How do the assemblages of epigeal Araneae and Coleoptera respond to changes in habitat structure caused by sugar cane crops in Northern Argentina?

MACAGNO, H.B., A.X.GONZALEZ REYES, J.A. CORRONCA, S.M. RODRÍGUEZ-ARTIGAS, & G.E. FLORES

Neotropical Biodiversity

Taylor & Francis

Lugar: Londres; Año: 2022 vol. 8 p. 323 - 342

In Northwest Argentina, nothing is known about the relationship of Araneae and Coleopterawith sugar cane crops. Using pitfall traps in three continuous native forest sites (N) and threenative forest windbreaks surrounded by sugar cane crops (W) in the province of Salta, weassessed a)- whether the native diversity of epigeal Araneae and Coleoptera in the ChacoSerrano forest changes as a result of the fragmentation of the habitat caused by the sugar caneplots, and b)- whether the diversity of predatory species increases in native forest windbreaksas a consequence of the contribution of species that come from crops. In the spring of 2006and the summer of 2007, we collected 599 Araneae and 555 Coleoptera, with communityW (S = 132, N = 535) containing much more species but fewer individuals than communityN (S = 111, N = 619). We found that the spatial and phenological patterns of the alpha and betadiversities of N were altered in W communities. Thus, habitat fragmentation generated bysugar cane plots led to the local extinction of native Araneae and Coleoptera species. Theabundance of generalist Araneae and herbivorous Coleoptera increased in W habitats, but thecoprophagous and detritivorous beetles decreased. The diversity of predatory species (Araneaeand some Coleoptera) increased in W habitats, although their abundance declined relative toN habitats. Species turnover determined beta diversity between N and W sites; however,between the W sites, nestedness increased and spiders showed a greater loss of species. Thespatial heterogeneity between sites, seasons, and habitats had a substantial effect on thecomposition of the Araneae and Coleoptera assemblages, hence influencing regional diversity.Eight species were habitat indicators, particularly Leprolochus birabeni (Zodariidae), whichresponds unfavourably to perturbations in the agricultural landscape, and could be deployedas environmental monitors in the Chaco Serrano.