Fig. 2: Fish species traits in relation to terrestrial LULC types in the Chao Phraya catchment.
From: Terrestrial land cover shapes fish diversity in a major subtropical river catchment
Fish species functional traits and water properties including chlorophyll-a (Chl-a), total suspended solids (TSS), and dissolved organic carbon (DOC) in relation to rainfed cropland (a), irrigated cropland (b), forest (c), shrub- and grassland (d), and urban (e) land use and land cover (LULC) types, respectively, across the Chao Phraya catchment. The associated LULC for fish species was determined by the highest terrestrial LULC effect (Vk) value from species-level (presence/absence) modeling. The trait space envelopes of LULC-associated fishes were created based on the FISHMORPH database with a principal component analysis of the functional trait space of fish species. Maximum body length (MBl), body elongation (BEl), vertical eye position (VEp), relative eye size (REs), oral gape position (OGp), relative maxillary length (RMl), body lateral shape (BLs), pectoral fin vertical position (PFv), pectoral fin size (PFs), and caudal peduncle throttling (CPt) were used to create fish trait space. Distinct fish trait space envelopes were observed among the five LULC types. Water properties were estimated from Sentinel-2 data based on the major river channel pixels with a river width >60 m, and were min-max scaled for plotting. There was no data on water properties for shrub- and grassland types. The error bars indicate the standard deviation. These figures illustrate that rivers in forested areas tend to have lower Chl-a, TSS, and DOC values, thereby less resource or nutrient subsidies compared with cropland and urban areas.
