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1.
Soil nematode communities can provide important information about soil food web structure and function. However, how soil nematode communities and their metabolic footprints change over time in temperate forests is not well known. We examined the changes in the composition, diversity and metabolic footprints of soil nematode communities in three differently-aged (young, mid and old) forests of the Changbai Mountains, China. Carbon flows through different nematode trophic groups were also quantified based on nematode biomasses. The results showed that the highest abundance and diversity of total nematodes was found in the mid forest. Nematode communities were characterized by the replenishment in abundance but not the replacement of dominant genera. A low enrichment footprint in the young forest suggests a decline in available prey, while a high enrichment footprint in the mid forest indicates an increase in resource entry into soil food web. The relationship between the carbon flows of omnivores-predators and fungivores was stronger than that among other trophic groups. Our study shows that bottom-up effects of the vegetation, the soil environment and the connectedness of nematode trophic groups are all important driving forces for nematode community structure in temperate forests. 相似文献
2.
Changes taking place in the communities of soil nematodes of an artificially sown meadow under the impact of annually applied mineral fertilizers have been studied in a field experiment for nine years. It is shown that changes in the species composition, trophic structure, and numbers of nematodes from different genera depend on the fertilizer applied and on the competitiveness of the plant species grown. The spectra of nematode genera sensitive to the complete mineral fertilizer (NPK) and to the particular nutrients have been identified with the use of a number of parameters, including the maturity index of nematode communities, the biotope preferences of the particular nematode genera, and the general pattern of nematode habitats. The results obtained in this study can be used to assess the effect of mineral fertilizers on the soil fauna and to suggest optimum application rates of mineral fertilizers ensuring the sustainable development of meadow herbs. The use of the data on the trophic structure of nematode communities for predicting the ways of organic matter decomposition in the soil is discussed. 相似文献
3.
《Applied soil ecology》2007,35(1):203-212
Biological soil crusts are key mediators of carbon and nitrogen inputs for arid land soils and often represent a dominant portion of the soil surface cover in arid lands. Free-living soil nematode communities reflect their environment and have been used as biological indicators of soil condition. In this study, we test the hypothesis that nematode communities are successionally more mature beneath well-developed, late-successional stage crusts than immature, early-successional stage crusts. We identified and enumerated nematodes by genus from beneath early- and late-stage crusts from both the Colorado Plateau, Utah (cool, winter rain desert) and Chihuahuan Desert, New Mexico (hot, summer rain desert) at 0–10 and 10–30 cm depths. As hypothesized, nematode abundance, richness, diversity, and successional maturity were greater beneath well-developed crusts than immature crusts. The mechanism of this aboveground–belowground link between biological soil crusts and nematode community composition is likely the increased food, habitat, nutrient inputs, moisture retention, and/or environmental stability provided by late-successional crusts. Canonical correspondence analysis of nematode genera demonstrated that nematode community composition differed greatly between geographic locations that contrast in temperature, precipitation, and soil texture. We found unique assemblages of genera among combinations of location and crust type that reveal a gap in scientific knowledge regarding empirically derived characterization of dominant nematode genera in deserts soils and their functional role in a crust-associated food web. 相似文献
4.
在2013年对大连市大魏家镇海水入侵污染区域进行了土壤理化性质和线虫群落调查,在此基础上,应用线虫多样性指数和功能类群指数研究海水入侵土壤盐渍化以及不同土地利用方式对土壤线虫群落结构的影响。研究期间共鉴定出土壤线虫30科48个属。其中食细菌类群的比例最高,共17属,占总数42.81%;其次为杂食/捕食类群,共9个属,占总数25.26%。优势属为Plectus。结果显示:海水入侵已造成该地区土壤盐渍化;土壤盐分与线虫生态指数SR、f/b、NCR、PPI、MI、PPI/MI、PP%、FF%、BF%和OP%存在显著的相关关系;土地利用方式、土壤盐分对线虫群落的生态指数影响显著,是影响该地区土壤线虫群落结构的主要因素。通过开展土壤线虫对海水入侵土壤盐渍化响应的研究,为促进沿海受海水污染区土壤生态系统的健康发展提供科学依据。 相似文献
5.
Analysis of nematode communities is a potential biological proxy to monitor soil health. Traditionally, nematodes are extracted from 200 g of soil and then identified based on morphology. However, the optimal soil sample size to accurately characterise nematode communities using molecular methods is unknown. Using a combined relative real-time PCR and T-RFLP approach we analysed nematode communities extracted from triplicate samples ranging from 1 to 200 g soil. Our data indicated that for molecular based analyses, soil sample sizes <200 g of soil do not accurately represent the abundance of nematodes and <100 g samples are less likely to reflect the true community composition. Thus characterisation of nematode communities from low sample sizes may not be robust. 相似文献
6.
《Applied soil ecology》2007,35(2):329-339
We evaluated the response of riparian forest soil nematode community structure to the physico-chemical environment associated with urban land use. Soils were sampled seasonally between December 2000 and October 2002 along an urban—rural transect in Asheville, North Carolina. We characterized the taxonomic (to genus) and functional composition (trophic groups) of the nematode community of forest soils, as well as several nematode ecological indicators (maturity index, channel index, weighted faunal index). The diversity of nematode genera was not affected by urban land use. However, there tended to be functional differences in the nematode communities along the land use gradient. The urban soils tended to have lower abundances of predatory and omnivorous nematodes. Differences in channel index scores indicated that there was less fungal dominance in the soil food webs of the urban soils. Our results indicate that the functional composition of the soil food web is an important component of soil biodiversity that can be affected by land use practices. This study was conducted in a relatively small city; hence the influence of pollutants on the soil environment was not as great as in larger cities. Correspondingly, the impact on the soil nematode community was not very severe. The utilization of the nematode community assemblage as an indicator of soil conditions should be further explored in urban places of differing magnitudes of environmental effects. 相似文献
7.
放牧管理对青藏高原东缘高寒草甸土壤线虫的影响及作用机制 总被引：2，自引：0，他引：2
不同强度、季节的放牧是草地生态系统中主要的放牧管理措施,在生物多样性维持以及生态过程发挥中起着重要的作用,然而,关于青藏高原东缘高寒草甸地区放牧对土壤线虫群落的研究甚少。本文调查了放牧（轻度、中度和重度）对植物群落、土壤理化性质和线虫群落的影响。结果表明：植物群落、土壤理化性质和线虫群落受到放牧、时间以及放牧和时间共同作用的影响;食细菌线虫、植物凋落物生物量、根生物量、土壤含水量、土壤有机碳含量在轻度放牧草地内最高（p＜0.05）;杂类草生物量在中度放牧草地内最高;杂食线虫数量在重度放牧地内最低（p＜0.05）。植物群落和土壤特性与土壤线虫群落有明显的相关关系（p＜0.05）。结构方程模型显示食草动物主要通过植物群落影响植食和食细菌线虫,进一步的研究应针对植物群落多样性以及个体特征对线虫群落的影响。 相似文献
8.
为研究施用过量的农用化学品对土壤线虫群落组成及多样性的影响,采用定点试验的方法,在哈尔滨市呼兰区选择典型农田生态系统进行试验,对比研究土壤线虫群落对施用过量的氮肥、磷肥、钾肥、除草剂及杀虫剂的响应。在试验田中共鉴定出土壤线虫27科45属,其中Cephalobus和Aphelenchus为优势属。施用不同浓度的各类农用化学品对土壤线虫群落组成、多样性均产生一定影响。线虫总数及食细菌线虫、食真菌线虫、植物寄生线虫数量在不同处理间均存在显著差异(P<0.05);其中,植物寄生线虫的相对丰度随化肥施用量的升高呈增加趋势。从土壤线虫的生态指数来看,除PPI(植物寄生线虫成熟指数)外,其他生态指数[MI(成熟度指数)、F/B(食真菌线虫与食细菌线虫数量比值)、Evenness(均匀度指数)、SR(丰富度指数)、H’(多样性指数)]在施用不同农用化学品处理之间也存在显著差异,并且,MI随着施用钾肥、氮肥浓度的增加而降低。土壤线虫可以作为揭示施用农用化学品过程中土壤质量变化的生物学指标,其群落及多样性的变化表明土壤线虫群落对农用化学品的过量施用产生了响应,过量施用农用化学品会增加土壤生态系统的干扰,对土壤环境造成威胁。 相似文献
9.
Conversion of arable land into semi-natural grassland or heath land is a common practice for restoring and conserving plant diversity. However, little is known about the effectiveness of land conversion for restoring and conserving taxonomic and functional diversity in the soil. We studied soil nematode community development in a chronosequence of abandoned fields and related this to plant community development. The taxonomic and functional composition of the soil nematode community was analyzed to detect changes in soil food web structure, using semi-natural sites and theoretical plant and soil communities as references.While plant communities clearly developed towards the semi-natural references, there was less direction in succession of nematode taxa. The number of fungal feeding nematodes increased after land abandonment. Numbers of omni-carnivorous nematodes expanded only during the first years, after which there were no substantial changes for the next three decades. Plant communities on the ex-arable fields developed towards the theoretical reference plant associations Galio hercynici-Festucetum ovinae and Genisto anglicae-Callunetum. Nematode communities developed away from a theoretical community indicative of arable land, but there was no clear development towards a theoretical (semi-)natural reference. Our results show that restoration and conservation of plant communities is of limited indicative value for developments belowground: successful restoration of plant diversity does not necessarily imply successful restoration of belowground diversity. Assessing the impact of conservation measures on restoring soil biodiversity requires information on belowground community composition of (semi-)natural areas in order to establish proper references for restoration sites. 相似文献
10.
Woody plant encroachment is an important land cover change in dryland ecosystems throughout the world, and frequently alters above and belowground primary productivity, hydrology, and soil microbial biomass and activity. However, there is little known regarding the impact of this geographically widespread vegetation change on the biodiversity and trophic structure of soil fauna. Nematodes represent a major component of the soil microfauna whose community composition and trophic structure could be strongly influenced by the changes in ecosystem structure and function that accompany woody encroachment. Our purpose was to characterize nematode community composition and trophic structure along a grassland to woodland chronosequence in the Rio Grande Plains of southern Texas. Research was conducted at the La Copita Research Area where woody encroachment has been documented previously. Soil cores (0–10 cm) were collected in fall 2006 and spring 2007 from remnant grasslands and woody plant stands ranging in age from 15 to 86 years, and nematodes were extracted by sugar centrifugation. Neither nematode densities (3200–13,800 individuals kg−1 soil) nor family richness (15–19 families 100 g−1 soil) were altered by woody encroachment. However, family evenness decreased dramatically in woody stands >30 years old. This change in evenness corresponded to modifications in the trophic structure of nematode communities following grassland to woodland conversion. Although root biomass was 2–5× greater in wooded areas, root-parasitic nematodes decreased from 40% of all nematodes in grasslands to <10% in the older wooded areas, suggesting the quality (C:N or biochemical defenses) of woody plant root tissue could be limiting root-parasites. In contrast, bacterivores increased from 30% of nematodes in grasslands to 70–80% in older woody patches. This large increase in bacterivores may be a response to the 1.5–2.5× increase in soil microbial biomass (bacteria + fungi) following woody encroachment. Therefore, while energy flow through grassland nematode communities appears to be distributed nearly equally among herbivory, fungivory and bacterivory, the energy flow through nematode communities in wooded areas appears to be based primarily on bacterivory. We speculate that these shifts in nematode community composition and trophic structure could have important implications for ecosystem patterns and processes. First, the low abundance of root-parasitic nematodes (and presumably root herbivory) under woody plants may be one mechanism by which woody plants are able to establish and compete effectively with grasses during succession from grassland to woodland. Second, the large increase in bacterivores following woody encroachment likely accelerates microbial turnover and the mineralization of N, thereby providing a feedback that enables the persistence of N-rich woody plant communities. 相似文献
11.
The carrying capacity for microflora and nematofauna was manipulated (using a bactericide, a fungicide, manure or a growing millet plant) in a poor tropical soil, in order to identify relationships between the soil microbes and nematodes and to assess the influences of these organisms on nitrogen flux. The experiment was conducted for 4 months in containers under greenhouse conditions, with analyses of soil, nematofauna and microbial characteristics at regular intervals. Manure input and initial bactericide application led to a significant increase in bacterial-feeding and fungal-feeding nematodes of coloniser-persister classes 1 and 2, respectively, whereas high manure input stimulated omnivorous nematodes (i.e. Microdorylaimus rapsus) which became the dominant trophic group. Changes in abundance of the different bacterial-feeding nematode taxa between treatments seemed to be more related to changes in the structure of the microbial communities than to the total amount of micro-organisms, as suggested by the RISA fingerprint analysis of the bacterial communities. Canonical analysis of nematode feeding guilds, combined with soil microbial and mineral nitrogen parameters as well as multiple regression showed that the bacterial-feeding nematodes influenced the inorganic N content in the soil whereas microbial biomass was determined by total nematode abundance and not by any specific trophic group. 相似文献
12.
Human activities are causing climatic changes and alter the composition and biodiversity of ecosystems. Climate change has been and will be increasing the frequency and severity of extreme climate events and natural disasters like floods in many ecosystems. Therefore, it is important to investigate the effects of disturbances on ecosystems and identify potential stabilizing features of ecological communities. In this study, soil microbial and nematode communities were investigated in a grassland biodiversity experiment after a natural flood to investigate if plant diversity is able to attenuate or reinforce the magnitude of effects of the disturbance on soil food webs. In addition to community analyses of soil microorganisms and nematodes, the stability indices proportional resilience, proportional recovery, and proportional resistance were calculated. Generally, soil microbial biomass decreased significantly due to the flood with the strongest reduction in gram-negative bacteria, while gram-positive bacteria were less affected by flooding. Fungal biomass increased significantly three months after the flood compared to few days before the flood, reflecting elevated availability of dead plant biomass in response to the flood. Similar to the soil microbial community, nematode community structure changed considerably due to the flood by favoring colonizers (in the broadest sense r-strategists; c–p 1, 2 nematodes), particularly so at high plant diversity. None of the soil microbial community stability indices and few of the nematode stability indices were significantly affected by plant diversity, indicating limited potential of plant diversity to buffer soil food webs against flooding disturbance. However, plant diversity destabilized colonizer populations, while persister populations (in the broadest sense K-strategists; c–p 4 nematodes) were stabilized, suggesting that plant diversity can stabilize and destabilize populations depending on the ecology of the focal taxa. The present study shows that changes in plant diversity and subsequent alterations in resource availability may significantly modify the compositional shifts of soil food webs in response to disturbances. 相似文献
13.
《Applied soil ecology》2000,14(1):27-36
The nematode communities of 36 grassland ecosystems in Romania, belonging to different plant associations and soil types, were studied. The abundance of nematodes, the species and trophic types present, as well as their distribution in relation to plant community and soil characteristics are analyzed and discussed.The abundance of nematodes from the 36 grasslands studied ranged between 0.41 × 106 and 8.57 × 106 individuals/m2, and a total of 121 genera and 145 species of nematodes were found. The highest diversity was found in grasslands developed on brown earth soil (65–67 genera and 74–76 species), with least diversity in those evolving on podzol and lithosol (33–36 genera with 25–28 identified species). Most of the dominant taxa were found in specific soil layers; some obligate plant parasitic genera (e.g., Paratylenchus, Rotylenchus, Criconema) showed preference for deeper soil layers. The nematode diversity index (H′), with values ranging between 2.38 and 3.47, did not differ significantly between the different types of grasslands. Plant feeding, bacterial feeding, hyphal feeding and omnivorous nematodes were the main groups in mountainous grasslands developed on different soil types. Plant feeding and bacterial feeding nematodes dominated the trophic structure and more plant feeders (62–69%) were found in communities of subalpine and alpine grasslands developed on podzol and alpine meadow soil, than in those developed on rendzina and lithosol (27–33%). The ratio of hyphal feeding to bacterial feeding nematodes (Hf/Bf) is constantly in favour of the bacterial feeding group, the values being an indicator of good soil fertility for most studied grasslands. The nematode communities of grasslands are grouped into six main clusters according to their genera affinity and distinguished by different grassland and soil types. Communities from subalpine grasslands developed on rendzina, acid brown and lithosol have the greatest similarities. An ordination of nematode communities in relation to important environmental variables is presented. Environmental variables relevant in explaining the patterns of nematode composition in grasslands, using canonical correspondence analysis (CCA), are: humus, pH, total nitrogen, exchangeable bases and soil type. No single factor could be selected. 相似文献
14.
地中海农业生态系统中土壤自生线虫种群多样性及动态研究 总被引：5，自引：2，他引：5
To determine the effect of agricultural management on the dynamics and functional diversity of soil nematode communities in a carrot field at Kibbutz Ramat Hakovesh, Israel, soil samples from 0--10 cm and 10--20 cm depths were collected during the growing season of carrot. Indices were used to compare and assess the response of soil free-living nematode communities to agricultural management. Eighteen nematode families and 20 genera were observed during the growing period, with Cephalobus, Rhabditidae, Aphelenchus, Tylenchus, and Dorylaimus being the dominant genera/families. During the planting, mid-season and post-harvest periods the total number of nematodes at both depths was significantly lower (P < 0.01) in the carrot treatment than in the control plots, while during the harvest period at both depths total nematodes and bacterivores were significantly higher in the treatment plots (P < 0.01). The values of the maturity index (MI) at both depths were found to be significantly lower in the treatment plots than in the control plots during the pre-planting period (P < 0.05). Overall, WI, MI and PPI were found to be more sensitive indicators than other ecological indices for assessing the response of nematode communities to agricultural management in a Mediterranean agroecosystem. 相似文献
15.
Climate change is predicted to increase the frequency of freeze-thaw events in Arctic, sub-Arctic, Boreal, and some temperate regions. The aim of this study was to examine the effects of freeze-thaw events on abundance and composition of the soil community, thereby clarifying whether freeze-thaw events act as a distributing factor on microbes and nematodes. We investigated comparable soils from sites with and without seasonal freezing to determine whether the communities in these soils responded differently to freeze-thaw events and whether freeze tolerance of nematodes is adaptive. In a microcosm experiment we assessed microbe and nematode abundances and nematode community composition. Continuous freezing had a greater effect on both abundance and community composition of soil organisms than successive freeze-thaw cycles. In addition, freezing had clearer effects on the nematode community than on microbial biomass. The previous freezing history of the sampling sites played a role in the changes of the nematode community under freezing exposure. In the soil that had never been exposed to freezing, freezing particularly inhibited members of the nematode community that usually colonize patches of high microbial activity very rapidly and limited their ability to fill their niche as extreme colonizers. This may play a role for the ability of non-freezing adapted nematode communities to spread northwards with climate change. 相似文献
16.
南方地区冷浸田土壤线虫的分布特征 总被引：1，自引：0，他引：1
为了解南方地区冷浸田土壤线虫分布状况,2011—2012年期间,对湖北、安徽、江西、湖南、福建、浙江、广东和贵州8个省份的冷浸田进行土壤线虫调查。结果表明:在所有省份中,共鉴定出2纲8目24科55属,其中潜根属(Hirschmanniella)和丝尾垫刃属(Filenchus)为优势属,两者占线虫总数的46.36%,丝尾垫刃属、潜根属、头叶属(Cephalobus)、滑刃属(Aphelenchoides)在我国南方8省份的冷浸田均有分布。冷浸田线虫密度为非冷浸田的48.04%,冷浸田线虫密度范围为72~735条/100 g干土。冷浸田土壤线虫数量分布主要受土壤含水量和电导率因素影响,潜根属与含水量显著正相关,与电导率显著负相关。 相似文献
17.
科尔沁沙地黑沙蒿人工植被土壤线虫群落特征 总被引：1，自引：0，他引：1
本文针对科尔沁沙地黑沙蒿人工植被土壤线虫的总数、群落组成、营养类群进行了研究。结果表明,随着黑沙蒿种植年限的增加,土壤线虫数量显著增加。不同年限黑沙蒿植被之间土壤线虫总数差异显著(P<0.01)。在本研究中共获得线虫13科19属,其中Acrobeles为优势属。在半流动沙丘生态系统中,植物寄生线虫为优势营养类群;而在黑沙蒿人工植被生态系统中,线虫群落逐渐向以食细菌线虫占优势的方向演替。本实验结果表明,土壤线虫群落结构对退化沙漠生态系统的恢复阶段具有很好的生物指示作用。 相似文献
18.
长期施用有机肥对红壤旱地土壤线虫群落的影响 总被引：8，自引：0，他引：8
基于红壤旱地(玉米)的长期施肥试验,研究长期施用有机肥对土壤线虫分布特征及群落结构的影响。田间试验处理包括:CK(对照)、ON1(低量有机肥)、ON2(高量有机肥)和ON2L(高量改良有机肥)。结果表明,施肥8a后,红壤旱地中共鉴定出15科、29属土壤线虫,包括8属植物寄生线虫、9属食细菌线虫、3属食真菌性线虫和9属捕食杂食性线虫,短体属(Pratylenchus)、小杆属(Rhabditis)和原杆属(Pro-torhabditis)为优势属。不同施肥处理中,土壤线虫总数的大小顺序为ON2>ON1>ON2L>CK。线虫群落生态指数对于施用有机肥有不同的响应:除SI外,其他虫群落生态指数均有显著差异,通过线虫群落结构的变化很好地反映了土壤的肥力变化状况,土壤线虫可以作为施有机肥过程中指示土壤健康质量的一个重要的生物学指标。 相似文献
19.
It is increasingly believed that substantial soil organic carbon (SOC) can be sequestered in conservation tillage system by manipulating the functional groups of soil biota. Soil aggregates of different size provide diverse microhabitats for soil biota and consequently influence C sequestration. Our objective was to evaluate the contributions of soil biota induced by tillage systems to C sequestration among different aggregate size fractions. Soil microbial and nematode communities were examined within four aggregate fractions: large macroaggregates (>2 mm), macroaggregates (2–1 mm), small macroaggregates (1–0.25 mm) and microaggregates (<0.25 mm) isolated from three tillage systems: no tillage (NT), ridge tillage (RT) and conventional tillage (CT) in Northeast China. Soil microbial and nematode communities varied across both tillage systems and aggregate fractions. The activity and abundance of microbes and nematodes were generally higher under NT and RT than under CT. Among the four aggregate fractions, soil microbial biomass and diversity were higher in microaggregates, while soil nematode abundance and diversity were higher in large macroaggregates. Structural equation modelling (SEM) revealed that the linkage between microbial and nematode communities and their contributions to soil C accumulation in >1 mm aggregate fractions were different from those in <1 mm aggregate fractions. Higher abundance of arbuscular mycorrhizal fungi (AMF) could enhance C retention within >1 mm aggregates, while more gram-positive bacteria and plant-parasitic nematodes might increase C accumulation within <1 mm aggregates. Our findings suggested that the increase in microbial biomass and nematode abundance and the alteration in their community composition at the micro-niche within aggregates could contribute to the higher C sequestration in conservation tillage systems (NT and RT). 相似文献
20.
《European Journal of Soil Biology》2008,44(2):238-246
Shifting sand dunes threatened the Baotou-Lanzhou railway being kept on operation smoothly seriously crossing Shapotou on the southeastern edge of the Tengger Desert (China). Artificial vegetation input was employed in Shapotou and a vegetated belt was established for stabilizing the shifting sand dunes. Nematode communities from bare soil between vegetation (ST, STI) and soil under the vegetation (ST-V, STI-V) in the vegetation belt, were investigated. All sites received natural rainfall, of which STI and STI-V received irrigation supplements. Total 43 genera were found in four types of soil samples, and Acrobeles, Acrobeloides, Chiloplacus, Panagrolaimus, Aphelenchoides and Ditylenchus were dominant genera in our study. Nematode abundance per 100 g fresh soil (47–552), the number of taxa identified (8–20), species richness (1.51–3.41), the proportion of plant feeders (0.3%–4.2%) and abundance of all cp groups responded to vegetation. The proportion of omnivores (0.5%–7%), the number of taxa identified, Shannon index (1.26–2.12), species richness, genus dominance (0.18–0.40) and abundance of cp3–5 responded to irrigation supplements. The application of PCA helped to reveal that almost all nematode taxa exhibited a positive loading on the horizontal axis, it implied that nematode abundance was generally higher on sites with planted input. Besides, it showed a vegetation gradient from bare soil between vegetation to soil under vegetation along the first axis, while an irrigation gradient along the second axis. Similarly, classification analysis based on all cased involved indicated that two-main group of nematodes was distinguished by their habitats under vegetation from bare soil. Those results suggested that vegetation input might play a more important role on nematode community composition than irrigation supplements for stabilization of shifting sand dunes. Therefore, nematode community composition could be as an indicator of stabilization of sand dune approaches of plant input with only natural rainfall versus with natural rainfall in combination with irrigation supplements in our system. However, the apparent anhydrobiotic state of the nematode fauna required special consideration in desert system, thus the utilization of the nematodes as an indicator of stabilization of sand dune regimes should be further explored on anhydrobiotic nematodes. 相似文献