Ecologists use a rank-abundance curve to display relative species abundance, which is a component of biodiversity. It can also be used to demonstrate species richness and evenness. Figure 1 shows the...

Extracted text: Ecologists use a rank-abundance curve to display relative species abundance, which is a component of biodiversity. It can also be used to demonstrate species richness and evenness. Figure 1 shows the rank- abundance curve for caddisflies (Order Trichoptera) of two aquatic habitats in northern Portugal (data from L.S.W. Tera). Pollution of streams, on the other hand, reduces the diversity of Trichoptera and several other groups of stream insects, reducing both species richness and species diversity. Interpret why those happened. These rank-abundance curves show that the mountain stream caddisfly community has higher species richness and greater species evenness. 0.1 - Mountain stream 0.01 Greater richness and species evenness 0,001 Coastal ponds 0.0001 20 40 60 80 Abundance rank Figure 1: Rank-abundance curve for caddisflies (Order Trichoptera) of two aquatic habitats in northern Portugal (data from L.S.W. Tera). Proportional abundance