Density and diversity of macroinvertebrates in Colombian Andean streams impacted by mining, agriculture and cattle production

PeerJ

article

Ana M. Meza-Salazar¹  Giovany Guevara³  Lucimar Gomes-Dias¹  Carlos A. Cultid-Medina⁴ 

[1] Facultad de Ciencias Exactas y Naturales, Grupo de Investigación BIONAT, Universidad de Caldas;Department of Applied Ecology, North Carolina State University, College of Agriculture and Life Sciences;Facultad de Ciencias, Departamento de Biología, Grupo de Investigación en Zoología ,(GIZ), Universidad del Tolima;Red de Diversidad Biológica del Occidente Mexicano, Instituto de Ecología;CONACYT

关键词: Aquatic insects;    Hill series;    Biomonitoring;    Rank-density curve;    Neotropical region;   

DOI  :  10.7717/peerj.9619

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundMining, agriculture and cattle production are activities that threaten the quality and quantity of water resources in the Colombian Andes. However, many drainage basins in this region have not been subjected to simultaneous evaluation of the impact these activities have on the density, diversity and composition of aquatic macroinvertebrates (AMI). The first two of these ecological variables are expected to decrease drastically from zones with no apparent impact towards areas with anthropogenic activity, which areas with mining will present the most impoverished AMI community.MethodsWe evaluated the density, diversity and composition dissimilarity of AMI in streams impacted by gold mining, agriculture and cattle production. Two reference streams were also studied. Six benthic samplings were conducted bimonthly (Feb 2014–Feb 2015) using a Surber net. Water samples were taken in order to make environmental evaluation among the aforementioned streams, including hydrological, physicochemical and bacteriological parameters (HPCB). Diversity was evaluated as the effective number of RTUs—recognizable taxonomic units—by comparing the richness, typical diversity, and effective number of the most abundant RTUs. Compositional dissimilarity was examined with nMDS and CCA analysis.ResultsMining) was partially fulfilled, since the agriculture-dominated stream presented a more impoverished AMI community than that of the gold mining stream. However, these streams presented lower diversity than the cattle production and reference streams, and the AMI density only differed significantly between one reference stream and the agriculture stream. The AMI composition in the agriculture-dominated stream clearly differed from that of the other streams.DiscussionThe observation of a more impoverished AMI community in agricultural production areas compared to those with mining or cattle production may reflect the importance of the remaining riparian vegetation, which was scarce at the stream with agricultural activity. Moreover, the low diversity, and mainly the reduced AMI richness, in the agriculture stream coincided with the absence of insect genera are intolerant to deterioration of the biological and physicochemical conditions of the water (e.g. Anacroneuria).ConclusionsThe results suggest that the local impact of agricultural activities may be of equal or greater magnitude than that of mining in terms of AMI density, diversity and composition, in the Colombian Andean riverscape. Future studies should systematically evaluate, throughout the annual cycle, the relative effects of the productive land use, the remaining native vegetation cover and the consequent changes in the HPCB parameters of the water on AMI communities in Colombian Andean basins.

【 授权许可】

CC BY