Different land-use types equally impoverish but differentially preserve grassland species and functional traits of spider assemblages

Abstract

Land-use change is one of the major drivers of biodiversity loss by introducing environmental modifications, which excludes native species unable to adapt to the novel conditions. Grasslands are among the most threatened biomes; understanding the influence of different land-use types on native species is crucial to achieving sustainable management policies. We hypothesized that land-use types that partially conserve the original vegetation cover would show higher taxonomic and functional diversity and similarity with native assemblages than land-use types that replace the original vegetation cover. We compared the taxonomic and functional alpha and beta diversity of spider assemblages between soybean crops, eucalypt plantations, and cattle fields with seminatural grasslands. Through null models, we assessed the standardized effect sizes to test differences in the strength of environmental filtering among land-use types. Environmental changes introduced by different land-use types resulted in assemblages differentiated in species and trait composition, taxonomically and functionally impoverished with respect to seminatural grasslands. All land-use types drove species replacement and trait loss and replacement of grassland spiders. Each land-use showed a characteristic species and trait composition. Most of the grassland traits were not lost but were under or over-represented according to the land-use type. Only in soybean crops the formation of spider communities would be mainly driven by environmental filtering. Changes in land-use decreased species diversity and modified the composition of spider species and functional traits leading to differentiated spider assemblages. As spider species and traits varied among land-uses, a mitigation measure against grasslands biodiversity loss could be the development of productive landscapes with a mosaic of land-use types, as each of them would provide microhabitats for species with different requirements. Because land-use types mainly led to the rearrangement of grassland functional trait values, most of spider functions might be conserved in mosaics of land-use types.

Influencia del uso de la tierra sobre la relación entre la diversidad de arañas y sus presas potenciales

“…En este estudio, la menor diversidad funcional en forestaciones con mayor diversidad de presas en relación con las plantaciones forestales control se podría explicar por cambios en la proporción relativa de los valores o estados de los diferentes rasgos funcionales registrados en las especies que componen los ensambles de esos ambientes. Es posible que estos cambios se deban a que en las plantaciones, los rasgos funcionales de los ensambles toman valores más extremos (Stubbs and Wilson 2004;Pinto et al 2021) frente a una limitación en los recursos alimenticios; en sitios los recursos no son limitantes varias especies podrían compartir los valores para los rasgos funcionales y por lo tanto verse reducida la diversidad funcional del ensamble.…”

“…Si bien el control de abajo hacia arriba por parte de los recursos y el efecto de los usos sobre los ensambles han sido estudiados ampliamente (Horváth et al 2005;Prieto-Benítez and Méndez 2011), hasta donde sabemos, en este trabajo se analiza por primera vez la interacción entre ellos. Con respecto a la ausencia de respuesta a la interacción analizada por parte de la riqueza taxonómica, los hallazgos de este trabajo son consistentes con resultados previos (Pinto et al 2021) en los que se aportó evidencia en favor de que las condiciones ambientales impuestas por los tipos de uso determinarían la riqueza de los ₉₅₄ CM P���� �� �� Ecología Austral 32:945-956 ensambles de arañas en hábitats antropizados. Sin embargo, es posible que la ausencia de evidencia de control de abajo hacia arriba en la riqueza y la abundancia de arañas también se encuentre asociada a limitaciones del estudio, como se explicó previamente.…”

Seasonal variation in spider abundance in Muthupet mangroves, South East coast of Tamilnadu, India

“…Perpetrated in the biological control of pests in disparate ecological conditions, physiological activities of these ectotherms, such as reproduction, development, growth, moults, inter-moult periods, survival rate, and behaviour, are typically in uenced by variations in temperature (Maranhão & Marques, 2003 Yalsuyi et al, 2021). In turn, this ectothermy present in both spiders and other arthropods depends on the external environment, so alterations in environmental uctuations can modify or affect the species' physiology (Grossi & Canals, 2015;Prokić et al, 2019Prokić et al, , 2021Qyli et al, 2020;Pinto et al, 2021;Hodkovicova et al, 2022). There are 117 families with 443 genera and 48,127 arachnid species across the Globe (World Spider Catalogue, 2019).…”