共查询到20条相似文献，搜索用时 15 毫秒
1.
T. Domisch M. Ohashi L. Finér A. C. Risch L. Sundström J. Kilpeläinen P. Niemelä 《Biology and Fertility of Soils》2008,44(3):539-545
Wood ants (Formica rufa group) are dominating ecosystem elements of the boreal region due to their wide and abundant occurrence. They collect and
concentrate organic material from the surrounding forest floor by building large above-ground mounds. These mounds have higher
temperature and lower water content than the surrounding forest floor. We studied how these peculiar environmental conditions
affected mass loss and carbon (C), nitrogen (N), phosphorus (P) and potassium (K) mineralisation of organic matter in boreal
Norway spruce (Picea abies L. Karst.)-dominated mixed forest stands of four different age classes (5-, 30-, 60-, and 100-year-old) situated in eastern
Finland using the litter bag technique. Norway spruce needle litter was incubated in inhabited and abandoned wood ant mounds
as well as on the surrounding forest floor. We expected decomposition to be extremely slow due to the dryness of the mounds.
Mass losses inside inhabited mounds were lower compared to the surrounding forest floor (on average 30 vs 50% after 2 years)
but not as low as we expected, which might be a result of ant and microbial activity in the mounds. Decomposition in the abandoned
mounds proceeded similarly as on the forest floor. Nutrient mineralisation proceeded more slowly in the ant mounds than on
the surrounding forest floor. Mineralisation occurred for all studied nutrients in the ant mounds, except for N, which net
amount remained stable during the years of the experiment. When wood ant mounds are abandoned and their porous and dry structure
is no longer maintained by the ants, their decomposition is accelerated, and nutrients may be available for uptake by plants,
although the nutrient mineralisation seems still to remain lower compared to the surrounding forest floor. However, eventually
the mound material will be decomposed and nutrients mineralised, thus providing a nutrient hot spot increasing the heterogeneity
of forest floor nutrient availability. 相似文献
2.
The aim of this field experiment was to quantify the contribution of soil fauna to plant litter decomposition in three forest sites differing in C/N ratio under natural conditions in Xishuangbanna, southwestern China. We conducted a survey of soil fauna communities, the forest floor litter and investigated mass loss of mixed tree species leaf litter for two years in a tropical secondary forest, an evergreen broad-leaf forest and a tropical rain forest. Exclusion treatments of different sized soil fauna from the leaf litter by using varying mesh size litter bags (2 mm and 0.15 mm) were also performed. Mass loss and C and N concentrations in litter bag leaf materials were determined at monthly intervals. We found that: (1) the three forests differed in floor litter biomass and nutrient contents but not in soil fauna richness and abundance; (2) litter mass loss and decomposition rate were slower when soil macrofauna and most of mesofauna were excluded; and (3) greatest soil fauna contribution to plant litter decomposition occurred in the rain forest, where leaf litter C/N ratio was also highest (41.5% contribution: 54.8 C/N ratio), in comparison to 8.69% in the broad-leaf forest and 19.52% in the secondary forest, both with low leaf litter C/N ratios (<32). Our results suggested that, soil fauna played a more pronounced role in the decomposition of mixed leaf litter in tropical rain forest, and significantly bigger effects from fauna were ascribed to the enhancement of N concentration and decrease of C concentration of the initially high C/N ratio litter in this forest site. 相似文献
3.
Biochar addition to soil has been generally associated with crop yield increases observed in some soils, and increased nutrient availability is one of the mechanisms proposed. Any impact of biochar on soil organisms can potentially translate to changes in nutrient availability and crop productivity, possibly explaining some of the beneficial and detrimental yield effects reported in literature. Therefore, the main aim of this study was to assess the medium-term impact of biochar addition on microbial and faunal activities in a temperate soil cropped to corn and the consequences for their main functions, litter decomposition and mineralization. Biochar was added to a corn field at rates of 0, 3, 12, 30 tons ha−1 three years prior to this study, in comparison to an annual application of 1 t ha−1.Biochar application increased microbial abundance, which nearly doubled at the highest addition rate, while mesofauna activity, and litter decomposition facilitated by mesofauna were not increased significantly but were positively influenced by biochar addition when these responses were modeled, and in the last case directly and positively associated to the higher microbial abundance. In addition, in short-term laboratory experiments after the addition of litter, biochar presence increased NO2 + NO3 mineralization, and decreased that of SO4 and Cl. However, those nutrient effects were not shown to be of concern at the field scale, where only some significant increases in SOC, pH, Cl and PO4 were observed.Therefore, no negative impacts in the soil biota activities and functions assessed were observed for the tested alkaline biochar after three years of the application, although this trend needs to be verified for other soil and biochar types. 相似文献
4.
Although there has been much recent interest in the effect of litter mixing on decomposition processes, much remains unknown about how litter mixing and diversity affects the abundance and diversity of decomposer organisms. We conducted a litter mixing experiment using litterbags in a New Zealand rainforest, in which treatments consisted of litter monocultures of each of 8 forest canopy and understory plant species, as well as mixtures of 2, 4 and 8 species. We found litter mixing to have little effect on net decomposition rates after either 279 or 658 days, and for each species decomposition rates in mixture treatments were the same as in monoculture. Litter species identity had important effects on litter microfauna, mesofauna and macrofauna, with different litter types promoting different subsets of the fauna. Litter mixing had few effects on densities of mesofauna and macrofauna, but did have some important effects on components of the microfauna, notably microbe-feeding and predatory nematodes. At day 279, litter mixing also consistently reduced the ratio of bacterial-feeding to microbe-feeding (bacterial-feeding+fungal-feeding) nematodes, pointing to mixing causing a significant switch from the bacterial-based to the fungal-based energy channel. Litter mixing sometimes influenced the community composition and diversity of nematodes and macrofauna, but effects of litter mixing on diversity were not necessarily positive, and were much weaker than effects of litter species identity on diversity. We conclude that litter mixing effects on the abundance and diversity of decomposer biota, when they occur, are likely to be of secondary and generally minor significance when compared to the effects of litter species identity and composition. 相似文献
5.
《Pedobiologia》2014,57(4-6):285-291
Invasive plants can disturb interactions between soil organisms and native plants and thereby alter ecosystem functions and/or reduce local biodiversity. Collembola and Acari are the most abundant microarthropods in the leaf litter and soil playing a key role in the decomposition of organic material and nutrient cycling. We designed a field experiment to examine the potential effects of the annual invasive plant Impatiens glandulifera on species diversity, abundance and community composition of Collembola and Acari in leaf litter and soil in a deciduous forest in Switzerland. Leaf litter and soil samples were obtained from plots invaded by I. glandulifera since 6 years, from plots in which the invasive plant had been removed for 4 years and from plots which were not yet colonized by the invasive plant. The 45 leaf litter and soil samples were equally distributed over three forest areas, which were differently affected by a wind throw 12 years prior to sampling representing a natural gradient of disturbance. Collembola species richness and abundance in the leaf litter and soil samples were not affected by the presence of the invasive plant. However, the species composition of Collembola was altered in plots with I. glandulifera. The abundance of leaf-litter dwelling Acari was increased in invaded plots compared to the two other plot types. Furthermore, the presence of the invasive plant shifted the composition of Acari individuals belonging to different groups. Our field experiment demonstrates that an annual invasive plant can affect microarthropods which are important for nutrient cycling in various ecosystems. 相似文献
6.
The litter decomposition, nutrient patterns, as well as nutrient release and soil nutrient contents were determined in response to nitrogen (N) and phosphorus (P) addition and drought treatments following long-term vegetation recovery. The litter decomposition rate decreased with vegetation recovery, due to changes in litter quality, soil nutrient availability, and soil enzyme activity. Nitrogen addition promoted litter decomposition in the early recovery stages but inhibited decomposition in the later stages, indicating a shift in the nutrient limitations to litter decomposition with succession. Neither N nor P addition had any effect on the release of litter carbon (C), whereas N addition inhibited litter N release. In addition, drought decreased litter decomposition and nutrient release during the vegetation recovery process. Our findings suggest that litter quality, soil nutrient availability, and moisture at different vegetation recovery stages should be considered when modeling the C cycle and nutrient dynamics in these ecosystems. 相似文献
7.
Forest management practices often generate clear-cut patches, which may be colonized by ants not present in the same densities in mature forests. In addition to the associated changes in abiotic conditions ants can initiate processes, which do not occur in old-growth stands. Here, we analyse the effects of ants and aphid honeydew on litter solution of Norway spruce, microbial enzyme activities, and needle decomposition in a field and greenhouse experiment during summer 2003. In the field, low ant densities had relatively little effects on litter solution 30 cm away from a tree trunk, but significantly increased organic carbon concentrations and decreased inorganic nitrogen concentrations next to a trunk where ants tend to build their nests. In a greenhouse experiment, the addition of ants to lysimeters containing spruce litter significantly increased dissolved organic carbon (DOC), dissolved organic nitrogen (DON), NH4-N, NO3-N and K concentrations in litter solutions compared to the control treatment, while the simulation of aphid infestation (addition of honeydew) significantly increased DOC as a direct result of honeydew leaching, and decreased inorganic N concentrations in leachates. The presence of ants resulted in a changed composition of dissolved organic matter (DOM) with more aromatic and complex compounds, and microbial enzyme activity was significantly higher in litter extracts from the ant treatment compared to the honeydew and control treatment. However, mass loss, litter %C and %N were not affected by ants or honeydew. Our results suggest that ants have a distinct and immediate effect on solution composition and microbial activity in the litter layer indicating accelerated litter decay whereas the effect of honeydew was insignificant. 相似文献
8.
Home-field advantage of litter decomposition and nitrogen release in forest ecosystems 总被引：1，自引：0，他引：1
Litter decomposition is a major fundamental ecological process that regulates nutrient cycling, thereby affecting net ecosystem carbon (C) storage as well as primary productivity in forest ecosystems. Litter decomposes in its home environment faster than in any other environment. However, evidence for this phenomenon, which is called the home-field advantage (HFA), has not been universal. We provide the first HFA quantification of litter decomposition and nutrient release through meta-analysis of published data in global forest ecosystems. Litter mass loss was 4.2 % faster on average, whereas nitrogen (N) release was 1.7 % lower at the home environment than in another environment. However, no HFA of phosphorus (P) release was observed. Broadleaf litter (4.4 %) had a higher litter mass loss HFA than coniferous litter (1.0 %). The positive HFA of N release was found in the coniferous litter. Mass loss HFA was significantly and negatively correlated with the initial lignin:N litter ratio. The litter decomposition and N release HFAs were obtained when mesh size ranged from 0.15 mm to 2.0 mm. The HFA of litter decomposition increased with decomposition duration during the early decomposition stage. The HFA of N release was well correlated with mass loss, and the greatest HFA was at mass loss less than 20 %. Our results suggest that the litter decomposition and N release HFAs are widespread in forest ecosystems. Furthermore, soil mesofauna is significantly involved in the HFA of litter decomposition. 相似文献
9.
Simoneta Negrete-Yankelevich Carlos Fragoso Adrian C. Newton Graham Russell O. William Heal 《Biology and Fertility of Soils》2008,44(6):853-861
This paper presents the results of a decomposition experiment performed in a secondary chronosequence of tropical montane cloud forest in Mexico. The experiment was designed to explore whether the age of the forest influences the decomposition process and macroinvertebrate community independently of the quality of the decomposition resources. Fresh Pinus chiapensis needles and Persea americana leaves were set to decompose in each of four successional stages (15, 45, 75 and 100 years old). Results do not support the hypothesis that decomposition rate declines with increasing nutrient deficiency as forest succession proceeds. However, the chemical composition in decomposing leaves differed between successional stages. Higher availability of Ca in the 15-year-old forest appears to promote a positive feedback in the release of this nutrient from Persea americana leaves. Additionally, in old forests, a soil community that is more capable of breaking down recalcitrant material (acid detergent lignin) appears to have developed compared to early successional stages. The diversity of macroinvertebrates and abundance of predatory (Aranea and Diplura), detrivorous (Diplopoda) and geophagous (Enchytaeidae) taxa were different between boxes placed in different successional stages. We conclude that the decomposition and associated biota differ between successional stages. Apart from differences in litter quality, other factors associated with the age of the forest, such as small differences in soil temperature and long-lasting effects of disturbance, may also play influential roles. 相似文献
10.
11.
《Applied soil ecology》2007,37(2-3):156-163
Wood ants (Formica rufa group) are ubiquitous in European boreal forests and their large long-lived mound nests, which mainly consist of forest litter and resin, accumulate carbon (C) and nutrients. The C and nutrient dynamics of wood ant mounds in response to forest succession have received minor attention in boreal forests. We aimed to study whether the C, nitrogen (N) and phosphorus (P) concentrations and the bulk density of ant mounds differ from those of the surrounding forest soil, to estimate the C, N and P pools in ant mounds, and to test whether the concentrations and pools change with forest age. Norway spruce (Picea abies (L.) Karst.) stands on medium-fertile sites in 5-, 30-, 60- and 100-year stand age classes were studied in eastern Finland. Carbon and P concentrations in the above-ground mound material were higher than those in the surrounding organic layer. The C, N and extractable P concentrations were higher in the soil under the ant mounds than in the surrounding mineral soil (0–21 cm). The low bulk densities in the ant mounds and the soil below them could be a result of the porous structure of ant mounds and the soil-mixing activities of the ants. The C/N ratios were higher in the mounds than in the organic layer. Carbon concentrations in the ant mounds increased slightly with stand age. Carbon, N and P pools in the ant mounds increased considerably with stand age. Carbon, N and P pools in ant mounds were <1% of those in the surrounding forest soil. Nevertheless, the above- and belowground parts of the ant mounds contained more C, N and P per sampled area than the surrounding forest soil. Wood ants therefore increase the spatial heterogeneity in C and nutrient distribution at the ecosystem level. 相似文献
12.
We conducted a study to determine why the pH of wood ant nest materials is typically higher than that of the surrounding forest soil. An experiment with litter bags demonstrated that the pH of litter increased significantly (after only 7 months) in ant nests. Because the food that foraging ants bring into the nest contains easily decomposed carbohydrates and basic cations (largely in the form of honeydew and prey) that can cause increases in pH, we then estimated the amount of this influ of basic cations and easily decomposed carbohydrates. Based on these estimates, we conducted a second experiment to determine whether addition of field-determined quantities of an easily decomposed carbohydrate (glucose) or a basic cation (Ca2+) would increase the pH of the litter in artificial ant nests in the forest. Both glucose and Ca2+ additions significantly increased the pH of the litter but the increase was greater with Ca2+. The rate of pH increase in the artificial nests was similar to the rate of increase in natural nests. According to our study, ants collect substantial amounts of mineral-enriched materials in this ecosystem, which collectively increase the pH of nest material. 相似文献
13.
《European Journal of Soil Biology》1999,35(2):57-63
This study was carried out in a tropical hill evergreen forest in northern Thailand. Two tree species Castanopsis accuminatissima and Schima wallichii were the dominant species in the study plot. Decomposition processes of these two species were studied using a litter bag method to evaluate the roles of these species in the nutrient cycling in this hill evergreen forest. The decomposition rates (k) were 0.99–1.05 and 0.55–0.61 in C. accuminatissima and S. wallichii, respectively. In this monsoon forest, the relationship between the onset of rain and the accumulation and decomposition of litter is an important mechanism for linking climate and availability of plant nutrient. Weight loss for both species showed a similar pattern shaped by the seasonal availability of water. However, the nitrogen dynamics were apparently different in the two species. During the rainy season, C. accuminatissima released nitrogen during the decomposition processes, while S. wallichii nitrogen was immobilized in the leaf litter over the rainy season. C. accuminatissima released nitrogen, subsequently available for uptake by trees, while S. wallichii accumulated nitrogen over 15 months and so their roles are important for the retention of nutrients in the hill evergreen forest ecosystem. Thus the two species have different functions in the nutrient dynamics in the forest floor. 相似文献
14.
Douglas T. Bolger 《Biological conservation》2007,136(2):295-305
One consequence of human land-use is the exposure of native communities to invasive human commensal species along edges. Argentine ants (Linepithema humile) invade a variety of habitats in California with consequent dramatic declines in native ants. In coastal southern California, USA Argentine ants appear to be an edge effect in small habitat fragments [Suarez, A.V., Bolger, D.T., Case, T.J., 1998. Effects of fragmentation and invasion on native ant communities in coastal southern California. Ecology 79, 2041-2056]. They invade fragments from the urban edge, but only penetrate coastal sage scrub (CSS) habitat to a distance of approximately 200 m. Using pitfall sampling in edge (<250 m from the urban edge) and interior (>600 m from the edge) habitat I tested whether there is also an Argentine ant edge effect in the largest blocks of habitat in the landscape and investigated patterns of spatial and temporal variation in native and Argentine ants. Argentine ants were common in coastal sage scrub habitat within 250 m of urban edges, but rare in interior areas. Correspondingly, native ants were significantly less abundant and diverse in edge areas as compared to interior. Over the period 1997-2000 Argentine ants did not become more abundant in interior habitat suggesting it will remain a refuge for native ants. Argentine ant abundance in edge plots varied greatly among years and sites. Annual variation in abundance was positively related to annual rainfall. Increased soil moisture near edges due to urban runoff has often been suggested as the mechanism that allows the invasion of edge but not interior habitat. This hypothesis predicts that edge habitat downslope of the urban edge should support invasions of higher abundance and greater spatial penetration than habitat upslope. However, I found that edge slope did not predict the extent of invasion, whereas, soil type did. Coarse, well-drained soils supported an Argentine ant invasion of lower abundance and lesser spatial penetration than soils that should retain more moisture. These patterns of spatial and annual variation are more consistent with a biotic flow mechanism where ants move from urban habitat into CSS sites that are temporarily favorable, rather than an abiotic flow where urban runoff causes a physical change to CSS habitat near edges. This invasion affects a substantial area of habitat, however, the inability of Argentine ants to invade interior habitat suggests that refugia for native ants will persist if large unfragmented blocks of habitat are maintained. 相似文献
15.
Yan Weiming Zhong Yangquanwei Zhu Guangyu Liu Wenzhao Shangguan Zhouping 《Journal of Soils and Sediments》2020,20(4):1858-1868
Purpose
Understanding ecosystem processes such as litter decomposition in response to dramatic land-use change is critical for modeling and predicting carbon (C) cycles. However, the patterns of litter decomposition along with long-term secondary succession (over 100 years) are not well reported, especially concerning nutrient limitations on litter decomposition.
Materials and methodsTo clarify the response of litter decomposition to changes in soil nutrient availability, we conducted four incubation experiments involving soil and litter and nutrient addition from different successional stages and investigated the changes in microbial respiration and litter mass loss.
Results and discussionOur results revealed that microbial respiration increased with succession without any litter addition (1.19~1.73 mg C g?1 soil), and litter addition significantly promoted microbial respiration (16.5~72.9%), especially in the early successional stage (grassland and shrubland). The decomposition rate of the same litter decreased with succession. In addition, nitrogen (N) and phosphorus (P) addition showed significant effects on litter decomposition and microbial respiration; P addition promoted litter decomposition (2.4~15.3%) and microbial respiration (10.1~34.5%) in all successional stages, while N addition promoted litter decomposition (4.0~10.3%) and microbial respiration (5.4~27.2%) in all except the last stage of succession, which showed a negative effect on litter decomposition (??7.5%) and microbial respiration (??6.1%), indicating possible N saturation of litter decomposition and microbial respiration.
ConclusionsThis work highlights that soil nutrient availability and successional stages need to be taken into account to predict the changes to litter decomposition in response to global changes.
相似文献16.
17.
In contrast to the body of work in more mesic habitats, few studies have examined boundary processes between natural and anthropogenic desert landscapes. Our research examined processes occurring at boundaries between a desert sand dune community and an encroaching suburban habitat. We measured responses to an anthropogenic boundary by species from multiple trophic levels, and incorporated measures of habitat suitability, and temporal variation, at multiple spatial scales. At an edge versus core habitat scale the only aeolian sand species that demonstrated an unambiguous negative response to the anthropogenic habitat edges was the flat-tailed horned lizard (Phrynosoma mcallii). Conversely loggerhead shrikes (Lanius ludovicianus) demonstrated a positive response to that edge. At a finer scale, species that exhibited a response to a habitat edge within the first 250 m included the horned lizards along with desert kangaroo rats (Dipodomys deserti). The latter species’ response was confined to 25 m from the edge. For the flat-tailed horned lizard, edge effects were measured up to 150 m from the habitat boundary. Three potential causal hypotheses were explored to explain the edge effect on horned lizards: (1) invasions of exotic ant species reducing potential prey for the lizards; (2) road avoidance and road associated mortalities; and (3) predation from a suite of avian predators whose occurrence and abundance may be augmented by resources available in the suburban habitat. We rejected the exotic ant hypothesis due to the absence of exotic ants within the boundary region, and because native ant species (prey for horned lizards) did not show an edge effect. Our data supported the predation and road mortality hypotheses. Mechanisms for regulating population dynamics of desert species are often “bottom-up,” stochastic processes driven by precipitation. The juxtaposition of an anthropogenic edge appears to have created a shift to a “top-down,” predator-mediated dynamic for these lizards. 相似文献
18.
Elvira Sereda Theo Blick Wolfgang H.O. Dorow Volkmar Wolters Klaus Birkhofer 《Pedobiologia》2012,55(5):241-245
Describing the biotic and abiotic processes that are responsible for the formation of spatial patterns in predators and their prey is crucial for improving our understanding of food–web interactions. We studied the spatial distribution of four abundant spider species and three common groups of epedaphic Collembola prey in a beech-dominated (Fagus sylvatica) forest floor habitat and related the observed patterns to environmental heterogeneity, overall predator activity (all ground beetles and spiders) and prey availability (all Collembola) at the local scale. Spiders and epedaphic Collembola were sampled over 392 days in a spatially explicit design based on a regular grid of 25 pitfall traps (inter-trap distance 100 m). Environmental heterogeneity was characterized by cover of moss and litter as well as the amount of dead wood at each trap location. We first used the index of dispersion to characterize the spatial distribution of spider species and Collembola and then related the observed patterns to environmental heterogeneity, predator and prey availability while testing for spatial autocorrelation within the same models. All taxa were significantly more aggregated than expected from the assumption of random distribution. The distribution of spider species was positively (Coelotes terrestris) or negatively (Tenuiphantes zimmermanni and Tapinocyba insecta) related to the cover of moss and negatively related to litter cover (C. terrestris) or the local availability of prey (T. insecta). The distribution of Collembola was negatively related to local litter cover (Lepidocyrtus spp.) and positively related to the amount of medium deadwood pieces (all other Entomobryidae). Our study suggests that none of the spider species preferred areas of low overall predator activity density. Moreover, it does not indicate association of spider species to prey-rich areas at the analyzed scale of 100 m. It further highlights the importance of environmental heterogeneity, as different habitat properties differentially affected the local activity density of spiders and Collembola and thus considerably contributed to the understanding of distribution patterns. 相似文献
19.
Effect of soil carbohydrates on nutrient availability in natural forests and cultivated lands in Sri Lanka 总被引：1，自引：0，他引：1
Carbohydrates supply carbon sources for microbial activities that contribute to mineral nutrient production in soil. Their role on soil nutrient availability has not yet been properly elucidated. This was studied in forests and cultivated lands in Sri Lanka. Soil organic matter (SOM) fractions affecting carbohydrate availability were also determined. Soil litter contributed to sugars of plant origin (SPO) in croplands. The negative relationship found between clay bound organic matter (CBO) and glucose indicates higher SOM fixation in clay that lower its availability in cultivated lands. In forests, negative relationships between litter and sugars of microbial origin (SMO) showed that litter fuelled microbes to produce sugars. Fucose and glucose increased the availability of Cu, Zn and Mn in forests. Xylose increased Ca availability in cultivated lands. Arabinose, the main carbon source of soil respiration reduced the P availability. This study showed soil carbohydrates and their relationships with mineral nutrients could provide vital information on the availability of limiting nutrients in tropical ecosystems. 相似文献
20.
为研究火烧迹地雷竹(Phyllostachys violascens)凋落叶分解过程中土壤动物群落特征,以毗邻雷竹林为对照,采用凋落物袋法研究雷竹凋落叶分解速率及土壤动物群落结构的变化特征。结果显示,两个样地雷竹凋落叶分解过程总体上可以划分为3个阶段,即分解初期(质量损失率较高)、分解中期(凋落叶的质量损失率较上阶段减缓)、分解后期(质量损失率再次上升)。调查共捕获土壤动物824只,其中火烧迹地375只,对照样地449只,以绥螨科、蚁科、线虫纲和等节(虫兆)科为优势类群,所占百分比为49.27%,火烧迹地土壤动物类群数变化幅度较个体数小。统计分析表明,火烧迹地和对照样地凋落叶分解过程中土壤动物类群数无显著差异(P0.05)。两个样地土壤动物均匀度指数、多样性指数和丰富度指数均呈上升趋势,而优势度指数则逐渐降低,凋落叶分解过程中土壤动物个体数、类群数均与降水量存在显著相关关系(P0.05)。主坐标分析(PCoA)表明,凋落叶分解初期受火烧干扰较大,后期受分解时间累积效应影响较大。试验表明,火烧干扰延缓了雷竹凋落叶的分解速率,但随着时间的延续,火烧迹地雷竹叶分解速率则迅速提升,土壤动物群落也得到恢复。 相似文献