Abundance and diversity of soil invertebrates in annual crops, agroforestry and forest ecosystems in the Nilgiri biosphere reserve of Western Ghats, India

Abstract

Biologically mediated soil processes rely on soil biota to provide vital ecosystem services in natural and managed ecosystems. However, land use changes continue to impact on assemblages of soil biota and the ecosystem services they provide. The objective of the present study was to assess the effect of land use intensification on the distribution and abundance of soil invertebrate communities in the Nilgiri, a human-dominated biosphere reserve of international importance. Soil invertebrates were sampled in 15 land use practices ranging from simple and intensively managed annual crop fields and monoculture tree plantations through less intensively managed agroforestry and pristine forest ecosystems. The lowest taxonomic richness was found in annual crops and coconut monoculture plantations, while the highest was in moist-deciduous and semi-evergreen forests. With 21 ant species, agroforestry systems had the highest diversity of ants followed by forest ecosystems (12 species). Earthworms and millipedes were significantly more abundant in agroforestry systems, plantations and forest ecosystems than in annual crop fields. Ants, termites, beetles, centipedes, crickets and spiders were more abundant in forest ecosystems than in other ecosystems. It is concluded that annual cropping systems have lower diversity and abundance of soil invertebrates than agroforestry and natural forest ecosystems. These results and the literature from other regions highlight the potential role that agroforestry practices can play in biodiversity conservation in an era of ever-increasing land use intensification and habitat loss.

Spider diversity (Arachnida; Araneae) in different plantations of Western Ghats, Wayanad region, India

“…Land use intensification can reduce the abundance and diversity of spider species through physical removal, destruction of their microhabitats or through changing the microclimatic conditions within the habitat. Previous studies in the Western Ghats have also indicated the effects of land use changes on the diversity of soil biota (Rossi and Blanchart 2005;Rahman et al 2011;Mandle and Ticktin 2015).…”

“…Western Ghats mountain ranges of India, by far the most densely populated global biodiversity hotspot (Cinacotta et al 2000), has a mosaic of natural, semi-natural and agro-ecosystems in close proximity to one another. Human-induced changes in land use are globally ubiquitous and specifically of high importance in the Western Ghats (Rahman et al 2011). With an increase in anthropogenically dominated habitats, previously abundant natural habitats have become smaller and more fragmented (Kumara et al 2004;Chakraborty et al 2019).…”

Tropical forest conversion to rubber plantation affects soil micro- & mesofaunal community & diversity

“…Pesticides are generally used on rubber plantations, for example, to kill weeds, and are a possible factor producing the observed differences in soil metazoan diversity, as they are toxic to non-target species including soil animals 83,84 . A prevalent management practice in rubber plantations is repeated application of glyphosate, (alone or in a mixture with other pesticides) 31 which increases the presence of glyphosate residues in soils 85–88 and can be detected in top soils even after two years since the last spraying 86 .…”

Sustainable Soil Management for Food Security in South Asia

“…Accelerated soil erosion, along with crop intensification, not only affects soil fertility but also the below-and aboveground biodiversity, including crop genetic diversity and wild diversity which finally reduces the SOM content (Hobbs et al 2008;Pimentel and Burgess 2013). Land use changes cause significant alterations in soil fauna and flora (Rossi and Blanchart 2005;Rahman et al 2012) which are affecting long-term biodiversity in SA.…”