Human land-uses drive assemblage taxonomic & functional
diversities
Despite considering environmental and climate-related biodiversity
predictors, intensive human land use was a key driver, accounting for
83%, 66% and 83% of the explained variance in taxonomic richness for
fish, arthropod, and macrophyte, respectively (Figure 2). Intensive
human land use also accounted for 74%, 36%, and 26% of the explained
variance in functional diversity for fish, arthropods, and macrophytes
(Figure 2). In particular, agriculture, pasture, and urbanization were
significantly and negatively related with taxonomic richness and
functional diversity of the three assemblages (Figure 3a, Table S6).
However, land-use types had contrasting effects on diversity components
of fish, arthropod and macrophyte. For instance, agriculture and
urbanization were most strongly associated with fish taxonomic richness,
whereas pasture and urbanization were most strongly associated with
arthropod and macrophyte taxonomic richness (Figure 3b). Similarly,
agriculture, pasture, and urbanization were most strongly associated
with fish functional diversity, whereas urbanization was most strongly
associated with functional diversity of arthropods, and agriculture was
most strongly associated with functional diversity of macrophytes
(Figure 3c).
Intensive human land use was also important in explaining the diversity
of the three trait categories (Table S7). Human land-use accounted for
43%, 24%, and 39% of the explained variance for recruitment and
life-history of fish, arthropod, and macrophyte respectively (Figure 4).
Similarly, human land-use explained 60%, 60%, and 26% of the variance
in diversity of resource and habitat-use for fish, arthropod, and
macrophyte (Figure 4). Lastly, human land-use explained 34%, 20% and
43% of the variance in diversity of body size for fish, arthropod, and
macrophyte (Figure 4). In general, agriculture and urbanization were
negatively associated with diversity of recruitment and life-history,
resource and habitat-use, and body size of three assemblages.
Afforestation was positively related with diversity of resource and
habitat-use of fish and arthropods (Figure 5a). Diversities of trait
categories of fish, arthropod, and macrophyte were also significantly
related to different land-use types (Figure 5b-d).