PS 83-7
Trait responses of macroinvertebrate communities to land use impacts: An approach for freshwater biomonitoring in Mongolia

Friday, August 14, 2015
Exhibit Hall, Baltimore Convention Center
Oyunchuluun Yadamsuren, Department of Biology, Mongolian National University of Education, Ulaanbaatar, Mongolia

Land-use practices in Mongolia lead to habitat degradation and consequently affect the structure and function of biological communities. It is required to determine the ecological consequences of habitat degradation on biological communities due land use impact in Mongolia.

The main aim this study was to determine land-use effects on macroinvertebrate communities based on their response to grazing and mining using trait-based approach.     

At 42 site, 20 D-net composite samples were taken from a variety of microhabitats respectively its percentage in the 50 m reach. Then pooled samples of 200 macroinvertebrates were randomly picked. Insects were identified to genus level. Non-insect groups identified to family level.

Twelve different physico-chemical variables measured using a spectrophotometer. Stream habitat was assessed using US EPA Protocol metrics. To estimate grazing intensity, a visual assessment of % ground cover type and a measurement of vegetation height were taken in the riparian zone at 3 distances from the stream using 1 sqm frame. The functional structure of macroinvertebrate communities was examined using 86 categories of 16 traits. Trait states were coded with “fuzzy” code.

The JMP software version 9.0.2 (SAS Institute Inc. 2010) was used for PCA and ANOVA, f-diversity software (Casanoves et al. 2011) for computing functional diversity indices, and R software version 3.0.1 for conducting a vegan package (R Development Core Team 2010) for CCA analysis and permutational MANOVA.


For individual trait community weighted mean (CWM), 19 trait categories of 11 traits was significantly different among sites with different level of land-use intensity. Significant declines in functional diversity were observed by TBA with greater levels of land use intensity (more grazing and mining), and 13 of 16 traits (such as reproduction, life stages, resistant form, dissemination method, locomotion and substrate relation, feeding habit, food, saprobity, temperature, trophic level, current velocity, and substrate preferendum) varied significantly among different levels of land-use intensity. There were no significant differences observed among traits associated with an r/K reproductive strategy (body size, life span and voltinism) among the sites.

A majority of variation of community traits was explained by local environmental variables.

The study result showed a strong relationship the between functional structure of the macroinvertebrate community and habitat conditions. TBA clearly discriminated seminatural sites from sites with greater level of land-use intensity because traits are specifically correlated with environmental conditions, their presence and frequency provided a more direct explanation for macroinvertebrate responses to land-use.