Parreira de Castro Diego Marcel, Reis de Carvalho Débora, Pompeu Paulo dos Santos, Moreira Marcelo Zacharias, Nardoto Gabriela Bielefeld, Callisto Marcos
Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Biologia Geral, Laboratório de Ecologia de Bentos, Belo Horizonte, MG, Brasil.
Universidade Federal de Lavras, Departamento de Biologia, Setor de Ecologia, Laboratório de Ecologia de Peixes, Lavras, MG, Brasil.
PLoS One. 2016 Mar 2;11(3):e0150527. doi: 10.1371/journal.pone.0150527. eCollection 2016.
It is well recognized that assemblage structure of stream macroinvertebrates changes with alterations in catchment or local land use. Our objective was to understand how the trophic ecology of benthic macroinvertebrate assemblages responds to land use changes in tropical streams. We used the isotope methodology to assess how energy flow and trophic relations among macroinvertebrates were affected in environments affected by different land uses (natural cover, pasture, sugar cane plantation). Macroinvertebrates were sampled and categorized into functional feeding groups, and available trophic resources were sampled and evaluated for the isotopic composition of 13C and 15N along streams located in the Cerrado (neotropical savanna). Streams altered by pasture or sugar cane had wider and more overlapped trophic niches, which corresponded to more generalist feeding habits. In contrast, trophic groups in streams with native vegetation had narrower trophic niches with smaller overlaps, suggesting greater specialization. Pasture sites had greater ranges of resources exploited, indicating higher trophic diversity than sites with natural cover and sugar cane plantation. We conclude that agricultural land uses appears to alter the food base and shift macroinvertebrate assemblages towards more generalist feeding behaviors and greater overlap of the trophic niches.
人们普遍认识到，溪流大型无脊椎动物的群落结构会随着集水区或当地土地利用的变化而改变。我们的目标是了解底栖大型无脊椎动物群落的营养生态学如何响应热带溪流中的土地利用变化。我们采用同位素方法来评估在受不同土地利用（自然覆盖、牧场、甘蔗种植园）影响的环境中，大型无脊椎动物之间的能量流动和营养关系是如何受到影响的。对大型无脊椎动物进行采样并归类为功能摄食组，同时对可用的营养资源进行采样，并评估位于塞拉多（新热带稀树草原）的溪流沿线13C和15N的同位素组成。受牧场或甘蔗影响的溪流具有更宽且重叠更多的营养生态位，这对应于更具通用性的摄食习性。相比之下，具有原生植被的溪流中的营养组具有更窄的营养生态位且重叠较小，表明其专业化程度更高。牧场区域利用的资源范围更大，表明其营养多样性高于具有自然覆盖和甘蔗种植园的区域。我们得出结论，农业土地利用似乎会改变食物基础，并使大型无脊椎动物群落转向更具通用性的摄食行为以及营养生态位的更大重叠。
