orthophosphate monoesters were consistently lower in soils under pine (103–480 mg P/kg soil) compared with the initial soils (142–598 mg P/kg soil) and most soils under grass (122–679 mg/kg soil). Mineralisation of myo-inositol hexakisphosphate accounted for 18–100% of the total mineralisation of orthophosphate monoesters in most soils under radiata pine. This suggests that supposedly recalcitrant inositol phosphates are available for uptake by radiata pine, although the extent of this varies among soils.
3
Ryan, PJ. "Characteristics of soil and productivity of Pinus radiata (D Don) in New South Wales .II. Pedogenesis on a range of parent materials". Soil Research 24, n. 1 (1986): 103. http://dx.doi.org/10.1071/sr9860103.
Testo completoAbstract (sommario):
Soil profile descriptions were made at a series of 11-year-old unfertilized Pinus radiata stands in the Lithgow district of New South Wales. Catenas within three soil parent materials were selected to compare variation in soil physical and morphological properties with growth of P. radiata. These parent materials were a Silurian siltstone, a Permian conglomerate and a Silurian-Devonian rhyolite. Basal area growth of the P. radiata stands increased down catenas on the Silurian siltstone as soil depth to a root impeding layer increased. Plateau soils on the Permian conglomerate had hardsetting surfaces and high gravel contents, and were associated with very poor pine growth. By way of contrast, lower slope, colluvial gradational earths were deep, fine-textured soils and supported more productive pine stands. The Silurian-Devonian rhyolite parent material produced highly leached soils, commonly with conspicuously bleached A2 horizons and poor sandy textures of surface soil. Both physical and chemical features of the rhyolite interacted with pedological processes to affect adversely soil physical conditions and trace element availability, in particular boron. The poorer P. radiata growth on lower or concave slope in comparison with upper slope position was a result of increased soil leaching and horizon differentiation. This pattern contrasted with improved pine growth on the deeper soils on lower slopes on the two sedimentary parent materials. These case studies emphasize the importance of geology and pedological processes when evaluating the applicability of specific soil physical factors to site classification for P. radiata plantations.
4
Pérez-Cruzado, César, Benjamín Sande, Beatriz Omil, Pere Rovira, Manuel Martin-Pastor, Nieves Barros, Josefa Salgado e Agustín Merino. "Organic matter properties in soils afforested with Pinus radiata". Plant and Soil 374, n. 1-2 (8 settembre 2013): 381–98. http://dx.doi.org/10.1007/s11104-013-1896-5.
Testo completo
5
Saggar, S., C. B. Hedley e G. J. Salt. "Soil microbial biomass, metabolic quotient, and carbon and nitrogen mineralisation in 25-year-old Pinus radiata agroforestry regimes". Soil Research 39, n. 3 (2001): 491. http://dx.doi.org/10.1071/sr00012.
Testo completoAbstract (sommario):
To understand the effects of agroforestry on soil biological processes we assessed the conditions in Pinus radiata plantations of 50, 100, 200, and 400 stems/ha after 25 years of growth, and in a grassland. Agroforestry resulted in a 15–25% decline in soil organic C and N compared with grassland, and had a significant negative influence on soil microbial biomass. There was less microbial C and N in soils under 50–400 stems/ha of P. radiata than in soils under grassland (0 stems/ha). Soil carbon decomposition and microbial activity were measured by trapping the carbon dioxide produced by incubating soils over a 60-week period. The results showed that soil C decomposition rates were ~1.5 times as much (c. 15 mg CO2-C/kg soil) in soil from grassland as in that from plots with 50 or100 stems/ha (c. 10 mg CO2-C/kg soil), and were further reduced to one half (c. 5.5 mg CO2-C/kg soil) in the plots with 200 or 400 stems/ha. The soils under P. radiata gave off less carbon dioxide per unit of biomass (the metabolic quotient) than soils under grassland. These shifts in microbial biomass and its metabolic quotients appear to be associated with differences in the quantity and ‘quality’ of inputs and soil organic matter decomposition rates, and to reflect the land use change from grassland to forest. Given the general ability of soil microbial biomass to recolonise depopulated areas after tree harvest, we see no problem in restoring populations of these soil organisms vital in controlling nutrient cycling after tree felling, provided adequate adjustments to soil pH are made.
6
Mitchell, A. D., P. Loganathan, T. W. Payn e R. W. Tillman. "Magnesium fertiliser dissolution rates in pumice soils under Pinus radiata". Soil Research 38, n. 3 (2000): 753. http://dx.doi.org/10.1071/sr99083.
Testo completoAbstract (sommario):
Application of Mg fertilisers has been suggested as a means of reducing the incidence of Mg deficiency of forest trees in New Zealand and Europe. The objective of this study was to determine the rates of dissolution of a range of Mg fertilisers applied to a pumice soil (Typic Udivitrand). The rate of fertiliser dissolution was little influenced by whether the fertiliser was applied directly on to the soil surface (litter removed) or on to the litter layer in a Pinus radiata plantation. Twenty-seven months since fertiliser application the mean (with and without litter) percentage of Mg dissolved was in the sequence: Epsom salts > calcined magnesite 1–2 mm > granmag (a partially acidulated and granulated calmag product) > calcined magnesite 2–4 mm > forestry grade dolomite. The specific dissolution rate constants (mg/cm2 .day of fertiliser) for the slowly soluble Mg fertilisers calculated using an elemental sulfur oxidation cubic model were 587 for calcined magnesite 1–2 mm, 426 for calcined magnesite 2–4 mm, 385 for granmag, and 18 for forestry grade dolomite. In a laboratory incubation study the elemental sulfur oxidation cubic model described the rate of dissolution of Mg fertilisers within narrow fertiliser particle size ranges. The specific fertiliser dissolution rate constants, however, increased with decreases in particle size, suggesting that the rate of dissolution depends on factors other than surface area when particle sizes varied widely. Slowly soluble, alkaline Mg fertilisers had a significant liming effect on the soil. They were more effective in increasing soil exchangeable Mg than soluble Mg salts over a long-period and therefore, they are better fertilisers for P. radiata.
7
Falkiner, RA, PK Khanna e RJ Raison. "Effect of superphosphate addition on N mineralization in some Australian forest soils". Soil Research 31, n. 3 (1993): 285. http://dx.doi.org/10.1071/sr9930285.
Testo completoAbstract (sommario):
Pinus radiata stands are reported to accumulate increased N on addition of phosphatic fertilizers. Field and laboratory studies were initiated to determine if addition of superphoshate increases soil N mineralization in forest soils. In a field experiment, application of 200 kg P ha-1 as superphosphate to trenched plots in a Pinus radiata stand increased accumulated soil mineral-N contents by 122% and 82% above the control on two occasions. Application of 500 kg P ha-1 as superphosphate either alone or in combination with lime (10 Mg ha-1) increased in situ soil net N mineralization in a dry sclerophyll eucalypt forest from 20.7 (control) to 28.3 (+P) and 30.2 (+P+lime) kg N ha-1 yr-1 20 cm-1. Uptake by the vegetation accounted for all of the mineralized nitrogen. In a 180 day laboratory incubation using undisturbed soil columns (0-20 cm) from nine forest sites, seven soils showed a positive response to superphosphate (100 kg P ha-1) addition, with increases in N mineralization ranging from 14% to 117%. The response of N mineralization to superphosphate addition was not related to initial soil organic C, total N or P content in the 0-20 cm layer. However, soil pH and organic C combined to account for 76% of the variation in N mineralization response (P < 0.01). In the 0-5 cm layer of untreated soils, soil organic P content could explain 71% of the variation in net N mineralization. Addition of superphosphate appears to increase N mineralization in several Australian forest soils and the improved availability of N will enhance tree growth rates. The mechanisms underlying the response are still poorly understood and thus also our ability to predict its significance for tree nutrition on specific forest sites.
8
Turner, J., CH Thompson, ND Turvey, P. Hopmans e PJ Ryan. "A soil technical classification system for Pinus radiata (D. Don) plantations. I. Development". Soil Research 28, n. 6 (1990): 797. http://dx.doi.org/10.1071/sr9900797.
Testo completoAbstract (sommario):
A technical classification system for soils of Pinus radiata plantations is presented. The soil attributes used were mainly from published data and classes were established on an a priori basis from information and experience of plantation forestry with this species. The system is designed for field use and does not require laboratory analyses; it uses factors that are not affected by the presence of the forest species; the classes are coded so as to produce data suitable for computerized information systems. The attributes used are parent rock, texture profile, depth to and nature of any impeding layer, texture and condition of the uppermost 10 cm of soil, character of surficial horizons according to paler subsurface or exposed subsoil, and the condition and colour of the subsoil. A parent rock classification has been devised according to soil-forming potential; this reduces rock identification to 12 main classes so as to facilitate field recognition. The classification is aimed at assisting soil-based silvicultural management of P. radiata forests, providing a basis for transferring technology between forests, and at accumulating specific resource information for inclusion in forest management information systems.
9
Bolan, N. S., e S. Thiagarajan. "Retention and plant availability of chromium in soils as affected by lime and organic matter amendments". Soil Research 39, n. 5 (2001): 1091. http://dx.doi.org/10.1071/sr00090.
Testo completoAbstract (sommario):
Chromium is used as Cr(III) in the tannery industry and as Cr(VI) in the timber treatment industry. In this experiment, the effect of 2 liming materials [fluidised bed boiler ash (FBA) and lime] and an organic amendment (Pinus radiata bark) on the retention of Cr by 2 soils (Egmont and Tokomaru) was examined using both ‘batch’ and ‘column’ experiments. The effect of these amendments on the uptake of Cr from the Egmont soil, treated with various levels of Cr (0–3200 mg Cr/kg soil), was examined using sunflower (Helianthus annuus) plants. The transformation of Cr was examined by fractionation of Cr in soils. Addition of FBA and lime increased the retention of Cr(III), but had the opposite effect on the retention of Cr(VI). Addition of bark did not affect the retention of Cr(III), but it increased the retention of Cr(VI). Increasing additions of Cr increased Cr concentration in plants, resulting in decreased plant growth. The liming materials were found to be effective in reducing the phytotoxicity of Cr(III) and the Pinus radiata bark was effective for Cr(VI). In both Cr(III)- and Cr(VI)-contaminated soils, the concentrations of Cr were higher in the organic-bound, oxide-bound, and residual fractions than in the soluble and the exchangeable fractions. The concentrations of Cr in the soluble and the exchangeable fractions were higher in the Cr(VI)-contaminated than the Cr(III)-contaminated soil. Addition of the liming materials decreased the concentration of the soluble Cr(III) and bark decreased soluble Cr(VI) in soil. There was evidence for the reduction of Cr(VI) to Cr(III) in the bark-treated soils.
10
Ryan, PJ. "Boron retention within a catena of rhyolitic soils and Its effect on radiata pine growth and nutrition". Soil Research 27, n. 1 (1989): 135. http://dx.doi.org/10.1071/sr9890135.
Testo completoAbstract (sommario):
Boron deficiency in Pinus radiata (D. Don) plantations in N.S.W. has been particularly evident on soils derived from acid igneous parent materials. A slope sequence (catena) of soils on a rhyolitic parent material was selected to study the amount of boron retention and its relationship to soil development. The soils at three positions, a hillcrest, mid-slope and lower slope, were described and various soil chemical and physical properties were determined for each horizon. Tree height, deformity, survival and foliar chemistry of 6 year old P. radiata were measured in plots adjacent to the three soil profiles studied. Boron adsorption isotherms varied within individual soil profiles by horizon and also between the different soil profiles in the catena. Boron adsorption was highest in the hillcrest soil B horizons and lowest in the bleached A2 horizons of the lower slope soil. The Freundlich isotherm constant k was found to be significantly correlated with clay content (r = 0.88), exchangeable aluminium (r = 0.79, exchangeable potassium (r = 0.68), and dithionite-citrate extractable iron (r = 0.66). Leaching and illuviation of iron oxides and clay has been accentuated in the two soil profiles on the hillslope sites of the catena. As clay, aluminium and iron oxides have been removed from the surface horizons of the lower slope soil, the ability of these horizons to adsorb and therefore retain boron has been greatly diminished. Position on the catena also affected P. radiata growth survival and foliar chemistry. Tree height decreased while the incidence of deformity increased down the slope. It is suggested that the progressive deterioration in tree growth down the slope is mainly caused by the trees being increasingly affected by boron stress as a result of decreasing capacity of the soils to retain boron by adsorption against leaching towards the lower slope.
11
Olmedo, Guillermo F., Mario Guevara, Horacio Gilabert, Cristián R. Montes, Eduardo C. Arellano, Beatriz Barría-Knopf, Francisco Gárate et al. "Baseline of Carbon Stocks in Pinus radiata and Eucalyptus spp. Plantations of Chile". Forests 11, n. 10 (30 settembre 2020): 1063. http://dx.doi.org/10.3390/f11101063.
Testo completoAbstract (sommario):
Forest plantations have a large potential for carbon sequestration, playing an important role in the global carbon cycle. However, despite the large amount of research carried out worldwide, the absolute contribution of forest plantations is still incomplete for some parts of the world. To help bridge this gap, we calculated the amount of C stock in three fast growing forest species in Chile. Carbon pools in above-ground and below-ground biomass, forest floor, and soil were considered for this analysis. Across the plantation forests of Chile, carbon accumulated in the above-ground biomass was 181–212 Mg · ha−1 for Pinus radiata, 147–180 Mg · ha−1 for Eucalyptus nitens, and 95–117 Mg · ha−1 for Eucalyptus globulus (age 20–24 years for P. radiata and 10–14 years for Eucalyptus). Total C stocks were for 343 Mg · ha−1 for P. radiata, 352 Mg · ha−1 for E. nitens, and 254 Mg · ha−1 for E. globulus, also at the end of a typical rotation. The carbon pool in the forest floor was found to be significantly lower (less than 4% of the total) when compared to the other pools and showed large spatial variability. Our results agree with other studies showing that 30–50% of the total C stock is stored in the soil. The baseline data will be valuable for modelling C storage changes under different management regimes (changes in species, rotation length and stocking) and for different future climates. Given the contribution of soils to total carbon stocks, special attention should be paid to forest management activities that affect the soil organic carbon pool.
12
Sechi, C., S. Seddaiu, B. T. Linaldeddu, A. Franceschini e B. Scanu. "Dieback and Mortality of Pinus radiata Trees in Italy Associated with Phytophthora cryptogea". Plant Disease 98, n. 1 (gennaio 2014): 159. http://dx.doi.org/10.1094/pdis-05-13-0572-pdn.
Testo completoAbstract (sommario):
Pinus radiata D. Don is a forest tree species native to the Monterey Baja in California. Due to its rapid growth and desirable lumber and pulp qualities, between 1960 and 1980, about 12,000 ha of P. radiata were planted in Sardinia, Italy. The only disease reported on this conifer species has been Diplodia pinea, which causes tip and branch dieback (3). In January 2012, dieback and mortality of 25-year-old radiata pine trees were observed in a reforestation area of about 20 ha located in northern Sardinia (40°43′N, 9°22′E, 600 m a.s.l.). Symptoms included chlorosis, reddish-brown discoloration of the whole crown or dieback starting in the upper crown and progressing downward through the crown, and necrotic bark tissues at root collar. Approximately 25% of the trees were affected. In a first attempt, a Phytophthora species was consistently isolated from the rhizosphere of 23 symptomatic trees, which included necrotic fine roots using oak leaves as bait (4). Afterwards, it was also isolated from phloem samples taken from the margins of fresh lesions at the stem base and upper roots of affected trees using synthetic mucor agar medium (1). Isolation from soil samples of six healthy pine trees randomly selected in the site did not yield any Phytophthora isolate. On carrot agar (CA), Phytophthora colonies were stellate to slightly radiate with limited aerial mycelium. Sporangia were obpiryform, non-papillate, and non-caducous, measuring 46.9 to 51.2 × 29.1 to 32.6 μm (l:b ratio 1.9). Hyphal swellings were formed in chains or clusters; chlamydospores were not observed. These isolates had cardinal temperatures of <5°C, 25°C, and 35°C, respectively. Their morphological and cultural features were typical of Phytophthora cryptogea Pethybridge & Lafferty. They were heterothallic and produced oogonia with amphyginous antheridia when paired with an A2 mating type tester strain of P. cryptogea. This identity was corroborated by sequence analysis of the internal transcribed spacer (ITS) region of the rDNA. BLAST searches showed 99% homology with sequences of P. cryptogea available in GenBank (DQ479410 and HQ697245). The ITS sequence of a representative isolate (PH101) was submitted to GenBank (Accession Nos. KC603895). The strain PH101 was stored in the culture collection of the Department of Agriculture at the University of Sassari. Pathogenicity of isolate PH101 was verified by inoculating five freshly cut logs of radiata pine (1 m long and 15 cm diam.) with a 5-mm agar plug taken from the margin of 4-day-old culture grown on CA (4). The plug was inserted in a 5-mm hole made through the bark with a cork borer. Five control logs were inoculated with sterile CA. All logs were incubated in a growth chamber at 20°C. Phloem lesion sizes were assessed after 1 month and measured 9.7 ± 5.5 cm2 (average ± standard deviation). Control logs had no lesions. The pathogen was re-isolated from the lesions, thus fulfilling Koch's postulates. P. cryptogea has been previously reported in Australia, causing decline of radiata pine trees in wet and flooded soils (2). To our knowledge, this is the first report of P. cryptogea on P. radiata trees in Europe. References: (1) C. M. Brasier and S. A. Kirk. Plant Pathol. 50:218, 2001. (2) M. Bumbieris. Aust. J. Bot. 24:703, 1976. (3) A. Franceschini et al. Informatore Fitopatologico 1:54, 2006. (4) B. Scanu et al. For. Pathol. 43:340, 2013.
13
Mitchell, A. D., P. Loganathan, T. W. Payn e R. W. Tillman. "Effect of calcined magnesite on soil and Pinus radiata foliage magnesium in pumice soils of New Zealand". Soil Research 37, n. 3 (1999): 545. http://dx.doi.org/10.1071/s98085.
Testo completoAbstract (sommario):
Magnesium (Mg) deficiency is common in a number of forest regions in the world. It has been linked to a condition in P. radiata called ‘upper mid crown yellowing’ (UMCY) in New Zealand and ‘new type forest decline’ in Europe. Mg concentrations are low in many of New Zealand"s forest soils. With increases in the number of rotations and increased growth rates through tree breeding, Mg deficiency is expected to increase. This study was conducted to determine the fate of calcined magnesite (calmag) fertiliser applied at 150 kg Mg/ha at 2 sites in the Kaingaroa Forest near Rotorua, New Zealand. It also investigated the effectiveness of calmag in increasing the soil solution and soil exchangeable Mg in pumice soils and Mg concentrations in the pine needles, and in reducing the likelihood of UMCY 2 and 3 years after fertiliser application. In both sites and for both years of sampling the application of calmag fertiliser resulted in a significant increase in soil exchangeable and soil solution Mg in the 0–5 cm soil layer. Soil and soil solution pH had also been increased in the top 5 cm soil layer. Two years after application about 90% of the fertiliser applied had dissolved and about 70–80% of the Mg remained in a plant-available form (ammonium acetate exchangeable Mg) in the top 10 cm of soil. Calculations suggest that 3–10% of applied fertiliser had been lost due to leaching. Magnesium fertiliser application also resulted in significant reduction in the exchangeable K: Mg ratio and reduced exchangeable Al in the 0–5 cm soil layer. After 3 years, foliar Mg concentrations increased at all sites in the fertilised trees compared with the control trees, although differences were not yet significant. UMCY severity in the trees was also not significantly affected by the application of Mg fertiliser.
14
Romanyà, J., J. Cortina, P. Falloon, K. Coleman e P. Smith. "Modelling changes in soil organic matter after planting fast-growing Pinus radiata on Mediterranean agricultural soils". European Journal of Soil Science 51, n. 4 (dicembre 2000): 627–41. http://dx.doi.org/10.1111/j.1365-2389.2000.00343.x.
Testo completo
15
Romanya, J., J. Cortina, P. Falloon, K. Coleman e P. Smith. "Modelling changes in soil organic matter after planting fast-growing Pinus radiata on Mediterranean agricultural soils". European Journal of Soil Science 51, n. 4 (dicembre 2000): 627–41. http://dx.doi.org/10.1046/j.1365-2389.2000.00343.x.
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Adams, M. L., M. R. Davis e K. J. Powell. "Effects of grassland afforestation on exchangeable soil and soil solution aluminium". Soil Research 39, n. 5 (2001): 1003. http://dx.doi.org/10.1071/sr00054.
Testo completoAbstract (sommario):
The impact of land use change from grassland to conifer forest on the aluminium (Al) concentrations in soils and soil solutions was examined. Soils from grassland were compared with those from adjoining 15–19-year old forest stands at 3 contrasting pairs of sites in South Island, New Zealand. The site pairs were on a terrace [Pinus nigra/P. ponderosa, and grassland (CP)], and a hill slope [Pseudotsuga menziesii and grassland (CF)] in the Craigieburn range, Canterbury, and a hill slope in the Lammerlaw Range, Otago [P. radiata and grassland (LP)]. The sites had never been cultivated or fertilised, and for each pair the forest and grassland were similar in terms of soil and topography. The 1 M KCl exchangeable and 0.02 M CaCl 2 extractable Al levels at 0–10 cm were higher in forest than in grassland topsoil at CP and LP (P < 0.01). In soil solutions there was a trend for both ‘reactive Al’ and Al bound in labile organic complexes to be higher in forest soil at all sites, but site-pair differences were only significant at LP, and only for ‘reactive Al’. The increase in ‘reactive Al’ at this site was linked to the low pH and low base saturation. The ratios of exchangeable and soil solution Ca 2+ and Mg 2+ to ‘reactive Al’ were substantially lower in forest than grassland soils at all sites. Aluminium complexation capacity (Al-CC) values at all sites were higher in forest soil solutions than in grassland soil solutions. For the grassland and forest sites at LP, the Al-CC correlated strongly with the amount of soluble fulvic and humic matter present, as estimated from soil solution UV absorbance at 250 nm. In soils with the lowest percentage base saturation and buffering capacity (LP), afforestation of pastoral grassland with Pinus radiata significantly reduced soil pH and base cation levels, while increasing both soil and soil solution Al concentrations. Under such conditions (base saturation <20%), the increase in ‘reactive Al’ concentrations in soil solutions under fast growing conifer tree species may be sufficient to affect Mg uptake.
17
Simcock, R. C., R. L. Parfitt, M. F. Skinner, J. Dando e J. D. Graham. "The effects of soil compaction and fertilizer application on the establishment and growth of Pinus radiata". Canadian Journal of Forest Research 36, n. 5 (1 maggio 2006): 1077–86. http://dx.doi.org/10.1139/x06-009.
Testo completoAbstract (sommario):
Ground-based harvest operations in planted forests can adversely affect the soil and subsequently the productivity of the plantation. This study examined the effects of compaction, site preparation, and fertilization on soil physical and chemical properties and tree growth in a trial established at a second-rotation harvest on an imperfectly drained clay loam located in the North Island, New Zealand. Treatments were installed following harvest of Pinus radiata D. Don. There were four physical treatments: no treatment, compaction in rows by skidder, site preparation (rip and disk), and compaction followed by site preparation; the three nutrient treatments included no fertilizer, nitrogen (N), and N plus phosphorus (P). Response of P. radiata was studied for the first 4 years of growth. Compaction reduced survival of P. radiata at planting and during the first year of growth as the result of an increased oxygen deficit, caused by a reduction in macropore volume, and a shallower depth to the perched water table. Site preparation improved both survival of the seedlings and growth over 4 years. There was an initial growth response to N, but fertilizer did not increase survival of the seedlings. After 4 years, both site preparation and N plus P treatments gave approximately 10% extra growth, suggesting that N plus P may have been as effective as site preparation for improved growth of the trees that survived the first 2 years. However, since survival of seedlings is important to the economics of plantations, especially where planting densities are low, site preparation of soils with low macropore volume should be considered as a management tool.
18
AMIOTTI, N. M., O. BRAVO, P. ZALBA e N. PEINEMANN. "Effect of landscape position on the acidification of loess-derived soils under Pinus radiata". Austral Ecology 32, n. 5 (agosto 2007): 534–40. http://dx.doi.org/10.1111/j.1442-9993.2007.01725.x.
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Rivaie, Achmad Arivin. "Growth response of broom (Cytisus scoparius) growing with and without radiata pine (Pinus radiata) seedlings to different P levels in soils". Journal of Forestry Research 22, n. 4 (13 maggio 2011): 597–602. http://dx.doi.org/10.1007/s11676-011-0173-9.
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20
Fernandez, Irene, Juan Gabriel Álvarez-González, Beatríz Carrasco, Ana Daría Ruíz-González e Ana Cabaneiro. "Post-thinning soil organic matter evolution and soil CO2 effluxes in temperate radiata pine plantations: impacts of moderate thinning regimes on the forest C cycle". Canadian Journal of Forest Research 42, n. 11 (novembre 2012): 1953–64. http://dx.doi.org/10.1139/x2012-137.
Testo completoAbstract (sommario):
Forest ecosystems can act as C sinks, thus absorbing a high percentage of atmospheric CO2. Appropriate silvicultural regimes can therefore be applied as useful tools in climate change mitigation strategies. The present study analyzed the temporal changes in the effects of thinning on soil organic matter (SOM) dynamics and on soil CO2 emissions in radiata pine ( Pinus radiata D. Don) forests. Soil C effluxes were monitored over a period of 2 years in thinned and unthinned plots. In addition, soil samples from the plots were analyzed by solid-state 13C-NMR to determine the post-thinning SOM composition and fresh soil samples were incubated under laboratory conditions to determine their biodegradability. The results indicate that the potential soil C mineralization largely depends on the proportion of alkyl-C and N-alkyl-C functional groups in the SOM and on the microbial accessibility of the recalcitrant organic pool. Soil CO2 effluxes varied widely between seasons and increased exponentially with soil heating. Thinning led to decreased soil respiration and attenuation of the seasonal fluctuations. These effects were observed for up to 20 months after thinning, although they disappeared thereafter. Thus, moderate thinning caused enduring changes to the SOM composition and appeared to have temporary effects on the C storage capacity of forest soils, which is a critical aspect under the current climatic change scenario.
21
Theodorou, C., e G. D. Bowen. "Root morphology, growth and uptake of phosphorus and nitrogen of Pinus radiata families in different soils". Forest Ecology and Management 56, n. 1-4 (gennaio 1993): 43–56. http://dx.doi.org/10.1016/0378-1127(93)90102-s.
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22
Carlyle, J. Clive, Mark W. Bligh e EK Sadanandan Nambiar. "Woody residue management to reduce nitrogen and phosphorus leaching from sandy soil after clear-felling Pinus radiata plantations". Canadian Journal of Forest Research 28, n. 8 (1 agosto 1998): 1222–32. http://dx.doi.org/10.1139/x98-111.
Testo completoAbstract (sommario):
We studied the potential of woody residue management to reduce N and P leaching from sandy soils after clear-felling Pinus radiata D. Don. stands in southeastern Australia. Treatment variables were (i)branch diameter, (ii)branch mass, (iii)branch placement (surface or buried), and (iv)branch comminution. Treatments were applied to zero-tension lysimeters containing homogenized soil, forest floor, and green needles. Leachates from these treatments were collected weekly for 2 years and analysed for mineral N (Nm), soluble organic N, and total soluble P. Addition of 60 Mg·ha-1 of branch residue to the soil surface reduced Nm leaching by 13%, but the same quantity of buried branch reduced Nm leaching by 27%. Comminuting branches before burying further reduced Nm leaching. Much of the effect of placement, mass, and comminution on Nm leaching was related to differences in the surface area of branch material in contact with soil. Comminuting and burying branches reduced P leaching by 31%. An increase in branch N content after 2 years was linearly related to the reduction in Nm leached but accounted for only 23-48% of this reduction. Irrespective of treatment, there were linear relationships between the N and P concentrations in remaining material and the relative mass loss of wood and bark.
23
Ruiz-González, Ana Daría, e Juan Gabriel Álvarez-González. "Canopy bulk density and canopy base height equations for assessing crown fire hazard in Pinus radiata plantations". Canadian Journal of Forest Research 41, n. 4 (aprile 2011): 839–50. http://dx.doi.org/10.1139/x10-237.
Testo completoAbstract (sommario):
Crown fires combine high rates of spread, flame lengths, and intensities, making it virtually impossible to control them by direct action and having significant impact on soils, vegetation, and wildlife habitat. For these reasons, fire managers have great interest in preventive silviculture of forested landscapes to avoid the initiation and propagation of crown fires. The minimum conditions necessary to initiate and propagate crown fires are assumed to be strongly influenced by the stand structural variables canopy bulk density (CBD) and canopy base height (CBH). However, there is a lack of quantitative information on these variables and how to estimate them. To characterize the aerial fuel layers of Pinus radiata D. Don, the vertical profiles of canopy fuel in 180 sample plots of pure and even-aged P. radiata plantations were analysed. Effective CBD and CBH were obtained from the vertical profiles, and equations relating these variables to common stand variables were fitted simultaneously. Inclusion of the fitted equations in existing dynamic growth models, together with the use of current fire behaviour and hazard prediction tools, will provide a decision support system for assessing the crown fire potential of different silvicultural alternatives for this species.
24
Cartes-Rodríguez, Eduardo, Rafael Rubilar-Pons, Eduardo Acuña-Carmona, Jorge Cancino-Cancino, Jorge Rodríguez-Toro e Yuri Burgos-Tornería. "Potential of Pinus radiata plantations for use of harvest residues in characteristic soils of south-central Chile". Revista Chapingo Serie Ciencias Forestales y del Ambiente XXII, n. 2 (2016): 221–33. http://dx.doi.org/10.5154/r.rchscfa.2015.07.032.
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25
McLaren, R. G., A. Black e L. M. Clucas. "Changes in Cu, Ni, and Zn availability following simulated conversion of biosolids-amended forest soils back to agricultural use". Soil Research 48, n. 3 (2010): 286. http://dx.doi.org/10.1071/sr09138.
Testo completoAbstract (sommario):
In this study we examined the bioavailability and chemistry of Cu, Ni, and Zn in metal-spiked, biosolids-amended forest (Pinus radiata) soils that had undergone a simulated conversion back to agricultural use. Mixing of the biosolids-treated forest litter into the underlying mineral soil resulted in high concentrations of each metal in easily extractable and soil solution forms. There was also very little change in these concentrations during a subsequent 2-year incubation period of the samples. Chemical speciation of the soil solutions using WHAM 6 showed that Cu was dominated by organic complexes, whereas most Ni and Zn was present as Ni2+ and Zn2+, with generally <5% of these elements present as organic complexes. Addition of lime to the soils substantially decreased both readily extractable and soil solution metal concentrations. However, even in their unlimed state, although plant metal concentrations were increased by the original biosolids treatments, there were no adverse effects due to the metals on plant growth as determined in a wheat germination and seedling growth test. In this study, the DGT technique showed considerable promise for assessing metal availability to plants. However, the study suggests that conversion of biosolids-treated forest soils back for agricultural use is unlikely to result in any substantial problems related to the metal loadings built up in the forest litter layer.
26
Carlyle, J. Clive, e EK Sadanandan Nambiar. "Relationships between net nitrogen mineralization, properties of the forest floor and mineral soil, and wood production in Pinus radiata plantations". Canadian Journal of Forest Research 31, n. 5 (1 maggio 2001): 889–98. http://dx.doi.org/10.1139/x01-008.
Testo completoAbstract (sommario):
We examined the relationship between net nitrogen (N) mineralization (subsequently termed N mineralization) in the forest floor and mineral soil (00.15 m) of 20 Pinus radiata D. Don plantations ranging in age from 23 to 59 years, how mineralization was influenced by soil properties, and its relationship to wood production. Forest floor properties had a narrower relative range than the same set of mineral soil properties. Total N in the litter layer was 5.09.5 g·kg1 compared with 0.232.53 g·kg1 in mineral soil. Laboratory rates of net N mineralization ranged between 1.1 and 9.7 mg·kg1·day1 in forest floor and between 0.02 and 0.53 mg·kg1·day1 in mineral soil. The range in litter lignin (35.348.0%) was especially narrow, despite the large range in stand productivity. Nitrogen mineralized in the forest floor was not correlated with any of the measured forest floor or mineral soil properties. Nitrogen mineralized per unit mineral soil N (ksn) was negatively correlated with the mineral soil N to organic phosphorus ratio (N/Po) (r2 = 0.82). In mineral soil a relationship combining N/Po and total N concentration explained 90% of the variation in N mineralized. Nitrogen mineralized in the forest floor was correlated with that mineralized in the mineral soil when expressed per unit C or N (r2 = 0.54 or 0.57, respectively). Thus, the quality of organic matter in the forest floor partly reflected the quality of organic matter in the mineral soil with respect to N mineralization. Mineralization in mineral soil dominated the net N available to the stand. For sandy soils, wood production (m3·ha1·year1) was correlated with N mineralized in the forest floor + mineral soil (r2 = 0.71). In P. radiata stands growing in southern Australia, rates of wood production per unit N mineralized and per unit rainfall appear to be substantially higher than those of a wide range of natural and planted stands in North America.
27
M.P., Herve, Balocchi O.A. e Penaloza R. "Silvopastoral sheep and pine systems for small farmers in southern chile". Proceedings of the British Society of Animal Production (1972) 1990 (marzo 1990): 159. http://dx.doi.org/10.1017/s0308229600019395.
Testo completoAbstract (sommario):
Chile's X region (40-43 degrees south), has around 1 million has. of marginal soils with forest-livestock potential use, red clay slopes being dominant, located in the coastal ranges. Subsistance agriculture with increasing erosion damage is carried out on small properties which also practice extensive livestock production with sheep and cattle.In order to study alternative land use which could benefit small peasant farmers agroforestry with sheep and pines was attempted.Two agroforestry systems using Pinus radiata D.Don and sheep were developed. System I started in 1977 planting 8 ha at 2,5 x 7m spacing. Romney ewes were introduced in 1979 initially at a stocking rate of 5/ha. Prunnings were carried out in 1980, 1984 and 1986; thinnings were done in 1982,1984 and 1986, to 7m and 200 st/ha respectively.System 2 used 20ha of conventional 2 x 2m forest planted in 1974. It was prunned and thinned in 1982,1984 and 1986 to Bm and 200 st /ha respectively and stocked initially with 4.7 Romney ewes/ha in 1983.
28
Liu, Q., P. Loganathan e M. Hedley. "Influence of Ectomycorrhizal Hyphae on Phosphate Fractions and Dissolution of Phosphate Rock in Rhizosphere Soils of Pinus radiata". Journal of Plant Nutrition 28, n. 9 (1 settembre 2005): 1525–40. http://dx.doi.org/10.1080/01926230500203056.
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29
Scott, Neal A., Roger L. Parfitt, Des J. Ross e Gareth J. Salt. "Carbon and nitrogen transformations in New Zealand plantation forest soils from sites with different N status". Canadian Journal of Forest Research 28, n. 7 (1 luglio 1998): 967–76. http://dx.doi.org/10.1139/x98-067.
Testo completoAbstract (sommario):
Interactions between soil nutrient cycling processes are likely to influence N losses following disturbance in forest ecosystems. During a 340-day laboratory incubation, we examined C and N transformations in three sandy soils of different N status from Pinus radiata D. Don plantations before clear-cutting. The soils were a high N status Andisol (losing -N in streamwater) and a fertilized and unfertilized Entisol. In contrast to other forest ecosystems, -N accumulated readily in all mineral soils and in the Andisol forest floor but did not accumulate until day 63 and 210 in the fertilized and unfertilized Entisol forest floor, respectively. However, gross nitrification occurred from day 42 in both Entisol treatments. Net nitrification in the Entisol forest floor began when substrate C/N ratio declined to about 40, possibly because of decreased C availability and decreased competition for both -N and -N in conjunction with a lower microbial C/N ratio. Carbon and gross N mineralization rates (per unit of C or N, respectively) correlated positively (r2 = 0.93) in mineral soil but correlated negatively in the forest floor, probably because of major differences in C and N quality and potential differences in microbial community structure. The mean residence time of N in mineral-N pools was higher for soils from the N-rich site, in part because of lower microbial N demand. These results suggest that sudden removal of C inputs (such as at harvest) may cause greater disruption of internal soil N cycles on nutrient poor sites, increasing the proportional losses of N as compared to nutrient-rich sites.
30
Halliday, M. M., e R. L. Knowles. "Farm forestry for economic and environmental sustainability - A new decision support system for farm foresters". NZGA: Research and Practice Series 10 (1 gennaio 2003): 85–90. http://dx.doi.org/10.33584/rps.10.2003.2981.
Testo completoAbstract (sommario):
The objective of this programme is to provide farm foresters and others with knowledge about sustainable and profitable land use with commercial tree crops. Initially the study examined the role of trees in stabilising soils when planted on eroding hill country pasture. Three species - radiata pine, Douglas-fir, and poplar - were compared for effects in reducing erosion. Tree size, tree stocking per hectare, root tensile strength, and rate of decay of roots after harvest were found to be important. Erosion control becomes effective once a stand of trees reached the equivalent of 30 tonnes/ha of radiata pine root biomass. Silviculture, and choice of species, determines to what extent this critical threshold is achieved. Decision support software, developed in this programme as "calculators', estimate the 'Equivalent Farming Gross Margin' of crops of radiata pine, and Douglas-fir, compared to the livestock previously grazing the land. The calculators, which run under Microsoft EXCELTM, also allow the identification of the most profitable silviculture for the tree crop, and generate yield tables. The calculators are being applied in two case studies; the first involves calibrating the radiata pine calculator for Hawkes Bay and the Wairarapa against actual tree data. Calibration of the calculator for bare land is also being studied. The second study will investigate how well tree crops can compete financially with pastoral farming systems in the Lake Taupo catchment, where there are increasing concerns about nutrient in-flows from pastoral farming. Further enhancements of the calculators are planned which will permit calibration against younger stands, and evaluation of a much wider range of silviculture. Keywords: farm forestry, erosion, root biomass, root strength, financial return, IRR, PNW, farming gross margin, Pinus radiata, Douglas-fir, poplar
31
Singh, Brajesh K., Kevin R. Tate, Gokul Kolipaka, Carolyn B. Hedley, Catriona A. Macdonald, Peter Millard e J. Colin Murrell. "Effect of Afforestation and Reforestation of Pastures on the Activity and Population Dynamics of Methanotrophic Bacteria". Applied and Environmental Microbiology 73, n. 16 (15 giugno 2007): 5153–61. http://dx.doi.org/10.1128/aem.00620-07.
Testo completoAbstract (sommario):
ABSTRACT We investigated the effect of afforestation and reforestation of pastures on methane oxidation and the methanotrophic communities in soils from three different New Zealand sites. Methane oxidation was measured in soils from two pine (Pinus radiata) forests and one shrubland (mainly Kunzea ericoides var. ericoides) and three adjacent permanent pastures. The methane oxidation rate was consistently higher in the pine forest or shrubland soils than in the adjacent pasture soils. A combination of phospholipid fatty acid (PLFA) and stable isotope probing (SIP) analyses of these soils revealed that different methanotrophic communities were active in soils under the different vegetations. The C18 PLFAs (signature of type II methanotrophs) predominated under pine and shrublands, and C16 PLFAs (type I methanotrophs) predominated under pastures. Analysis of the methanotrophs by molecular methods revealed further differences in methanotrophic community structure under the different vegetation types. Cloning and sequencing and terminal-restriction fragment length polymorphism analysis of the particulate methane oxygenase gene (pmoA) from different samples confirmed the PLFA-SIP results that methanotrophic bacteria related to type II methanotrophs were dominant in pine forest and shrubland, and type I methanotrophs (related to Methylococcus capsulatus) were dominant in all pasture soils. We report that afforestation and reforestation of pastures caused changes in methane oxidation by altering the community structure of methanotrophic bacteria in these soils.
32
Mosquera-Losada, M. Rosa, Nuria Ferreiro-Domínguez e Antonio Rigueiro-Rodríguez. "Fertilization in pastoral and Pinus radiata D. Don silvopastoral systems developed in forest and agronomic soils of Northwest Spain". Agriculture, Ecosystems & Environment 139, n. 4 (dicembre 2010): 618–28. http://dx.doi.org/10.1016/j.agee.2010.10.007.
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33
Greven, M., S. Green, B. Robinson, B. Clothier, I. Vogeler, R. Agnew, S. Neal e S. Sivakumaran. "The impact of CCA-treated posts in vineyards on soil and ground water". Water Science and Technology 56, n. 2 (1 luglio 2007): 161–68. http://dx.doi.org/10.2166/wst.2007.485.
Testo completoAbstract (sommario):
Grapes in Marlborough are typically grown on a vertical shoot positioned trellis system (VSP). For this purpose Pinus radiata posts are treated with CCA, a mixture of copper (Cu), chromium (Cr) and arsenic (As), giving a wood concentration of 1,730, 3,020 and 2,410 mg/kg, respectively on a dry matter basis. The CCA levels around the posts in different soils were investigated and assessed for the potential leaching of CCA into ground water. An initial survey showed leaching of all three heavy metals from the treated posts into the soil surrounding the posts (0.2% of the total vineyard area) compared with the control, depending on vineyard age and soil type. The rate of movement out of the posts was calculated from posts placed in lysimeters. HortResearch's Soil Plant Atmosphere Model (SPASMO) was used to predict the leaching rate of CCA. For As, leaching was found to be 5 mg/post/month, with the Cr rate being about twice that. Further modelling revealed a steady plume of As moving downwards after about 200–300 years. However, long-term hydrogeological modelling showed that sufficient aquifer water flow prevented the accumulation of CCA in the ground water. The modelling approaches are discussed.
34
Bian, L., W. J. Gapare, M. Ivković, P. Jefferson e H. X. Wu. "Genetic variation between and within ex-situ native-provenance collections of Pinus radiata D. Don planted in Australia and New Zealand". Silvae Genetica 60, n. 1-6 (1 dicembre 2011): 276–85. http://dx.doi.org/10.1515/sg-2011-0036.
Testo completoAbstract (sommario):
AbstractA total of 1226 increment cores were sampled from two provenance trials of Pinus radiata D. Don planted in New Zealand (Kaingaroa) and Australia (Kangaroovale), to study variation and inheritance of wood density in selections from three mainland California natural populations: Año Nuevo, Monterey and Cambria. The study represents a back-to-back comparison of the same provenance and family material on contrasting sites between New Zealand and Australia. Monterey was significantly different to Año Nuevo and Cambria at Kaingaroa (p<0.05), and had slightly higher density, whereas all provenances were almost identical and not significantly different at Kangaroovale. However, there were significant differences for wood density at family level for Año Nuevo and Cambria at Kangaroovale. No significant provenance or family differences were detected for core length at either site. The estimates of heritability for wood density were all above 0.50 and generally higher at Kaingaroa than at Kangaroovale. Estimates of additive genetic correlations between wood density and core length were imprecise. Genotype × site interactions for density appeared minor (estimated type-B genetic correlation= 0.70) despite substantial differences in rainfall and soils. The similarity of Cambria to Año Nuevo for density is an interesting result because the genetic base of the present Australian and New Zealand plantations has been shown to be from Año Nuevo and Monterey. Infusion of Cambria material would increase the overall genetic base of the radiata pine breeding programs, with potential long-term benefits, despite the often disappointing growth performance of material collected from Cambria.
35
Tate, K. R., D. J. Ross, S. Saggar, C. B. Hedley, J. Dando, B. K. Singh e S. M. Lambie. "Methane uptake in soils from Pinus radiata plantations, a reverting shrubland and adjacent pastures: Effects of land-use change, and soil texture, water and mineral nitrogen". Soil Biology and Biochemistry 39, n. 7 (luglio 2007): 1437–49. http://dx.doi.org/10.1016/j.soilbio.2007.01.005.
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36
Wang, XJ, PJ Smethurst e GK Holz. "Nitrogen mineralisation indices in ferrosols under eucalypt plantations of North-Western Tasmania: association with previous land use". Soil Research 34, n. 6 (1996): 925. http://dx.doi.org/10.1071/sr9960925.
Testo completoAbstract (sommario):
Potentially mineralisable N was studied in the laboratory and in the held in ferrosols from eucalypt plantations and pastures in north-western Tasmania. The plantation sites previously supported either Pinus radiata plantations (ex-pine), mixed eucalypt-myrtle forest (ex-mixed), or open Eucalyptus delegatensis forest with a grass understory (ex-dele). Ranges of concentrations of organic C and total N, and C to N ratio, were 6.9-13.6%, 0.297-0.978%, and 10.3-30.4, respectively. The concentration of organic C was independent of previous land use, but rankings for total N, anaerobically mineralisable N, and extractable N in hot KCl were pasture > to ex-dele = ex-mixed > ex-pine. The ratio C:N in theex-pine group (23.6) was higher than ratios in other groups (13.1-15.6). Anaerobically mineralisable N ranged from 49 to 214 �g/g, and was highly correlated with total N and extractable N in hot KCl at 95�C for 16 h (r = 0.83 for both cases, P < 0.001). The C:N ratio was negatively correlated with total N and anaerobically mineralisable N (r = 0.56 and 0.70, P < 0.01). The results indicated that the pasture soils had greater availability of mineral N, and that total N, C:N ratio, and anaerobically mineralisable N may provide useful information for assessing N mineralisation in these soils.
37
Snowdon, P., J. S. Holtsapffel e Julie A. Davis. "Boron extracted with mannitol from ignited soils and its relationship with the development of boron deficiency of Pinus radiata grown in pots and in the field". Communications in Soil Science and Plant Analysis 24, n. 17-18 (novembre 1993): 2153–64. http://dx.doi.org/10.1080/00103629309368944.
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38
Rivaie, A. A., P. Loganathan, J. D. Graham, R. W. Tillman e T. W. Payn. "Effect of phosphate rock and triple superphosphate on soil phosphorus fractions and their plant-availability and downward movement in two volcanic ash soils under Pinus radiata plantations in New Zealand". Nutrient Cycling in Agroecosystems 82, n. 1 (23 febbraio 2008): 75–88. http://dx.doi.org/10.1007/s10705-008-9170-6.
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Su, Jingjun, Hailong Wang, Mark O. Kimberley, Katie Beecroft, G. N. Magesan e Chengxiao Hu. "Distribution of heavy metals in a sandy forest soil repeatedly amended with biosolids". Soil Research 46, n. 7 (2008): 502. http://dx.doi.org/10.1071/sr07203.
Testo completoAbstract (sommario):
The suitability for land application of biosolids can be limited by the presence of heavy metals. We investigated the distribution of heavy metals in the soil of a research trial within a Pinus radiata (D. Don) plantation following repeated applications of aerobically digested liquid biosolids. The trial is located on a sandy soil at Rabbit Island near Nelson, New Zealand. Biosolids were applied in 1997, 2000, and 2003, at 3 application rates: 0 (control), 300 (standard), and 600 kg N/ha (high). Litter layer and soil samples (down to 1 m) were taken from the trial site and analysed to assess the accumulation of heavy metals (Cu, Zn, Cd, Cr, Pb, and Ni) within the soil profile and the effect of repeated biosolids application on metal availability and mobility. Sequential fractionation methods were used to evaluate the distribution of exchangeable, specifically sorbed, oxide bound, organic bound, and residual fractions of the metals. Concentrations of Cr, Cu, Pb, and Zn in the litter layer were significantly (P < 0.05) higher in the high biosolids-treated plots than the control, indicating that the litter layer had retained considerable amounts of biosolids-derived metals. Significantly elevated concentrations of environmentally available Cu in the topsoil (0–0.1 m) were observed in plots receiving the high biosolids treatment and residual Cu concentration was significantly higher in the biosolids treatments, but apart from an accumulation of oxide-bound Zn in the 0.1–0.25 m layer, no accumulation of other metals in the soil was observed. The residual fraction was the most abundant pool for all metals examined, indicating low bioavailability. Total concentrations of the metals in both biosolids-treated and untreated control soils were very low (e.g. <7 mg Cu/kg, <30 mg Zn/kg). Although there were no significant changes in concentrations below the topsoil, mass balance calculation implied that a proportion of biosolids-derived Zn in the high biosolids treatment may have been leached through the soil profile.
40
Sudmeyer, R., e F. Flugge. "The economics of managing tree - crop competition in windbreak and alley systems". Australian Journal of Experimental Agriculture 45, n. 11 (2005): 1403. http://dx.doi.org/10.1071/ea04155.
Testo completoAbstract (sommario):
Re-introducing trees and shrubs into agricultural landscapes as agroforestry systems establishes a tension between long-term objectives, such as increasing shelter, water use, nature conservation and harvesting tree products, and the short-term objective of maximising crop and pasture profitability. This paper describes the growth of crops, pastures and trees at the tree–crop interface in agroforestry systems and the economic returns from alley farming and windbreak systems using various tree–crop competition management strategies in the Esperance region of Western Australia. Severing lateral tree roots (root-pruning), harvesting mallees and allowing them to coppice, or thinning trees for sawlog regimes increased the yield of crops and pastures in the competition zone. In some instances, these increases were significant: root-pruning increased the annual return from crops grown in the competition zone of Pinus radiata by up to $548/km of the tree line at 1 site. Conversely, root-pruning reduced tree growth by 14–43% across all sites. Therefore, where trees provide benefits, such as shelter from damaging winds, the benefits of reduced tree–crop competition may not offset the consequent reduction in rate of tree growth. For mallee–crop alley systems on agriculturally productive soils, mallee growth rates must be high enough to compensate for crop losses in the competition zone. On less agriculturally productive soils, block-planting mallees may be more profitable than alley systems or crops without competition (sole-crops). This research has shown that competition management strategies can be used to manipulate the relative productivity of trees, crops and pasture at the tree–agriculture interface. The use of these strategies will depend on the relative economic value of tree and crop products and the value placed on other tree benefits, such as shelter and reduced groundwater recharge.
41
Dick, M. A., e K. Dobbie. "Species of Fusarium on Pinus radiata in New Zealand". New Zealand Plant Protection 55 (1 agosto 2002): 58–62. http://dx.doi.org/10.30843/nzpp.2002.55.3919.
Testo completoAbstract (sommario):
The common diseases of pines caused by Fusarium species in New Zealand are dampingoff and root rot disorders of seedlings in forest nurseries The emergence of pine pitch canker disease caused by Fusarium subglutinans f sp pini as a serious threat to Pinus radiata plantations has increased the need for an awareness of the species associated with pines in New Zealand Standard morphological procedures were used to identify Fusarium cultures isolated from diseased pines and from soil in forest nurseries Fusarium oxysporum and F solani were the most commonly found species in bareroot P radiata nurseries and were obtained from both seedlings and from soil The species most frequently obtained from branches and needles of older trees in plantations were F avenaceum and F sambucinum but these were not associated with serious disease
42
Smethurst, Philip, Andrew Knowles, Keith Churchill, Ann Wilkinson e Arthur Lyons. "Soil and foliar chemistry associated with potassium deficiency in Pinus radiata". Canadian Journal of Forest Research 37, n. 6 (giugno 2007): 1093–105. http://dx.doi.org/10.1139/x06-307.
Testo completoAbstract (sommario):
We required an improved understanding of K deficiency and diagnosis in Pinus radiata D. Don (radiata pine). A rapid growth response to K fertilization (100 kg·ha–1) in the presence of weed control confirmed K deficiency in a 2-year-old stand. Tree growth did not respond to N fertilization, and weed control alone appeared insufficient to maximize tree growth. Temporal patterns in visual symptoms of K deficiency suggested they were worst at the end of a drought, and improved after several months of above-average rainfall that coincided with an increase in soil temperature. Soil chemistry generally responded predictably to fertilization, but K fertilization increased soil solution Ca and Mg concentrations without changing exchangeable concentrations. With weed control, a doubling of stem growth response to K fertilizer was associated with a 270% increase in soil solution K (natural variation amongst control plots), 51% increase in exchangeable K, and 39% increase in foliar K. Relationships between seedling growth and hydroponic concentrations of K were consistent with the incidence of K deficiency in the field; predicting these deficiencies using soil exchangeable concentrations was less clear. This study advances the interpretation of soil and foliar chemistry in relation to K and Mg deficiency in P. radiata.
43
Ross, D. J., K. R. Tate, N. A. Scott, R. H. Wilde, N. J. Rodda e J. A. Townsend. "Afforestation of pastures with Pinus radiata influences soil carbon and nitrogen pools and mineralisation and microbial properties". Soil Research 40, n. 8 (2002): 1303. http://dx.doi.org/10.1071/sr02020.
Testo completoAbstract (sommario):
In New Zealand, Pinus radiata D. Don is frequently planted on land under pasture primarily for production forestry, but with the added advantage of potentially offsetting carbon dioxide (CO2) emissions from energy and industrial sources. Conversion of pasture to P. radiata plantations can, however, result in lowered contents of soil carbon (C) at some sites. We here examine the effects of this land-use change on soil C and nitrogen (N) pools, and on microbial properties involved in the cycling of these nutrients, at 5 paired sites, each with an established pasture and P. radiata plantation. Four sites had first-rotation trees aged 12–30 years and the other site second-rotation trees aged 20 years. In mineral soil at 0–10 cm depth, total and microbial C and N, extractable C, CO2-C production, and, generally, net mineral-N production were lower under P. radiata than under pasture; differences were significant (P < 0.05), except for total and extractable C at 2 sites. Differences between these land uses were less distinct in soil at 10–30 cm depth. On an area basis, total C in 0–30 cm depth soil was lower under P. radiata than under pasture at most sites, but significantly lower at only one site. Total N, microbial C and N, and CO2-C and net mineral-N production were, however, again generally significantly lower under P. radiata. These ecosystem differences were less marked, although still present, except for CO2-C production, when forest litter (LFH material) was included in the area calculations. Overall, our study suggests that afforestation with P. radiata leads to a reduction in total N, microbial biomass, and microbial activity, but a less consistent effect on soil C storage after one rotation.
44
COMERFORD, N. B., e M. F. SKINNER. "RESIDUAL PHOSPHORUS SOLUBILITY FOR AN ACID, CLAYEY, FORESTED SOIL IN THE PRESENCE OF OXALATE AND CITRATE". Canadian Journal of Soil Science 69, n. 1 (1 febbraio 1989): 111–17. http://dx.doi.org/10.4141/cjss89-010.
Testo completoAbstract (sommario):
A highly weathered, clayey soil was sampled 14 yr after a Pinus radiata stand was broadcast fertilized with 0, 50 and 200 kg P ha−1 as ordinary superphosphate. Incremental loadings of oxalate and citrate anions from 10 to 100 μmol of anion g−1 soil were evaluated for increased soluble, reactive P (SRP) and soluble, nonreactive (SNP) P. Sorption isotherms were compared to evaluate the effect of the previous fertilization on P sorption by the soil material sampled, and also to measure SNP displacement by orthophosphate-P. A portion of the SNP pool was more readily released than SRP and orthophosphate displaced a significant amount of SNP. After 14 yr the effect of fertilization was still obvious in the sampled soil material. Much of the organic anion-soluble P was in the SRP form. Key words: Citrate, organic P, orthophosphate, oxalate, Pinus radiata, residual P
45
Parfitt, R. L., e D. J. Ross. "Long-term effects of afforestation with Pinus radiata on soil carbon, nitrogen, and pH: a case study". Soil Research 49, n. 6 (2011): 494. http://dx.doi.org/10.1071/sr11106.
Testo completoAbstract (sommario):
Planting of Pinus radiata D. Don in previously grazed pastures is a common land-use change in New Zealand. Although carbon (C) accumulates relatively rapidly in the trees, there have been no studies of the annual effect on soil C content during the early years of establishment. Here, we study soil properties under P. radiata and pasture each year over 11 years after P. radiata was planted into pasture that had been grazed by sheep. Under the growing trees, grass was gradually shaded out by the unpruned trees, and completely disappeared after 6 years; needle litterfall had then increased appreciably. By year 9, soil microbial C and nitrogen (N), and net N mineralisation, were significantly lower under pine than under pasture. Soil pH, sampled at 0–100 mm in early spring each year, decreased by ~0.3 units under pine and increased by ~0.3 units under pasture. Close to the pine stems, total C and N decreased significantly for 3 years, while ~100 kg N/ha accumulated in the trees. Soil C and N increased in subsequent years, when litterfall increased. Overall, the mineral soil under pine lost ~500 kg N/ha over 11 years, consistent with uptake by the trees. Leaching losses (estimated using lysimeters) in year 9 were 4.5 kg N/ha.year. These data indicate that ~6 Mg C/ha may have been lost from the mineral soil at this site. The difficulties associated with measuring losses of C are discussed.
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Falkiner, R. A., e P. J. Polglase. "Fate of applied phosphorus in an effluent-irrigated Pinus radiata plantation". Soil Research 37, n. 6 (1999): 1095. http://dx.doi.org/10.1071/sr99014.
Testo completoAbstract (sommario):
We examined the fate of applied phosphorus (P) in a young Pinus radiata plantation in south-eastern Australia, spray-irrigated with secondary-treated municipal effluent. Measurements included changes (before irrigation, and after 5 years) in total P, total organic P, total inorganic P, labile P, and sorption and desorption characteristics. During the first 5 years a total of 363 kg/ha of P was applied at an average concentration of 5.4 mg/L. Irrigation changed the forms and distribution of P throughout the profile (0–1 m). Increases in labile inorganic P (membrane-exchangeable, bicarbonate-extractable, and in soil solution) were confined mostly to the 0–0.5 m horizon, and wholly within the 0–0.7 m horizon. In addition, large amounts of organic P (204 kg/ha) were mineralised within the surface 0.7 m, due to stimulation of decomposer activity by increased soil water. Mineralisation, therefore, provided a significant and additional input of inorganic P to soil. Irrigation and P additions changed both the placement and curvature of soil sorption isotherms. Retention capacity (0–0.5 m), calculated from P sorption isotherms, decreased by 180 kg/ha. Desorbable P, determined by sequential extraction with dilute acid, increased by 184 kg/ha. Thus, these 2 independent methods of measuring the changes in exchangeable P gave the same result. Of the total inorganic P added to the soil (in effluent and mineralised), 25% remained in the exchangeable form; the rest was retained unavailable for short-term exchange and migration through soil. After 5 years, fluxes (kg/ha) of P in the 0–0.7 m horizon were: input in effluent less storage in vegetation (323), change in total organic P (–204), change in total inorganic P (517), net change in total P (313). Thus, 97% of the net amount of P added in effluent was recovered in the surface 0.7 m. Results have implications for the way in which P retention capacity is calculated under effluent irrigation.
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Watt, Michael S., Murray R. Davis e Roger L. Parfitt. "Improved nutritional status of Cupressus lusitanica when grown adjacent to Pinus radiata". Canadian Journal of Forest Research 39, n. 4 (aprile 2009): 882–87. http://dx.doi.org/10.1139/x09-005.
Testo completoAbstract (sommario):
We examined how a mixture of Pinus radiata D. Don and Cupressus lusitanica Mill. influences foliage element concentrations at 20 sites, covering a fertility gradient. Foliage element concentrations of plants at plot boundaries, where the two species grew adjacent to each other, were compared with those of plants at plot centres, where they were surrounded by plants of the same species. For C. lusitanica, plot position significantly affected nitrogen (N), phosphorus (P), and sulphur (S) with concentrations of these elements at the plot boundary exceeding concentrations at the plot centre by 10%–14%. For P. radiata, plants at the plot boundary had a significantly greater P concentration and lower N/P ratio than plants at the centre, but differences between positions were less than that for C. lusitanica (<7%). For C. lusitanica, the difference between foliage concentrations of N and P at the plot boundary and centre significantly declined as the mean plot concentrations of these elements increased. It is likely that C. lusitanica at the boundary benefited from the greater availability of N, P, and S in the root rhizosphere, where they were mobilized from soil organic matter by the ectomycorrhizae of P. radiata. We also suggest that P. radiata at the plot boundary may have benefited from mobilization of P by the endomycorrhizae of C. lusitanica.
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Jeong, J., N. S. Bolan e C. Kim. "Allocation of photoassimilated carbon of radiata pine (Pinus radiata) seedlings as affected by soil water stress". Australian Forestry 84, n. 1 (2 gennaio 2021): 4–12. http://dx.doi.org/10.1080/00049158.2020.1864944.
Testo completo
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Watt, Michael S., David J. Palmer, Mark O. Kimberley, Barbara K. Höck, Tim W. Payn e David J. Lowe. "Development of models to predict Pinus radiata productivity throughout New Zealand". Canadian Journal of Forest Research 40, n. 3 (marzo 2010): 488–99. http://dx.doi.org/10.1139/x09-207.
Testo completoAbstract (sommario):
Development of spatial surfaces describing variation in productivity across broad landscapes at a fine resolution would be of considerable use to forest managers as decision support tools to optimize productivity. In New Zealand, the two most widely used indices to quantify productivity of Pinus radiata D. Don are Site Index and 300 Index. Using an extensive national data set comprising a comprehensive set of national extent maps, multiple regression models and spatial surfaces of these indices for P. radiata were constructed. The final models accounted for 64% and 53%, respectively, of the variance in Site Index and 300 Index. For Site Index, variables included in the final model in order of importance were mean annual air temperature, fractional mean annual available root-zone water storage, mean annual windspeed, length and slope factor, categories describing Land Environments of New Zealand (LENZ), and major soil parent material. The variables included in the final model of 300 Index in order of importance included the degree of ground frost during autumn, fractional mean annual available root-zone water storage, categories describing LENZ, vegetation classification, foliar nitrogen, taxonomic soil order, and major soil parent material. These results highlight the utility of thematic spatial layers as driving variables in the development of productivity models.
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Hom, Sanjeet Kumar, Sauradipta Ganguly, Yasir Ullah Bhoru e Ajmal Samani. "Effect of chemical modification on dimensional stability of Pinus radiata D. Don using acetic anhydride". Journal of Forest Science 66, No. 5 (31 maggio 2020): 208–17. http://dx.doi.org/10.17221/13/2020-jfs.
Testo completoAbstract (sommario):
Chemical modification is used to efficiently improve some properties of wood to make it suitable for specific end uses. Modification using acetic anhydride (AA) is found suitable to make the wood more stable dimensionally. Pinus radiata wood samples treated with pyridine catalyzed AA were exposed to four different treatment methods comprising vacuum dipping and full cell method (cured with and without chemical). Physical properties like weight percentage gain (WPG), bulking coefficient, swelling coefficient (S) due to the chemical, water absorption and anti-swelling efficiency (ASE) were assessed for a comparative analysis. Results indicated a significant reduction in water absorption of acetylated wood. The swelling coefficients of all the treatments were found in the range of 3.86–4.96, which was twice to three times less than in the control (11.72) attributing 55–64% improvement in dimensional stability. Samples treated with full cell method and cured in the chemical mixture showed minimum swelling coefficient and best anti-swelling efficiency. All the four treatment methods chosen for the study returned significantly better dimensional stability as compared to untreated wood.