loading page

ROADS AS CONDUITS OF LAND DEGRADATION IN CAATINGA VEGETATION
  • +1
  • Nayara Mota,
  • Markus Gastauer,
  • Juan Carrión,
  • J Meira
Nayara Mota
Universidade Federal de Viçosa
Author Profile
Markus Gastauer
Instituto Tecnologico Vale
Author Profile
Juan Carrión
Universidade Federal de Viçosa
Author Profile
J Meira
Universidade Federal de Viçosa
Author Profile

Abstract

Road networks cause land degradation by mean of disturbances that can alter the biodiversity and the functioning of the Caatinga ecosystems. We tested the hypotheses that (i) Caatinga vegetation near roads is less taxonomically, functionally and phylogenetically diverse, (ii) phylogenetically and functionally more clustered than vegetation further from roads, (iii) plant traits associated with herbivory deterrence are conserved within the phylogenetic lineages, and (iv) Caatinga vegetation near roads selects for disturbance-related traits. We sampled herbaceous and woody component of vegetation in four plots near roads and four plots further from roads to test these hypotheses. Sampled species were classified according to their resprouting capacity, nitrogen fixation, succulence/spines, urticancy/toxicity, lifeform, endozoochory, maximum height and maximum diameter, before we calculated the taxonomic, functional and phylogenetic diversity of plant communities. Species richness, taxonomic, functional and phylogenetic diversities were lower in plots close to the roads, confirming roads as sources of disturbances. The phylogenetic structure of the Caatinga vegetation near roads was clustered, indicating environmental filtering by herbivory as the main pervasive disturbance in Caatinga ecosystems, since traits related to herbivory deterrence were conserved within phylogenetic lineages and were filtered in near roads. Thus, roads should be considered conduits of land degradation causing taxonomic, phylogenetic and functional impoverishment of Caatinga vegetation.