Litter Arthropods Research Articles

Litter arthropod communities in a Northeastern Cerrado area of Maranhão state, Brazil

Litter arthropod communities in a Northeastern Cerrado area of Maranhão state, Brazil

Molecular diversity of Diplura in southern High Appalachian leaf litter.

The fauna of Diplura, the two-pronged bristletails (Hexapoda), of the southern Appalachians has received little focused systematic attention. Existing literature suggests the fauna to comprise around a dozen species. Based on a broader DNA barcode-based survey of high elevation litter arthropods in the region, we suggest the fauna to be much richer, with automated species delimitation methods hypothesising as many as 35 species, most highly restricted to single or closely proximate localities. Such a result should not be very surprising for such small, flightless arthropods, although it remains to be seen if other markers or morphology support such high diversity. The region still remains sparsely sampled for these more cryptic elements of the arthropod fauna and much larger numbers of species undoubtedly remain to be discovered.

Most soil and litter arthropods are unidentifiable based on current DNA barcode reference libraries.

We are far from knowing all species living on the planet. Understanding biodiversity is demanding and requires time and expertise. Most groups are understudied given problems of identifying and delimiting species. DNA barcoding emerged to overcome some of the difficulties in identifying species. Its limitations derive from incomplete taxonomic knowledge and the lack of comprehensive DNA barcode libraries for so many taxonomic groups. Here, we evaluate how useful barcoding is for identifying arthropods from highly diverse leaf litter communities in the southern Appalachian Mountains (USA). We used 3 reference databases and several automated classification methods on a data set including several arthropod groups. Acari, Araneae, Collembola, Coleoptera, Diptera, and Hymenoptera were well represented, showing different performances across methods and databases. Spiders performed the best, with correct identification rates to species and genus levels of ~50% across databases. Springtails performed poorly, no barcodes were identified to species or genus. Other groups showed poor to mediocre performance, from around 3% (mites) to 20% (beetles) correctly identified barcodes to species, but also with some false identifications. In general, BOLD-based identification offered the best identification results but, in all cases except spiders, performance is poor, with less than a fifth of specimens correctly identified to genus or species. Our results indicate that the soil arthropod fauna is still insufficiently documented, with many species unrepresented in DNA barcode libraries. More effort toward integrative taxonomic characterization is needed to complete our reference libraries before we can rely on DNA barcoding as a universally applicable identification method.

Shedding light on dark taxa in sky‐island Appalachian leaf litter: Assessing patterns of endemicity using large‐scale, voucher‐based barcoding

Abstract Developing systematic conservation plans depends on a wealth of information on a region's biodiversity. For ‘dark taxa' such as arthropods, such data are usually very incomplete and in most cases left out from assessments. Sky islands are important and often fragile biodiversity hotspots. Southern Appalachian high‐elevation spruce–fir forests represent a particularly threatened sky‐island ecosystem, hosting numerous endemic and threatened species, but their arthropods remain understudied. Here we use voucher‐based megabarcoding to explore genetic differentiation among leaf‐litter arthropod communities of these highlands, and to examine the extent to which they represent dispersed communities of more or less coherent species, manageable as a distributed unit. We assembled a dataset comprising more than 6000 COI sequences representing diverse arthropod groups to assess species richness and sharing across peaks and ranges. Comparisons were standardised across taxa using automated species delimitation, measuring endemism levels by putative species. Species richness was high, with sites hosting from 86 to 199 litter arthropod species (not including mites or myriapods). Community profiles suggest that around one fourth of these species are unique to single sky islands and more than one third of all species are limited to a particular range. Across major taxa, endemicity was lowest in Araneae, and highest in neglected groups like Isopoda, Pseudoscorpionida, Protura and Diplura. Southern Appalachian sky islands of spruce–fir habitat host significantly distinct leaf‐litter arthropod communities, with high levels of local endemicity. This is the first work to provide such a clear picture of peak and range uniqueness for a taxonomically broad sample. Ensuring the protection of a sizeable fraction of high‐elevation litter species richness will therefore require attention at a relatively fine spatial scale.

Alteration of a temperate forest invertebrate community by invasive Japanese barberry (Berberis thunbergii) has limited influence on the diet composition of territorial ovenbirds (Seiurus aurocapilla)

Invasive species are widely implicated in the decline of songbird populations, potentially via indirect effects such as the restructuring of ecological communities by non-native plants. We used stable isotope analysis to investigate whether ground-foraging, generalist insectivore ovenbirds ( Seiurus aurocapilla (Linnaeus, 1766)) shifted diets following invasion by a non-native shrub, Japanese barberry ( Berberis thunbergii DC.), in a temperate woodland system in New York, USA where barberry was previously linked to trophic downgrading in the leaf litter arthropod community. Assimilated ovenbird diets were primarily composed of predatory invertebrates followed by sucking herbivores, chewing herbivores, and detritivores. The only notable changes in assimilated ovenbird diets were a modest 14.7% decrease in chewing herbivore contributions and a minor 7.0% increase in sucking herbivore contributions in forest patches with high barberry densities. Our results indicate that the effects of non-native plants on connections between higher trophic levels are context-dependent, and comparisons with other studies suggest that community complexity and time since introduction are key contextual differences that affect the outcome of an invasion. Our results may reflect compensatory shifts in individual foraging effort by ovenbirds, but, in combination with our previous research, provide little evidence that barberry affects ovenbird condition and therefore downstream outcomes.

Leaf litter arthropods show little response to structural retention in a Central European forest

Decomposition of leaf litter is a central process of energy and nutrient cycling in forests, in which arthropods hold important roles. Thus, safeguarding the diversity of organisms including arthropods is increasingly being considered in contemporary forestry, not least to facilitate continued ecosystem functioning. Retention forestry tries to achieve biodiversity conservation by preservation of tree structural elements such as deadwood and tree microhabitats to provide more heterogeneous habitat. Leaf litter arthropods are, however, only indirectly connected with tree structure, which raises the question if and how the currently practised retention forestry influences the leaf litter arthropod community. As the leaf litter arthropod community includes a very diverse range of taxa that is challenging to identify morphologically, we sampled environmental DNA from leaf litter on 66 plots in the Black Forest in southern Germany that were distributed over gradients of forest and landscape features and differed in forest management intensity. We found that the richness of operational taxonomic units, a surrogate for species, was not related to forest structure but tended to increase with recent harvest intensity (which did not exceed a medium harvest intensity on our plots). Community composition was related to the share of coniferous trees present on a plot, and to a lesser extend to elevation and leaf litter coverage. Our results indicate that the leaf litter arthropod community is not responsive towards different degrees of forest structural changes introduced by management as long as the forest type is retained.

Transitional morphology and Afrotropical affinity of a bythinoplectine rove beetle from the early Eocene of India (Coleoptera: Staphylinidae: Pselaphinae)

Recently discovered Ypresian-age amber from Cambay, India, reveals an ancient arthropod assemblage on the Indian subcontinent during its collision with Asia. Despite the tectonic history of India, limited connections have been found between the Cambay palaeofauna and present-day Madagascan and mainland African faunas. Here, I describe a new fossil pselaphine rove beetle (Staphylinidae: Pselaphinae) recovered from the Cambay deposit that shows closest apparent phylogenetic affinity to modern Afrotropical genera. Yprezethinus grimaldii gen. et sp. nov. is placed in Bythinoplectini, subtribe Bythinoplectina. Based on antennal and maxillary palp morphology, Yprezethinus is a putative transitional stem lineage of the Zethinus-group of genera—an extant clade distributed across equatorial African rainforests. Although Yprezethinus shares with this clade the derived feature of ovoid antennal clubs formed by tight appression of the apical two segments, it differs from its putative extant relatives in its possession of the plesiomorphic complement of 11 antennomeres, without any fusions of segments. The fossil taxon signifies a biotic link between early Eocene India and continental Africa, and marks the Cenozoic emergence of a tropical leaf litter arthropod fauna approaching that of contemporary, ant-dominated rainforests.

Arthropod biodiversity in tropical forest litter around Nagpur (Maharashtra)

A study on litter arthropod population was carried out in four tropical dry region distributed in forest areas of Indian state of Maharashtra India. The study was conducted in an around Nagpur, lakeside region and tropical dry region vegetation types. The leaf litter present inside a 1 m2 quadrat was collected, shifted in polythene bags. Total 195 litter arthropods representing 13 insect orders were recorded from the forty unit (15cm x 15cm) samples collected from four tropical region sites viz. (Site 1:- Gorewada lake, Site 2:- Ambazari lake, Site 3:- Futala lake, and Site 4:- Civil line forest). The insect orders, Hymenoptera, Isoptera, Thysanura, and Orthoptera dominated the litter arthropod abundance, and the top five orders contributed 73% of the total litter arthropods collected from all the four tropical dry region of Nagpur, India. The results of this study will initiate future research on litter arthropod population and their diversity and abundance in Nagpur forest.

Landscape acidification has trophic-mediated effects on Ovenbirds (Seiurus aurocapilla)

Acid deposition from fossil fuel combustion caused calcium depletion in eastern North America during the 20th century, and calcium is a critical resource for birds during both the egg laying and nesting periods. The effects of acid deposition on animals have largely acted through trophic relationships, with reduced calcium availability in prey possibly being a limiting factor for forest songbirds. Following 21 years of experimental whole-watershed acidification at the Bear Brook Watershed in Maine, we investigated Ovenbird (Seiurus aurocapilla) territory size and potential prey (leaf litter arthropod) abundance, assemblage, and calcium concentration during one breeding season. We delineated and estimated the area of 8 Ovenbird territories in an acidified and a control watershed, but found that territory size did not differ between watersheds. However, while calcium concentrations of potential prey also did not differ between watersheds, territory size decreased as calcium concentrations of potential prey increased, regardless of watershed. Our results suggest that calcium limitation can be a determinant of territory size in some landscapes, and this provides further support to importance of the role of calcium in the lives of passerines.

Vulnerable Neotropical migratory songbird demonstrates flexibility in space use in response to rainfall change

Abstract Behavioral flexibility of individuals is essential if organisms are to ultimately adapt to climate change. As environmental conditions, such as precipitation patterns become increasingly variable, fine-scale spatiotemporal flexibility in space use may allow for individuals to track resources during periods of adverse or atypical conditions. Individual behavioral flexibility is observable over short timeframes and can therefore be used to assess resilience of a species to projected shifts in climate. The goal of our study was to determine if and how individuals modified their space and habitat use in response to rainfall-driven changes in resources throughout a period of atypical seasonal rainfall patterns. We used radio telemetry to estimate home ranges of nonbreeding Swainson’s Warblers (Limnothlypis swainsonii) in 2 time frames (bi-seasonally and bi-weekly) in Jamaica during dry and wet periods. We measured habitat structure and food (leaf litter arthropod) availability within each home range to determine possible predictors of space use change. Individuals modified the area and/or location of their home ranges with changes in precipitation, and those occupying more open habitats had greater changes in home range area as seasonal rainfall increased. As food increased following rain, individuals constricted their home ranges (bi-weekly) or shifted spatially (bi-seasonally) to a novel area with greater food availability. This suggests individuals are able to rapidly respond to how their environment changes, presumably adjusting to trade-offs between home range size and resource availability. This flexibility may be a key behavioral component in enduring long-term increasingly unpredictable environmental variability and may have population-level consequences. These responses are, however, mediated by habitat, suggesting the ability to respond to variable or poor conditions is not homogeneous across a population.

Shrub facilitative effects on the plant litter arthropod community shifts with decreasing precipitation in desertified ecosystems in northwestern China

Understanding shrub effects on plant litter arthropod community structure in contrasting semiarid and arid grassland ecosystems could lead to the promotion of biodiversity conservation and sustainable management in afforested plantations. An investigation of litter arthropod abundance and diversity beneath the shrub canopy and in open spaces between shrubs was conducted via a litterbag field experiment during two consecutive years in a semiarid and an arid grassland ecosystem. Litter arthropod diversity and abundance were significantly higher in the shrub understory than in open spaces in the arid grassland. Furthermore, a similar abundance of both total mites and predatory mites was found in the shrub understory. However contrasting trends were found in the semiarid grassland. Significantly higher detritivorous mite abundance was found in the open areas between shrubs with no clear facilitation effects on the detritivore community. In conclusion, shrub facilitation could expand biodiversity conservation towards open spaces in extreme arid grasslands. The increasing drought expected for the region under climate change scenarios strengthens the importance of conserving shrub cover in these ecosystems to sustain biodiversity and ecosystem functioning.

半干旱草地植物枯落物碳、氮和磷元素释放对放牧和封育管理的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 半干旱草地植物枯落物碳、氮和磷元素释放对放牧和封育管理的响应 DOI: 10.5846/stxb202104160988 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 宁夏自然科学基金项目（2021AAC03047） Response of C, N and P release dynamics of plant litter to grazing and enclosure management in semiarid grassland ecosystem Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在半干旱草地，关于放牧和封育管理对草地植物枯落物分解及其与土壤动物互作关系的研究一直是该区域生态系统物质循环与生态恢复过程研究的重要科学问题。以放牧和封育样地中赖草（Leymus secalinus）、牛枝子（Lespedeza potaninii）及其混合枯落物为研究对象。于2017年9月、2018年5月和9月、2019年5月和9月，采用2种不同孔径（30目和250目）网袋量化中小型土壤动物的作用，调查了宁夏半干旱草地枯落物碳、氮和磷元素分解与土壤动物群落分布及其对放牧和封育样地的响应规律。结果显示：（1）封育样地中，枯落物碳元素最终残留率均表现为3种枯落物处理间无显著差异；但250目网孔中枯落物氮、磷元素最终残留率和30目网孔中氮元素最终残留率均表现为牛枝子显著高于赖草和混合物，而后两者间无显著差异；仅30目网孔中磷元素最终残留率表现为牛枝子和混合物显著高于赖草，而前两者间无显著差异。放牧样地中，250目网孔的碳、磷元素最终残留率和30目网孔中的氮、磷元素最终残留率均表现为牛枝子显著高于混合物，而赖草居中；氮元素最终残留率表现为牛枝子显著高于赖草和混合物，后两者间无显著差异。（2）土壤动物对枯落物碳、氮和磷元素最终残留率的影响较小；但不同网孔下混合枯落物氮元素最终残留率均表现为放牧显著低于封育样地，而赖草和牛枝子枯落物磷元素残留率均表现为放牧显著高于封育样地，且30目网孔中赖草枯落物氮元素残留率表现为放牧显著高于封育样地。（3） Mantel检验和PCA分析进一步表明，土壤动物多样性分布和土壤理化性质显著影响枯落物碳、氮和磷养分元素释放。研究表明，半干旱草地枯落物碳、氮和磷元素释放受土壤性质和物种化学特性影响，放牧与封育管理通过影响网孔中土壤动物分布来调控植物枯落物碳、氮和磷元素释放。放牧干扰显著弱化土壤-土壤动物-枯落物之间的联系，但同时显著加速了混合枯落物中氮、磷元素的释放。 Abstract:In semi-arid grassland, plant litter decomposition and its interaction with litter arthropods under grazing and enclosure management play implications on material cycling and ecological restoration process. The litter from Leymus secalinus, Lespedeza potaninii, and their mixture were selected as samples, and they were set in situ in Ningxia semi-arid grasslands under enclosure and grazing management. This study probed into the distribution of litter arthropod and its relation to the release of C, N and P contents by using two sizes (30-mesh and 250-mesh) litterbag to quantify the role of small and medium litter arthropod collected in September of 2017, May and September of 2018, as well as May and September of 2019. The results showed that:(1) In the enclosed grassland, there was no significant difference in the final remaining rate of litter C in between L. potaninii, L. secalinus, and mixture; however, there was significantly greater final remaining rate of litter N and P in the 250-mesh, and that of litter N in the 30-mesh in L. potaninii than in L. secalinus and mixture; there was significantly greater final remaining rate of litter P in L. potanini and mixture than in L. secalinus. In the grazed grassland, there was significantly greater final remaining rate of litter C and P in the 250-mesh, and that of litter N and P in the 30-mesh in L. potaninii than in mixture, with intermediate values in L. secalinus. Regarding the final remaining rate of N, there were significantly higher values in L. potaninii than in L. secalinus and mixture, whereas there was no significant difference between L. secalinus and mixture. (2) There was little effect of litter arthropods on the final remaining rate of C, N and P in the three plant treatments. However, there was significantly lower final remaining rate of N in mixture from both 30- and 250 mesh in grazed grassland than in enclosed grassland. There was significantly higher remaining rate of P in L. secalinus in grazed grassland than in enclosed grassland. (3) The Mantel test and principal components analysis indicated a considerable effect of litter arthropods and soil physicochemical properties on the decomposition of litter C, N and P content. It was suggested that litter C, N and P contents were affected by soil properties and plant chemical properties in semi-arid grassland. The effect of grazing management on litter arthropod distribution induced the differences in C, N and P nutrient release between various species of plant litter. The grazing disturbance could weaken the linkage between litter decomposition, arthropod and soil, while in feedback grazing could promote the litter decomposition of N and P content in mixture. 参考文献 相似文献 引证文献

Diet Electivity and Preferences for Food Resources in Chiasmocleis leucosticta (Anura: Microhylidae)

Predator–prey interactions are complex relationships between both participants. Although many food items are available in the environment for a frog, it can choose to feed on one item instead of another, depending on several aspects of the prey, such as size, availability, abundance, mobility, and palatability. In this study we compared the frequency of each food item we observed in stomachs of the frog Chiasmocleis leucosticta with the availability of leaf litter arthropods we collected at the same place and time that of the frogs through Ivlev's electivity index. We verified that the electivity for ants and mites as food items in the diet of the population from Reserva Florestal de Morro Grande is an actual preference. Chiasmocleis leucosticta seems to elect smaller sized genera, such as Solenopsis and Pheidole, and avoid bigger and more aggressive ants, such as Pachycondyla, Camponotus, and Odontomachus. Also, we suggest that for C. leucosticta or even for other Microhylidae there is reason to believe that alkaloids are obtained as part of the diet; related studies on the biochemistry of this family, genus, and species are encouraged.

Elevation and leaf litter interact in determining the structure of ant communities on a tropical mountain

AbstractTropical mountains encompass a wide range of environmental conditions and are useful models for studying drivers of community structure. Invertebrate species richness and abundance show various elevational patterns. However, the drivers of these differences are not well understood, although microhabitat complexity is potentially important. We studied ground‐dwelling ants using pitfall trapping and hand collection on Mt. Wilhelm (Papua New Guinea) from 169 to 3,795 m a. s. l. We tested for the effects of elevation and leaf litter depth (as a measure of microhabitat complexity) on ant abundance, species richness, and composition. We sampled 118 species, with ants present up to 2,331 m a. s. l. Species richness peaked at mid‐elevation (~700 m), but the elevational pattern for abundance varied depending on sampling scale. Leaf litter depth negatively affected abundance once elevation had been accounted for, while elevation and litter depth had an interactive effect on species richness. Species richness was positively related to litter depth at lower elevations, but negatively above ~ 700 m. Species composition varied with elevation and less strongly with leaf litter depth. We speculate that in the lowlands, litter depth rather than temperature limits ant communities. At high elevations, the deeper litter decreases temperature of the litter layer, and temperature becomes limiting. At mid‐elevations, temperature is not yet too low, and litter is still relatively deep, hence generating a mid‐elevation peak in ant richness. Our results may explain differing richness‐elevation patterns of litter arthropods around the world and provide testable predictions for future studies on this topic.

Rapid toxin sequestration modifies poison frog physiology.

Poison frogs sequester chemical defenses from their diet of leaf litter arthropods for defense against predation. Little is known about the physiological adaptations that confer this unusual bioaccumulation ability. We conducted an alkaloid-feeding experiment with the Diablito poison frog (Oophaga sylvatica) to determine how quickly alkaloids are accumulated and how toxins modify frog physiology using quantitative proteomics. Diablito frogs rapidly accumulated the alkaloid decahydroquinoline within 4 days, and dietary alkaloid exposure altered protein abundance in the intestines, liver and skin. Many proteins that increased in abundance with decahydroquinoline accumulation are plasma glycoproteins, including the complement system and the toxin-binding protein saxiphilin. Other protein classes that change in abundance with decahydroquinoline accumulation are membrane proteins involved in small molecule transport and metabolism. Overall, this work shows that poison frogs can rapidly accumulate alkaloids, which alter carrier protein abundance, initiate an immune response, and alter small molecule transport and metabolism dynamics across tissues.

Litter arthropods community in multifunctional landscapes: Spatial and temporal complementarity of Brazilian ecosystems

In view of the heterogeneity of ecosystems that make up the Cerrado biome, frequent replacement of native vegetation by exotic components and typically seasonal climate, the present study aimed to investigate: (1) How litter arthropods communities are distributed in time and space in a multifunctional landscape in Cerrado biome, and (2) the importance of natural and anthropized ecosystems for the litter arthropod community in the dry and rainy seasons. The research was carried out in 12 sites in the Triângulo Mineiro region, state of Minas Gerais, Brazil. The study area is part the Cerrado biome and, of the 12 sites, three were composed of fragments of cerrado sensu stricto (s.s.), three by abandoned pastures, three by veredas and three by eucalypt plantation. The collection of litter arthropods occurred through pitfall traps in the dry and rainy seasons. The individuals collected were identified at the family level and categorized according to the trophic function and body size. Although the different ecosystems in isolation did not influence the quantitative parameters of arthropod communities, an important interaction between ecosystems and seasonality was observed. During the rainy season the litter arthropod communities in cerrado s.s. and veredas presented similar richness with slightly greater Simpson diversity in the cerrado s.s., but the veredas were much richer and diverse than other ecosystems in the dry season. A high diversity was also observed in the eucalypt plantations in the rainy season, but with a low functional richness. The functional and taxonomic compositions of the litter arthropod communities differed among ecosystems. In addition, even with a high richness in anthropized ecosystems, the communities present in the savannas were not similar to those present in anthropized ecosystems. Therefore, it was observed that the litter arthropod communities formed spatial and temporal mosaics that play complementary roles in supporting litter arthropod biodiversity.

Crazy ants craving calcium: macronutrients and micronutrients can limit and stress an invaded grassland brown food web.

Nitrogen and phosphorus are thought to be the most important limiting nutrients in most terrestrial ecosystems, but little is known about how other elements may limit the abundance of arthropods. We utilized a fully factorial fertilization experiment that manipulated macronutrients (N and P, together) and micronutrients (calcium, sodium, potassium, separately), in large 30×30m plots and sampled litter arthropods via pitfall trapping to determine the nutrients that limit this group. An invasive ant, Nylanderia fulva, numerically dominated the community and increased in abundance 13% in plots fertilized by Ca. Detritivores were not limited by any nutrient combination, but macronutrients increased predator abundance 43%. We also found that some combinations of macronutrients and micronutrients had toxic or stressful effects on the arthropod community: detritivores decreased in abundance 23% with the combination of macronutrients, Ca, and K, and 22% with macronutrients and K; and N. fulva decreased in abundance 24% in plots fertilized by K and 45% in plots fertilized by the combination of Na and K. Our work supports growing evidence that micronutrients, especially Ca and K, may be important in structuring grassland arthropod communities, and suggests that micronutrients may affect whether or not invasive ants reach numerical dominance.

半干旱草地不同植物枯落物分解对放牧和封育的响应

为探究放牧和封育对半干旱草地植物枯落物分解的影响，选取赖草、牛枝子及其混合物为研究对象，调查了不同网孔分解袋中宁夏半干旱草地植物枯落物分解特征及对放牧和封育的响应规律。结果表明：（1）放牧样地250目网孔中，枯落物质量残留率表现为牛枝子显著高于赖草和混合物（P<0.05），而在放牧样地30目网孔、封育样地2种网孔中，枯落物质量残留率均表现为3种枯落物间无显著差异。（2）250目网孔中，放牧和封育样地枯落物分解衰减常数均表现为混合物显著高于牛枝子，而赖草居中；并且，牛枝子枯落物分解衰减常数表现为封育样地显著高于放牧样地。30目网孔中，放牧和封育样地枯落物分解衰减常数均表现为赖草、混合物显著高于牛枝子（P<0.05）；并且，牛枝子枯落物分解衰减常数表现为封育样地显著高于放牧样地（P<0.05）。（3）在放牧样地，仅牛枝子枯落物R_m表现为30目显著低于250目网孔（P<0.05），k表现为30目显著高于250目网孔（P<0.05）；土壤动物对枯落物分解的贡献率表现为混合物显著低于牛枝子，赖草居中（P<0.05）。而在封育样地，仅牛枝子枯落物k表现为30目显著高于250目网孔（P<0.05）；土壤动物对枯落物分解的贡献率表现为混合物和牛枝子均显著高于赖草，且混合枯落物的土壤动物贡献率表现为封育样地显著高于放牧样地（P<0.05）。（4）枯落物残留率与其初始N、P、木质素/N、C/P呈显著相关性（P<0.05）；枯落物分解衰减常数与其初始N、P、木质素、N/P、C/P和木质素/P间均呈显著相关性（P<0.05）。研究表明，植物种类组成显著影响枯落物的残留率和分解衰减常数。放牧与封育管理通过影响网孔中土壤动物分布来调控半干旱区草地植物枯落物的分解，而且封育管理更有利于促进土壤动物对低质量枯落物（牛枝子）的分解。;This present study was to explored litter decomposition of different plant species under grazing and enclosure management in semi-arid grassland ecosystems. The remaining mass and decay constant (k) of Leymus secalinus, Lespedeza potaninii litter, and their mixture were investigated within 30-and 250-mesh litterbags in semiarid grasslands under grazing and enclosure management in Ningxia. In addition, the contribution of litter arthropods to decomposition was analyzed in order to discuss the effects of grazing management on decomposition process. The results showed that:(1) there was a significant higher final litter mass remaining rate (R_m) in L. potaninii than in L. secalinus and mixture from 250-mesh litterbags in grazing grasslands, whereas there were no significant differences in R_m of plant litter either from 30-mesh litterbags in grazing grasslands, or from both size-mesh treatments in enclosure grasslands. (2) In 250-mesh litterbags, the k was significantly higher in the mixture than in L. potaninii in both grasslands under grazing and enclosure managements, with the intermediate values in L. secalinus litter (P<0.05). But the k of L. potaninii was significantly higher in enclosure than in grazing grasslands (P<0.05). In 30-mesh litterbags, the litter decay constant (k) was significantly higher in L. secalinus and mixture than in L. potaninii in both grasslands under grazing and enclosure managements; the k of L. potaninii litter was significantly higher in enclosure than in grazing grasslands (P<0.05). (3) In grazing grassland, the R_m of L. potaninii was significantly higher in 250-mesh than 30-mesh (P<0.05), while k was significantly higher in 30-mesh than in 250-mesh. There were significantly lower values in the mixture than in L. potaninii, with the intermediate values in L. secalinus (P<0.05). In enclosure grassland, the k of L. potaninii was significantly higher in 30-mesh than 250-mesh (P<0.05), while the contribution rate of litter arthropods to litter decomposition was significant higher in the mixture and L. potaninii than in L. secalinus. The contribution rate of litter arthropods to mixture litter decomposition was significantly higher in enclosure than in grazing grasslands (P<0.05). (4) The R_m indicated a positive correlation with litter lignin/N and litter C/P, but it indicated a negatively correlation with litter initial N and P content. And the k indicated a positive correlation with litter initial N and P, while it indicated a negatively correlation with litter lignin, N/P, C/P and lignin/P. It was suggested that plant species composition presented a significant effect on the litter final mass remaining and decay constant. The effect of grazing management on litter arthropod distribution between different mesh-size litterbags induced the decomposition differences between various species of plant litter. In conclusion, the enclosure management was conducive to promoting the contribution of litter arthropods to low-quality litter (i.e., L. potaninii) decomposition in semi-arid grasslands.

A Review of Forest Management Effects on Terrestrial Leaf Litter Inhabiting Arthropods

Leaf litter arthropods are some of the most abundant and diverse communities in forests and provide myriad ecosystem services from decomposition and mineralization to pollination and predation. They are important to forest health and management and, in turn, are affected by how we manage our forests. Various forest management techniques such as clear cutting, burning, and chemical control of invasive species all have differing effects on ground dwelling arthropods and, despite their importance, a review of the literature on these effects does not currently exist. My objective with this paper is to review the effects of different types of forest management on arthropods in leaf litter systems.

Linking plant and animal functional diversity with an experimental community restoration in a Hawaiian lowland wet forest

Testing how plant restoration influences animal taxonomic and functional diversity can shift restoration projects beyond mainly plant community considerations. We incorporated multi-trophic interactions into restoration by describing an ongoing functional trait-based restoration experiment in Hawaiian lowland tropical wet forest (Liko Nā Pilina Experiment), where litter arthropods are examined from a functional perspective thereby linking plants and higher trophic levels. We hypothesized that (1) communities with greater plant functional trait diversity would have cascading effects through food webs, increasing animal diversity and network complexity, and (2) increases in animal species and network complexity would be stronger for restoration efforts in plant communities with more complementary functional traits than those with more redundant traits. We examined experimental treatments of planted communities with the same species richness but with different plant functional trait profiles based on (1) rates of expected carbon turnover (slow or moderate), and (2) the similarity of their functional trait measurements (redundant or complementary), as determined by functional dispersion calculations. Initial data on arthropod communities and leaf litter decomposition rates revealed linkages between plant functional traits and arthropod community diversity. Overall, we argue that a more comprehensive evaluation of restoration accounts for both functional diversity and the multi-trophic nature of animal and plant communities. Developing restoration projects based on plant functional traits that influence both plant and invertebrate species provides a new paradigm, and the incorporation of both native and non-native (but non-invasive) plants shows promise in restoring ecosystem function in disturbed lowland tropical forests.