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Land use change affects macroinvertebrate community size spectrum in streams: the case of Pinus radiata plantations
Author(s) -
Martínez Aingeru,
Larrañaga Aitor,
Miguélez Andrea,
YvonDurocher Gabriel,
Pozo Jesús
Publication year - 2016
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1111/fwb.12680
Subject(s) - streams , deciduous , ecology , pinus radiata , guild , trophic level , detritivore , environmental science , vegetation (pathology) , generalist and specialist species , predation , invertebrate , biology , habitat , medicine , computer network , pathology , computer science
Summary In low‐order forested streams, catchment‐scale land‐use modifications to vegetation can affect energy inputs into streams and trophic interactions within these donor‐controlled food webs. We examined the effects of Pinus radiata plantations on the intercept and slope of the size spectrum (the relationship between log‐mass and log‐density) of macroinvertebrate communities in low‐order forested streams. We compared three streams draining pine plantations with three draining native deciduous forests, all without significant differences in water physicochemical characteristics. While size spectrum intercept was similar between the two stream types, the slope of the size spectrum was shallower in pine than in deciduous streams based on a decline in the density of the smaller individuals. The shredder feeding guild showed the largest changes, with a significant reduction in their total density and, specifically, in the density of the smaller individuals from the deciduous to the pine streams. This alteration is explained by the change in very specialist shredders, such as plecopterans and trichopterans, but not in those with highly mobile crustaceans or more generalist dipterans. The effect detected for shredders might have scaled up to higher trophic levels as the density of invertebrate predators (small and big) was lower in streams under pine, suggesting a response to prey limitation. These results indicate that the change of in‐stream resource quality arising from the replacement of deciduous vegetation by pine plantations can trigger size‐specific responses of macroinvertebrates and target specialised feeding guilds such as shedders, and can elicit a bottom‐up reaction in the organisation of food webs.