As the most abundant animals on earth, nematodes are a dominant component of the soil community. They play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil samples from all continents and biomes. For geospatial mapping purposes these samples are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into the spatial distribution patterns of soil nematode abundance and community composition, and the environmental drivers shaping these patterns.
Despite enormous diversity, abundance and their role in ecosystem processes, little is known about how community structures of soil-inhabiting nematodes differ across elevation gradient. For this, soil nematode communities were investigated along an elevation gradient of 1000–2500 masl across a temperate vegetation in Banihal-Pass of Pir-Panjal mountain range. We aimed to determine how the elevation gradient affect the nematode community structure, diversity and contribution to belowground carbon assimilation in the form of metabolic footprint. Our results showed that total nematode abundance and the abundance of different trophic groups (fungivores, herbivores and omnivores) declined with the increase of elevation. Shannon index, generic richness and evenness index indicated that nematode communities were more diverse at lower elevations and declined significantly with increase in elevation. Nematode community showed a pattern of decline in overall metabolic footprint with the increase of elevation. Nematode abundance and diversity proved to be more sensitive to elevation induced changes as more abundant and diverse nematode assemblage are supported at lower elevations. Overall it appears nematode abundance, diversity and contribution to belowground carbon cycling is stronger at lower elevations and gradually keep declining towards higher elevations under temperate vegetation cover in Banihal-pass of Pir-Panjal mountain range.
Functional diversity and detritus soil food web of soil inhabiting nematodes in natural woodland dominated by Acacia nilotica L. was studied. Functional diversity was studied in terms of trophic groups assessed by Trophic diversity index (TDI) and Shannon-Weaver index (H′), while food web was diagnosed by channel index (CI). The plant parasitic channel was determined by plant parasitic index (PPI). The stability of the soil ecosystem was measured in terms of maturity index (MI), structure index (SI) and enrichment index (EI). Shannon-Weaver index of the area was recorded as 2.1 ± 0.3 while trophic diversity index 2.6 ± 0.7, maturity index (MI) 3.1 ± 0.2, channel index 62.4 ± 28.1 and structure and enrichment indices 68.1 ± 18.5 and 15.4 ± 13.7 respectively. A high degree of positive correlation was recorded between population of dorylaims and MI while some degree of negative correlation existed between population of plant parasitic nematodes and MI. Population of other nematodes showed a positive correlation with SI and EI. The faunal profile was found to be tilted towards quadrat C giving the idea of relatively undisturbed ecosystem with moderate enrichment and fungal decomposition channel.