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Carbon sequestration and soil fertility of tropical tree plantations and secondary forest established on degraded land 总被引:1,自引:0,他引:1
Purpose
Much tropical land requires rehabilitation but the capacity of reforestation with plantations or naturally regenerating secondary forests for overcoming soil degradation remains unclear. We hypothesised that desirable effects, including improved soil fertility and carbon sequestration, are achieved to a greater extent in Acacia mangium plantations and secondary forests than in Eucalyptus urophylla plantations.Methods
We tested our hypothesis across soil and climate gradients in Vietnam with linear mixed-effect models and other, comparing A. mangium and E. urophylla plantations, secondary forests and pasture.Results
A. mangium plantations and secondary forests showed a positive correlation between biomass production and desirable soils properties including increased soil carbon, nitrogen and phosphorus, and reduced bulk density. All plantations, but not secondary forests, caused increases in soil acidity. Eight-year old A. mangium plantations contained most carbon in biomass+soil, and secondary forests and pastures had similar or higher soil carbon. E. urophylla plantations had the lowest soil carbon status, raising doubt about their sequestration capacity in current 6–8 year rotations.Conclusions
The study demonstrates that appropriate reforestation enhances soil fertility and promotes carbon sequestration on degraded tropical lands and that unmanaged secondary forests are effective at improving soil fertility and sequestering carbon at low cost. 相似文献3.
Background and aims
Interacting effects of atmospheric N deposition on the degree to which tree demand for other nutrients is met by soil supply has seldom been explored in Mediterranean-type ecosystems. We hypothesized that patterns for the relative availability of N and P in soils will be matched by variations in process rates related to soil organic P cycling and by shifts from N to P limitation of tree growth.Methods
We examined N/P relationships in Mediterranean-fir (Abies pinsapo) forests from two nearby regions differing in N deposition levels.Results
N pools and transformation rates and the contribution of organic fractions to the labile P pool in soils showed increasing trends toward the pollution source. Phosphomonoesterase activity (PME) in bulk soils, root PME per unit biomass (but not per unit soil volume) and biomass accumulation in P-fertilized root-in-growth cores incubated in situ were also the highest at the sites receiving elevated N deposition, indicating P limitation. In contrast, forest stands in the region farther from the pollutant source were N-limited (preferential root growth in N-rich soil microsites) and showed lower PME activities and higher total fine root biomass.Conclusions
In the forests under elevated N deposition, higher values for an overall indicator of soil N status matched with indications of an accelerated soil organic P subcycle and P-limitation of tree growth. 相似文献4.
Francis Q. Brearley 《Plant and Soil》2013,367(1-2):465-476
Background and aims
The aim of this study is to enhance our knowledge of nitrogen (N) cycling and N acquisition in tropical montane forests through analysis of stable N isotopes (δ15N).Methods
Leaves from eight common tree species, leaf litter, soils from three depths and roots were sampled from two contrasting montane forest types in Jamaica (mull ridge and mor ridge) and were analysed for δ15N.Results
All foliar δ15N values were negative and varied among the tree species but were significantly more negative in the mor ridge forest (by about 2 ‰). δ15N of soils and roots were also more negative in mor ridge forests by about 3 ‰. Foliar δ15N values were closer to that of soil ammonium than soil nitrate suggesting that trees in these forests may have a preference for ammonium; this may explain the high losses of nitrate from similar tropical montane forests. There was no correlation between the rankings of foliar δ15N in the two forest types suggesting a changing uptake ratio of different N forms between forest types.Conclusions
These results indicate that N is found at low concentrations in this ecosystem and that there is a tighter N cycle in the mor ridge forest, confirmed by reduced nitrogen availability and lower rates of nitrification. Overall, soil or root δ15N values are more useful in assessing ecosystem N cycling patterns as different tree species showed differences in foliar δ15N between the two forest types. 相似文献5.
Background and aims
Climate change alters regional plant species distributions, creating new combinations of litter species and soil communities. Biogeographic patterns in microbial communities relate to dissimilarity in microbial community function, meaning novel litters to communities may decompose differently than predicted from their chemical composition. Therefore, the effect of a litter species in the biogeochemical cycle of its current environment may not predict patterns after migration. Under a tree migration sequence we test whether litter quality alone drives litter decomposition, or whether soil communities modify quality effects.Methods
Litter and soils were sampled across an elevation gradient of different overstory species where lower elevation species are predicted to migrate upslope. We use a common garden, laboratory microcosm design (soil community x litter environment) with single and mixed-species litters.Results
We find significant litter quality and microbial community effects (P?<?0.001), explaining 47 % of the variation in decomposition for mixed-litters.Conclusion
Soil community effects are driven by the functional breadth, or historical exposure, of the microbial communities, resulting in lower decomposition of litters inoculated with upslope communities. The litter x soil community interaction suggests that litter decomposition rates in forests of changing tree species composition will be a product of both litter quality and the recipient soil community. 相似文献6.
Alicja A. Babst-Kostecka Christian Parisod Cécile Godé Pierre Vollenweider Maxime Pauwels 《Plant and Soil》2014,383(1-2):245-256
Background and aims
Pseudometallophytes are model organisms for adaptation and population differentiation because they persist in contrasting edaphic conditions of metalliferous and non-metalliferous habitats. We examine patterns of genetic divergence and local adaptation of Biscutella laevigata to assess historical and evolutionary processes shaping its genetic structure.Methods
We sampled all known populations of B. laevigata in Poland and analyzed respective soil metal concentrations. For genotyping we used nine nuclear microsatellite loci. Population genetic pools were identified (Bayesian clustering) and we estimated genetic parameters and demographic divergence between metallicolous and non-metallicolous populations (ABC-approach).Results
Populations clustered into two groups which corresponded to their edaphic origin and diverged 1,200 generations ago. We detected a significant decrease in genetic diversity and evidence for a recent bottleneck in metallicolous populations. Genetic structure was unrelated to site distribution but is rather influenced by environmental conditions (i.e. soil metal concentration).Conclusions
The intriguing disjunctive distribution of B. laevigata in Poland results from a fragmentation of the species range during the Holocene, rather than recent long-distance-dispersal events. The genetic structure of populations, however, continues to be modified by microevolutionary processes at anthropogenic sites. These clear divergence patterns promote B. laevigata as a model species for plant adaptation to polluted environments. 相似文献7.
Root foraging capacity depends on root system architecture and ontogeny in seedlings of three Andean Chenopodium species 总被引:1,自引:0,他引:1
Ricardo Alvarez-Flores Thierry Winkel Anh Nguyen-Thi-Truc Richard Joffre 《Plant and Soil》2014,380(1-2):415-428
Aims
Morphological and ontogenetic variation in root system architecture holds ecological significance, particularly in low-resource habitats where soil rooting is critical for both seedling establishment and water and nutrient uptake. To assess this variation under contrasted agroecological backgrounds, root architecture and rooting patterns were compared in Andean populations of Chenopodium hircinum, Chenopodium pallidicaule and two ecotypes (wet- and dry-habitat) of Chenopodium quinoa.Methods
Seedlings were grown in rhizotrons under controlled water and nutrient availability. Root branching and elongation dynamics were characterized during 6 weeks after germination, while leaf area, above and below-ground biomass, and specific root length were determined at the end of the experiment.Results
Despite large differences in aboveground biomass, all populations showed similar herringbone root systems. The dry-habitat C. quinoa had generally the highest root trait values, with fast taproot elongation, thick roots and long root segments resulting in high total root length and deep root proliferation.Conclusion
Irrespective of their contrasting agroecological background, the studied chenopods displayed a similar root system topology. However, from very early development stages, they showed differential root foraging patterns with two extremes: fast and vigourous rooting at depth in the dry-habitat C. quinoa, and shallow and thin root system in C. pallidicaule adapted to shallow-soil and high-altitude habitats. 相似文献8.
C:N:P stoichiometry in Australian soils with respect to vegetation and environmental factors 总被引:7,自引:0,他引:7
Aims
We estimate organic carbon (C): total nitrogen (N): total phosphorus (P) ratios in soils under Australia’s major native vegetation groups.Methods
We use digital datasets for climate, soils, and vegetation created for the National Land and Water Resources Audit in 2001. Analysis-of-variance is used to investigate differences in nutrient ratios between ecosystems. Linear discriminant analysis and logistic regression are used to investigate the relative importance of climatic variables and soil nutrients in vegetation patterns.Results
We find that the N:P and C:P ratios have a greater range of values than the C:N ratio, although major vegetation groups tend to show similar trends across all three ratios. Some apparently homeostatic groupings emerge: those with very low, low, medium, or high N:P and C:P. Tussock grasslands have very low soil N, N:P, and C:P, probably due to frequent burning. Eucalypt woodlands have low soil N:P and C:P ratios, although their total P level varies. Rainforests and Melaleuca forests have medium soil N:P and C:P ratios, although their total P level is different. Heathlands, tall open eucalypt forests, and shrublands occur on soils with low levels of total P, and high N:P and C:P ratios that reflect foliar nutrient ratios and recalcitrant litter.Conclusions
Certain plant communities have typical soil nutrient stoichiometries but there is no single Redfield-like ratio. Vegetation patterns largely reflect soil moisture but for several plant communities, eucalypt communities in particular, soil N and P (or N:P) also play a significant role. Soil N:P and the presence of Proteaceae appear indicative of nutrient constraints in ecosystems. 相似文献9.
J. A. Ramírez J. D. León-Peláez D. Craven D. A. Herrera C. M. Zapata M. I. González-Hernández J. Gallardo-Lancho W. Osorio 《Plant and Soil》2014,378(1-2):215-226
Background and aims
Exotic coniferous species have been used widely in restoration efforts in tropical montane forests due to their tolerance to adverse conditions and rapid growth, with little consideration given to the potential ecological benefits provided by native tree species. The aim of this study was to elucidate differences in litterfall and nutrient flow between a montane oak forest (Quercus humboldtii Bonpl.) and exotic coniferous plantations of pine (Pinus patula Schltdl. & Cham.) and cypress (Cupressus lusitanica Mill.) in the Colombian Andes.Methods
Litter production, litter decomposition rate, and element composition of leaf litter were monitored during 3 years.Results
Litter production in the oak forest and pine plantation was similar, but considerably lower in the cypress plantation . Similar patterns were observed for nutrient concentrations in litterfall, with the exception of Ca which was three times higher in the cypress plantation. The annual decay rate of litter was faster in the montane oak forest than in either of the exotic coniferous plantations. The potential and net return of nutrients to the forest floor were significantly higher in oak forest than in the exotic coniferous plantations.Conclusions
Future restoration programs should consider new species that can emulate the nutrient flow of native broadleaf species instead of exotic species that tend to impoverish soil nutrient stocks in tropical montane forests. 相似文献10.
Ricardo A. G. Viani Ricardo R. Rodrigues Todd E. Dawson Rafael S. Oliveira 《Plant and Soil》2011,349(1-2):341-353
Background and Aims
Cerradão (Brazilian woodland savannas) and seasonally dry forests (SDF) from southeastern Brazil occur under the same climate but are remarkably distinct in species composition. The objective of this study was to evaluate the role of soil origin in the initial growth and distribution of SDF and Cerradão species.Methods
We conducted a greenhouse experiment growing Cerradão and SDF tree seedlings over their soil and the soil of the contrasting vegetation type. We evaluated soil nutrient availability and seedling survivorship, growth and leaf functional traits.Results
Despite the higher nutrient availability in SDF soils, soil origin did not affect seedling survivorship. The three SDF species demonstrated home-soil advantage, enhanced growth with increasing soil nutrient availability and had higher growth rates than Cerradão species, even on Cerradão soils. Growth of Cerradão seedlings was not higher on Cerradão soil and, overall, was not positively correlated with soil nutrient availability.Conclusions
SDF species are fast-growing species while Cerradão trees tend to be slow-growing species. Although savanna soil reduces growth of forest species, our findings suggest that soil chemical attributes, alone, does not exclude the occurrence of SDF seedlings in Cerradão and vice-versa. 相似文献11.
Background and aims
Roots have morphological plasticity to adapt to heterogeneous nutrient distribution in soil, but little is known about crop differences in root plasticity. The objective of this study was to evaluate root morphological strategies of four crop species in response to soil zones enriched with different nutrients.Methods
Four crop species that are common in intercropping systems [maize (Zea mays L.), wheat (Triticum aestivum L.), faba bean (Vicia faba L.), and chickpea (Cicer arietinum L.)] and have contrasting root morphological traits were grown for 45 days under uniform or localized nitrogen and phosphorus supply.Results
For each species tested, the nutrient supply patterns had no effect on shoot biomass and specific root length. However, localized supply of ammonium plus phosphorus induced maize and wheat root proliferation in the nutrient-rich zone. Localized supply of ammonium alone suppressed the whole root growth of chickpea and maize, whereas localized phosphorus plus ammonium reversed (maize and chickpea ) the negative effect of ammonium. The localized root proliferation of chickpea in a nutrient-rich zone did not increase the whole root length and root surface area. Faba bean had no significant response to localized nutrient supply.Conclusions
The root morphological plasticity is influenced by nutrient-specific and species-specific responses, with the greater plasticity in graminaceous (eg. maize) than leguminous species (eg. faba bean and chickpea). 相似文献12.
M. I. Cabello-Conejo C. Becerra-Castro A. Prieto-Fernández C. Monterroso A. Saavedra-Ferro M. Mench P. S. Kidd 《Plant and Soil》2014,379(1-2):35-50
Aim
Rhizobacteria can influence plant growth and metal accumulation. The aim of this study was to evaluate the effect of rhizobacterial inoculants on the Ni phytoextraction efficiency of the Ni-hyperaccumulator Alyssum pintodasilvae.Method
In a preliminary screening 15 metal-tolerant bacterial strains were tested for their plant growth promoting (PGP) capacity or effect on Ni bioaccumulation. Strains were selected for their Ni tolerance, plant growth promoting traits and Ni solubilizing capacity. In a re-inoculation experiment five of the previously screened bacterial isolates were used to inoculate A. pintodasilvae in two contrasting Ni-rich soils (a serpentine (SP) soil and a sewage sludge-affected agricultural (LF) soil).Results
Plant growth was greater in serpentine soil (where it grows naturally) than in the LF soil, probably due to Cd phytotoxicity. Rhizobacterial inoculants influenced plant growth and Ni uptake and accumulation, but the effect of the strains was dependent upon soil type. The increase in plant biomass and/or Ni accumulation significantly promoted shoot Ni removal.Conclusion
One strain (Arthrobacter nicotinovorans SA40) was able to promote plant growth and phytoextraction of Ni in both soil types and could be a useful candidate for future field-based trials. 相似文献13.
Sukristijono Sukardjo Daniel M. Alongi Yaya I. Ulumuddin 《Trees - Structure and Function》2014,28(4):1105-1113
Key message
Mangroves in rapidly expanding Southeast Asian river deltas form floristically simple zones dominated by a few highly regenerative species adaptable or tolerant to rapid sedimentation and extensive river flooding.Abstract
The size class distribution, community composition and spatial structure of five representative mangrove forests in the rapidly expanding Cimanuk river delta on Java were determined. These deltaic forests are species-poor (eight true mangrove species) and spatially segregated into three distinct floristic zones: (1) a fringing, low intertidal zone co-dominated by Avicennia marina and A. officinalis, with less abundant Bruguiera parviflora, Rhizophora apiculata, and R. mucronata; (2) a zone transitional between the low and mid intertidal in which Avicennia and Rhizophora spp. co-dominate; and (3) a mid intertidal zone dominated by R. mucronata and R. apiculata. Numerically dominated by seedlings (52,500–73,500 seedlings ha?1) and saplings (5,268–5,660 saplings ha?1), all five forests are relatively young and actively regenerating. Positive correlations of tree stem diameter and tree height with soil organic matter and P concentrations, salinity, the soil C/N ratio, pH, and silt/clay composition highlight the importance of soil factors in sustaining forest growth. The low diversity and relative structural simplicity of these rapidly growing and regenerating forests may be attributed to adaptation or tolerance to flooding and the rapid sedimentation and seaward expansion of the delta. 相似文献14.
Florencia Soteras Daniel Renison Alejandra G. Becerra 《Trees - Structure and Function》2014,28(1):173-182
Key message
Outplanted Polylepis australis seedling growth, survival and mycorrhizal response were not influenced by inoculation with soil from different vegetation types. Seedling inoculation would not be essential for reforestation practices.Abstract
Polylepis forests are one of the most endangered high mountain ecosystems of South America and reforestation with native Polylepis species has been recommended. To determine whether native soil inoculation could help in reforestation success, a field trial was set up to evaluate the response of outplanted P. australis seedlings to the inoculation with soils from three vegetation types (a grassland, a mature forest and a degraded forest) and a sterile soil, used as control. We evaluated seedlings performance: growth and survival for 18 months, root/shoot ratio, phosphorous content and arbuscular mycorrhizal fungal (AMF) colonization. To interpret performance patterns we evaluated the colonization potential of the three inoculum soils and the changes of the AMF community composition of the seedlings rhizosphere in relation to inoculation treatment and season. Our main results showed no significant differences in seedlings survival and growth between treatments. The colonization potential of grassland and degraded forest soils was ~25 times greater than mature forest soil and specific spore density of some morphospecies varied with season. However, AMF spore community of seedlings rhizosphere became homogenized after outplanting and was similar between treatments after 12 months. Therefore, we conclude that soil inoculation is not essential for outplanted P. australis survival and increase in height, and thus all the tested soils could be used as inocula, including grassland soils which in practice are the easiest to collect. 相似文献15.
Chunzhang Zhao Liying Zhu Jin Liang Huajun Yin Chunying Yin Dandan Li Nannan Zhang Qing Liu 《Plant and Soil》2014,382(1-2):189-201
Aim
This study aimed at predicting how sub-alpine coniferous ecosystems respond to global changes in the Eastern Tibetan Plateau by understanding soil microbial communities and activities, as well as variation in the quality and quantity of soil organic matter.Methods
An experiment was conducted to examine soil microbial communities and their related soil processes in rhizospheric soil of two coniferous species that were exposed to two levels of temperature (unwarmed and infrared heater warming) and two levels of nitrogen (unfertilized and 25 g N m?2 a?1) from April 2007.Results
Four-year night warming alone slightly affected the phospholipid fatty acid contents of the microbial community. However, the combination of nitrogen addition and soil warming significantly affected soil microbial composition while reducing the biomass of major microbial groups and the activities of most enzymes, especially in Abies faxoniana plots. The combination of warming and nitrogen addition increased soil labile C and N pools in Picea asperata plots and was beneficial for soil recalcitrant C, as well as for labile and total C and N pools in A. faxoniana plots.Conclusion
Results indicated that future warming will slightly affect soil microbial communities and their related soil processes. However, warming combined with high nitrogen deposition will significantly constrain soil microbial biomass and enzyme activities, consequently increasing soil C and N pools in sub-alpine coniferous forests of this region. 相似文献16.
Cleise Cordeiro Da Cruz Ursula Neira Mendoza Joaquim Barbosa Queiroz José Francisco Berrêdo Salustiano Vilar Da Costa Neto Rubén Jose Lara 《Plant and Soil》2013,368(1-2):393-406
Background and aims
The Bragança Peninsula, in northern Brazil is characterized by macrotides (4 m) and specific edaphic conditions, which determine the local mangrove forest’s development. This study, conducted during the dry season evaluated the spatial patterns of Rhizophora mangle and Avicennia germinans species across an inundation gradient.Methods
Along a transect of 700 m, measurements of structure forest, soil moisture, porewater salinity, extractable phosphorus (extr.-P) in sediments, and phosphorus in the leaves (leaf-P) were conducted.Result
The A. germinans (100 %) occurred in high intertidal (HI) zone. A. germinans (59 %) and R. mangle (41 %) co-occurred in mid intertidal (MI) zone, while R. mangle (58 %) predominated in low intertidal (LI) zone, followed by A. germinans (37 %) and Laguncularia racemosa (5 %). Covariance analysis (ANCOVA) indicated that salinity and soil moisture means are significantly different between the mangrove forests, but do not correlate with inundation frequency (IF). The means of extr.-P were significantly different in mangrove forests and correlated with IF and leaf-P.Conclusion
The inundation frequency, the availability of P in the sediments, phosphorus in the leaves and interstitial salinity are all important factors contributing to the distribution of the mangrove tree species A. germinans and R. mangle on the Bragança Peninsula. 相似文献17.
Background and Aims
Mangrove forests are globally important sites of carbon burial that are increasingly exposed to nutrient pollution. Here we assessed the response of soil respiration, an important component of forest carbon budgets, to nutrient enrichment over a wide range of mangrove forests.Methods
We assessed the response of soil respiration to nutrient enrichment using fertilization experiments within 22 mangrove forests over ten sites. We used boosted regression tree (BRT) models to determine the importance of environmental and plant factors for soil respiration and its responsiveness to fertilizer treatments.Results
Leaf area index explained the largest proportion of variation in soil respiration rates (LAI, 45.9 %) followed by those of site, which had a relative influence of 39.9 % in the BRT model. Nutrient enrichment enhanced soil respiration only in nine out of 22 forests. Soil respiration in scrub forests showed a positive response to nutrient addition more frequently than taller fringing forests. The response of soil respiration to nutrient enrichment varied with changes in specific leaf area (SLA) and stem extension, with relative influences of 14.4 %, 13.6 % in the BRT model respectively.Conclusions
Soil respiration in mangroves varied with LAI, but other site specific factors also influenced soil respiration and its response to nutrient enrichment. Strong enhancements in aboveground growth but moderate increases in soil respiration with nutrient enrichment indicated that nutrient enrichment of mangrove forests has likely increased net ecosystem production. 相似文献18.
Hui Li Dandan Ye Xugao Wang Matthew Lee Settles Jun Wang Zhanqing Hao Lisha Zhou Ping Dong Yong Jiang Zhanshan Ma 《Plant and Soil》2014,383(1-2):203-216
Background and aims
The types of natural forests have long been suggested to shape below-ground microbial communities in forest ecosystem. However, detailed information on the impressionable bacterial groups and the potential mechanisms of these influences are still missing. The present study aims to deepen the current understanding on the soil microbial communities under four typical forest types in Northeast Asia, and to reveal the environmental factors driving the abundance, diversity and composition of soil bacterial communities.Methods
Four forest types from Changbai Nature Reserve, representing mixed conifer-broadleaf forest and its natural secondary forest, evergreen coniferous forest, and deciduous coniferous forest were selected for this study. Namely, Broadleaf-Korean pine mixed forest (BLKP), secondary Poplar-Birch forest (PB), Spruce-Fir forest (SF), and Larch forest (LA), respectively. Soil bacterial community was analyzed using bar-coded pyrosequencing. Nonmetric multidimensional scaling (NMDS) was used to illustrate the clustering of different samples based on both Bray-Curtis distances and UniFrac distances. The relationship between environmental variables and the overall community structure was analyzed using the Mantel test.Results
The two mixed conifer-broadleaf forests (BLKP and PB) displayed higher total soil nutrients (organic carbon, nitrogen, and phosphorus) and soil pH, but a lower C/N ratio as compared to the two coniferous forests (SF and LA). The mixed conifer-broadleaf forests had higher alpha-diversity and had distinct bacterial communities from the coniferous forests. Soil texture and pH were found as the principle factors for shaping soil bacterial diversity and community composition. The two mixed conifer-broadleaf forests were associated with higher proportion of Acidobacteria, Verrucomicrobia, Bacteroidetes, and Chloroflexi. While the SF and LA forests were dominated by Proteobacteria and Gemmatimonadetes.Conclusions
Different natural forest type each selects for distinct microbial communities beneath them, with mixed conifer-broadleaf forests being associated with the low-activity bacterial groups, and the coniferous forests being dominated by the so-called high-activity members. The differentiation of soil bacterial communities in natural forests are presumably mediated by the differentiation in terms of soil properties, and could be partially explained by the copiotroph/oligotroph ecological classification model and non-random co-occurrence patterns. 相似文献19.
Annual variation in soil respiration and its component parts in two structurally contrasting woody savannas in Central Brazil 总被引:1,自引:0,他引:1
Andre Butler Patrick Meir Gustavo Saiz Leandro Maracahipes Beatriz Schwantes Marimon John Grace 《Plant and Soil》2012,352(1-2):129-142
Background and aims
Due to the high spatial and temporal variation in soil CO2 efflux, terrestrial carbon budgets rely on a detailed understanding of the drivers of soil respiration from a diverse range of ecosystems and climate zones. In this study we aim to evaluate the independent influence of vegetation structure and climate on soil CO2 efflux within cerrado ecosystems.Methods
We examine the seasonal and diel variation of soil CO2 efflux, including its autotrophic and heterotrophic components, within two adjacent and structurally contrasting woody savannas in central Brazil.Principle results
We found no significant difference in the annual soil CO2 efflux between the two stands (p?=?0.53) despite a clear disparity in both LAI (p?<?0.01) and leaf litterfall (p?<?0.01). The mean annual loss of carbon from the soil was 17.32(±1.48) Mg C?ha?1 of which approximately 63% was accounted for by autotrophic respiration. The relative contribution of autotrophic respiration varied seasonally between 55% in the wet season to 79% of the total soil CO2 efflux in the dry season. Furthermore, seasonal fluctuations of all the soil respiration components were strongly correlated with soil moisture (R 2?=?0.79–0.90, p?<?0.01).Conclusions
Across these two structurally distinct cerrado stands, seasonal variations in rainfall, was the main driver of soil CO2 efflux and its components. Consequently, soil respiration within these ecosystems is likely to be highly sensitive to any changes in seasonal precipitation patterns. 相似文献20.
Cristina Aponte Luis Matías Victoria González-Rodríguez Jorge Castro Luis V. García Rafael Villar Teodoro Marañón 《Plant and Soil》2014,380(1-2):57-72