Abstract


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 <h1>Abstract</h1>
 Major objectives of the study was (1) to study the diversity of the major soil macrofauna (ant, earthworm and termite) in selected agroecosystems and natural forests, (2) to analyze the distribution pattern of soil fauna in relation to landuse systems and (3) to evaluate the impact of edaphic and climatic conditions of the habitat on the diversity and abundance of soil fauna.
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Detailed study was conducted in a micro-watershed of Chaliyar River (Karakkode micro-watershed-between 11015’N and 110 27’N; 76017’E and 76024’E) in the Kerala part of NBR. In total, 15 landuse practices under four main ecosystems-agricultural, agroforestry, plantations and forest ecosystems were sampled. The agricultural systems consisted of mainly annual crop fields (PA). Agroforestry practices consisted of multi-strata homegardens (HG), polyculture farms (OG), arecanut with annuals (AV), arecanut with perennials (AM) and coconut with perennials (CM). Plantations consisted of monoculture stands of arecanut (AR), coconut (CO), rubber (RU), cashew (CA), teak plantations managed by the Forest Department (TE-KFD) and teak plantations managed by private land owners (TE). The forest ecosystem consisted of degraded forest (DF) moist deciduous forest (MDF) and semi-evergreen forests (SEF).
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Altogether, 17 parataxonomic units were recorded in the study. This includes earthworms (Annelida), termites (Isoptera), ants (Hymenoptera), adult beetles and larvae (Coleoptera), earwigs (Dermaptera), Orthoptera (hoppers, crickets, mole crickets), Hemiptera (bugs, coccides, cicadas etc.), woodlice (Isopoda), centipedes (Chilopods), millipedes (Diplopods), Diptera larvae, Decapods, Mollusca, Blattids, Thysanura and spiders (Arachnida). The overall result indicted that habitat heterogeneity and landscape structure greatly influenced the spatial distribution of soil fauna. A total of 27 species of ants, seven species of earthworms and six species of termites were collected. Although, agroforests and plantations had slightly higher number of taxa than annual crop fields, the difference between these ecosystems were not significant. The lowest number of taxa was recorded in coconut monoculture (CO) plantations, while the highest was in moist-deciduous (MDF) and semi-evergreen forests (SEF), respectively. The overall variation was clearly represented in cluster and principal component analyses. 
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It is shown that diversity and abundance of soil macrofauna increased with increasing habitat heterogeneity and resource availability and decreasing disturbance. The present study proves the hypothesis that anthropogenic disturbance has negative impacts on soil fauna. Native vegetation clearance, habitat loss and fragmentation negatively affected soil macrofauna. Maintenance of adequate organic matter, wood remnants, mulching etc., facilitate micro-habitats for a vast array of soil organisms. This can be employed as good strategy for ecosystem recovery, improving soil fertility and ecosystem functions. Moreover, for rapid biodiversity inventory, higher taxonomic orders or species surrogacy is generally considered as a good tool, substantially reducing the time and cost factors. The same technique was espoused here, the grouping was good enough to characterize the spatial pattern of soil macro fauna to land intensification gradient.
<hr size="1" color="green">Dr Mujeeb Rehman works as a Research Associate in KFRI
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