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971.
Kevin Lombard Mick O’Neill Robert Heyduck Blake Onken April Ulery John Mexal Adrian Unc 《Agroforestry Systems》2011,81(1):45-56
Composted sewage sludge (biosolids) supply plant available Fe and may represent a sustainable alternative to more costly chelated
Fe fertilizers currently used to supplement nutrition in hybrid poplar test plots of elevated soil pH. To test the response
of poplars, field plots were amended with composted biosolids at two agricultural rates: 22.75 and 44.5 Mg ha−1. Iron EDDHA served as a fertilizer check and control plots received no amendment. The hybrid poplar OP-367 (Populus deltoides × P. nigra) was planted on a 3.6 m grid spacing. Significant amounts of P and Fe originating from the sewage treatment process were
detected in soils 13 months after amending. Chlorosis evaluated with a SPAD-502 meter, showed that poplars amended with biosolids
remained the least chlorotic and had greater tree growth when compared to Fe EDDHA and control plots during two growing seasons.
Biosolids show promise as a cost effective alternative for the remediation of Fe chlorosis in hybrid poplar agroforestry plantations
and present new opportunities in northwestern New Mexico for municipalities seeking solid waste land disposal options. 相似文献
972.
María Eugenia Salgado Salomón Carolina Barroetaveña Mario Rajchenberg 《New Forests》2011,41(2):191-205
We investigated if Pinus ponderosa plantations in Patagonia are able to produce viable mycorrhizal inocula towards adjacent grasslands, which only harbor endomycorrhizal
vegetation. We hypothesized that these inocula have the potential to contribute to the establishment of naturally disseminated
seedlings. Also, we determined the main fungal taxa involved in this process. Seven plantations in the onset of their reproductive
phase and located in the Patagonian native forest/steppe ecotone (Argentina) were selected. Soil samplings were obtained at
nine points along a 450 m long, W-E transect established in each plantation. Soil bioassays were performed in a greenhouse,
with P. ponderosa seedlings acting as hosts for mycorrhizal inocula present in soil samples, during 12 months. Mycorrhization percentage, morphotype
richness and morphotype composition was determined through morphological evaluation. Viable ecto- and ectendomycorrhizal inocula
were found disseminated outside plantations. The amount of mycorrhizal inoculum followed a decreasing function with distance
to plantation edges. Mycorrhizal fungal genus Rhizopogon and “E-strain” mycorrhizal types appeared as pioneering taxa regarding seedlings colonization, being the most persistent
and frequent symbionts found. Plantations, thus, facilitate the surrounding terrain for newcoming seedlings through the dispersion
of mycorrhizal fungal inocula. 相似文献
973.
Commercial Tectona grandis plantations using clones have attracted considerable interest for lumber production in tropical regions where small areas
are frequent. However, studies on wood properties are limited. Therefore, the purpose of this study is to group clones with
similar wood color characteristics using the CIELab system, and mechanical resistance by dynamic stiffness (Ed) in order to obtain different types of clones for different climate and edaphic conditions. It was found that lightness (L*), yellowness (b*), redness (a*), and Ed are similar to those found for other plantation trees. These wood characteristics are significantly influenced by clone and
site. Variance due to clone and site went from 31 to 53% and from 2.95 to 24.22%, respectively. Another source of variance
was distance from pith, with the exception of parameter b*, which was not affected. Finally, clones were grouped (using multivariate analysis) according to color and mechanical resistance.
This analysis established 4 groups by color and 5 groups by Ed. Clone clustering will allow us to choose or use clones with similar wood properties according to site and environmental
conditions increasing area production and wood quality uniformity. 相似文献
974.
Katja Kehlenbeck Roeland Kindt Fergus L. Sinclair Anthony J. Simons Ramni Jamnadass 《Agroforestry Systems》2011,83(2):133-147
Agroforestry systems are potentially suitable for conservation of tree genetic resources. Farmers around Mt. Kenya usually
integrate trees into their farm. Large parts of these trees seem to be of exotic origin, whereas indigenous species have priority
for conservation. This study aimed at determining on-farm richness, composition and frequency of indigenous and exotic woody
species around Mount Kenya to assess the suitability of farms for the conservation of indigenous tree species. 265 on-farm
plots of 0.5 ha size each were selected in 18 different agro-ecological zones by using a stratified sampling scheme. All woody
species within the plot were recorded with their local and scientific names. Total species richness was 424 (including 306
indigenous ones), mean richness per plot 16.5 species (including 8.8 indigenous ones). Eight out of the 10 most frequent species
were exotic ones with Grevillea robusta from Australia ranking first (found on almost 76% of the surveyed farms). The proportion of indigenous species increased
with increasing aridity and temperature. Dominance of exotic species was found at farms of humid mid- and highlands. Ordination
analysis revealed that mostly exotic species contributed to separation of farms in the highlands and upper midlands, whereas
indigenous species in the lower midlands and lowlands. As the frequencies of most indigenous trees were low, only parts of
the surveyed farms can contribute to conservation of tree genetic resources, particularly the less intensively managed farms
of the more arid lands. Farmers’ access to knowledge on valuable indigenous tree species and to quality seedlings of these
trees need to be improved to increase indigenous species’ frequencies on farms and possibly to replace some of the exotic
species in the future. 相似文献
975.
In the present study, we are reporting permeability and pharmacokinetics of nobiletin in rat plasma and brain, using a validated reverse phase high performance liquid chromatographic method. Protein precipitation method was used for the extraction of nobiletin and coumarin (IS) from rat plasma and brain tissue. The system was run in isocratic mode with mobile phase consisting of potassium dihydrogen ortho-phosphate (pH 4.5; 0.04 mM) and acetonitrile in ratio of 50:50, v/v. The total chromatographic run time was 9.0 min. The method was proved to be accurate and precise at linearity range of 0.05–10 μg/mL with a correlation coefficient (r) of ≥ 0.994 in rat plasma and ≥ 0.995 in rat brain. The intra- and inter-day precision and accuracy values are found to be within the assay variability limits as per the FDA guidelines. Nobiletin was found stable in the battery of stability studies viz., bench-top, auto-sampler, freeze/thaw cycles and long term storage in a freezer at − 70 ± 10 °C. Maximum concentrations of nobiletin in both plasma and brain were observed at 1 h after single oral dosing (50 mg/kg). The maximum concentration in plasma and brain were 1.78 and 4.20 μg/mL, respectively. The AUC0–t in plasma and brain were 7.49 and 20.66 μg·h/mL, respectively. The mean elimination half life (t1/2) in plasma and brain were 1.80 and 11.42 h, respectively. The Parallel Artificial Membrane Permeability Assay (PAMPA) permeability of nobiletin was found to be high at both pH 4.0 and 7.0. 相似文献
976.
977.
Vishal Singh Ashish TewariSatya P.S. Kushwaha Vinay K. Dadhwal 《Forest Ecology and Management》2011,261(11):1945-1949
Biomass and carbon sequestration rate of a young (four year old) mixed plantation of Dalbergia sissoo Roxb., Acacia catechu Willd., and Albizia lebbeck Benth. growing in Terai region (a level area of superabundant water) of central Himalaya was estimated. The plantation is seed sown in the rainy season of year 2004 and spread over an area of 44 ha. Allometric equations for both above and below ground components were developed for three tree species. The density of trees in the plantation was 1322 trees ha−1 The diameters of trees were below 10 cm. Five diameter classes were defined for D. sissoo and A. catechu and 3 for A. lebbeck. 5 trees were harvested in each diameter class. Individual tree allometry was exercised for developing the allometric equations relating tree component (low and above ground) biomass to d.b.h. Post analysis equations were highly significant (P > 0.001) for each component of all species. In the plantation Holoptelia integrifolia Roxb. (Family Ulmaceae) has been reduced to shrub form because of frost. Only the aboveground biomass of H. integrifolia and other shrubs were estimated by destructive harvesting method. Herbaceous forest floor biomass and leaf litter fall were also estimated. The total forest vegetation biomass was 10.86 Mg ha−1 in 2008 which increased to 19.49 Mg ha−1 in 2009. The forest is sequestering carbon at the rate of 4.32 Mg ha−1 yr−1. 相似文献
978.
Keith E. Woeste 《林业研究》2011,22(3):353-359
Three kinds of plant growth regulators, gibberellinA 4/7 (GA 4/7 ), 6-benzylaminopurine (BA), and chlormequat chloride (CCC), were evaluated for their ability to promote strobilus and cone production in a Chinese pine (Pinus tabuliformis Carr.) clonal seed orchard. Treatments (0, 250, 500, or 1000 mg L -1 ) were applied during three periods (June- July, July-August and August-September) in 2005. Of the three plant growth regulators, GA 4/7 was the best for promoting flower and cone production. Trees sprayed... 相似文献
979.
Five different isoforms (IrlVHA-c1-c5) of V-ATPase subunit c (VHA-c) were cloned from a Japanese iris (Iris lactea Pall. var. chinensis Fisch. Koidz) cDNA library using degenerate primers PCR and the 5'-RACE technique. The sequence analysis showed the open reading frame (ORF) of the IrlVHA-c1 c5 to be 495 bp, corresponding to a protein of 164 amino acids. Among the five isoforms, IrlVHA-c1 and IrlVHA-c2 are completely homologous. The IrlVHA-c protein is localized at the vacuolar membrane as indicated by a g... 相似文献
980.
Effects of silviculture treatments in a hurricane-damaged forest on carbon storage and emissions in central Hokkaido,Japan 总被引:1,自引:0,他引:1
Hurricanes cause abrupt carbon reduction in forests, but silviculture treatment can be an effective means of quickly regenerating and restoring hurricane-damaged sites. This study assessed how silviculture treatments affect carbon balance after hurricane damage in central Hokkaido, Japan. We examined carbon storage in trees and underground vegetation as well as carbon emissions from silviculture operations in 25-year-old stands, where scarification and plantation occurred just after hurricane damage. The amount of carbon stored varied according to silviculture treatment. Among three scarification treatments, a scarified depth of 0 cm (understory vegetation removal) led to the largest amount of carbon stored (64.7 t·ha-1 C). Among four plantation treatments, the largest amount of carbon was stored in a Larix hybrid (L. gmelinii var. japonica × L. kaempferi) plantation (80.3 t·ha-1 C). The plantation of Abies sachalinensis was not successful at accumulating carbon (40.5·ha-1 C). The amount of carbon emitted from silviculture operations was 0.05-0.14 t·ha-1 C, and it marginally affected the net carbon balance of the silviculture project. Results indicate that silviculture treatments should beperformed in an appropriate way to effectively recover the ability of carbon sequestration in hurricane-damaged forests. 相似文献