Freshwater vertebrate and invertebrate diversity patterns in an Andean-Amazon basin: implications for conservation efforts

Figures & data

Figure 1. Study area, the Napo Basin in Ecuador. (A) Altitudinal gradient, main rivers, floodplains systems, and some main rivers and cities in the basin. (B) Location of all vertebrate species records obtained from museum databases and online data-sets, and (C) sampling localities surveyed for freshwater invertebrates and amphibians during this study.

Table 1. Environmental data layers used in the species and family distribution models.

Variable	Description	Data source
Climatic
Annual maximum temperature	Air temperature was used as a substitute for water temperatures, since these two variables are usually strongly positively correlated in regional and large-scale studies [102]	Ministerio del Ambiente del Ecuador [35]
Annual minimum temperature
Annual precipitation	The precipitation has an important influence in the water regimes, flow rivers, and flood process	Ministerio del Ambiente del Ecuador [35]
Topographic
Elevation (DEM)	Elevation and slope are important in describing the hydrological characteristics of the river, providing favorable or non-favorable habitats [103]	SRTM (http://srtm.csi.cgiar.org/)
Slope		Derived from DEM
Aspect	Aspect is an important contributor to vegetation and habitat type, as north-facing slopes often have very different conditions and temperatures than south-facing slopes [87]	Derived from DEM
Hydrologic
Topographic wetness index	This index involves the upslope contributing area (a), a slope, and a couple of geometric functions. Higher values represent drainage depressions and more wetness	Derived from DEM
General curvature	The curvatures indicate the concavity or convexity of regions, and where running water would converge, diverge, accelerate or decelerate as it flows over the region [87]	Derived from DEM
Longitudinal Curvature
Cross-sectional curvature
Average of flow accumulation in microbasins	The flow accumulation represents the potential water accumulation in the stream channels	Derived from DEM
Drainage density in microbasins	The drainage density has been determined as influent in the fish distributions.[104] For each microbasin we divide the total stream length (km) by microbasin area (km^2)	Derived from DEM
Microbasin size	The watershed area is related to river size and strongly influences stream fish assemblages [104]	IGM (www.igm.gob.ec)
Floodplains (categorical)	The floodplains systems may have different species compositions given their difference in the hydrological regimes. Floodplain zones: lakes and lagoons and other flooded areas by more than 8 months. Floodable zones: seasonally flooded with water from overflowing rivers or local precipitation. Zones susceptibility to flood: occasionally they may be flooded due to overflowing rivers or high rainfall events	Ministerio del Ambiente del Ecuador [35]
Landscape
Ecosystems (categorical)	The ecosystems indicate important aspects of the different habitats and the zones with different “type of waters”, which influence the distribution of aquatic species	Sierra [105]
Geomorphology (categorical)	Describe the three-dimensional landscape (geoforms) characterized by one or more morphometric, lithological and structural attributes. The geomorphology influences the distribution of species and ecosystems at multiple scales	Ministerio del Ambiente del Ecuador [35]

Figure 2. Species richness for freshwater vertebrates in the Napo Basin. Species richness maps were obtained from the summation of the species distribution models of (A) all species, (B) amphibians, (C) birds, (D) mammals, (E) reptiles, and (F) fish. Main state protected areas in the Napo Basin are: Yasuní National Park (Y NP), Cuyabeno Faunistic Reserve (C FR), Cayambe Coca National Park (CC NP), Sumaco Napo-Galeras National Park (SN NP), Antisana Ecological Reserve (A ER), Colonso-Chalupas Biological Reserve (CC BR), and Llanganates National Park (L NP).

Figure 3. Family richness for freshwater invertebrates in the Napo Basin. This map was obtained from the summation of 54 invertebrate family distribution models. Main state protected areas in the Napo Basin are: Yasuní National Park (Y NP), Cuyabeno Faunistic Reserve (C FR), Cayambe Coca National Park (CC NP), Sumaco Napo-Galeras National Park (SN NP), Antisana Ecological Reserve (A ER), Colonso-Chalupas Biological Reserve (CC BR), and Llanganates National Park (L NP).

Table 2. Correlation tests for species richness between pairs of freshwater vertebrate taxa in the entire Napo Basin and by altitudinal zone.

Altitudinal level	Amphibians	Birds	Mammals	Reptiles	Fish	Average
Napo Basin						0.66 (SD 0.11)
Amphibians	–	0.61 ^ns	0.56^**	0.68^**	0.81^**	0.67 (SD 0.11)
Birds	0.61^ns	–	0.54 ^ns	0.49^**	0.78^*	0.61 (SD 0.13)
Mammals	0.56^**	0.54^ns	–	0.58^**	0.75^**	0.61 (SD 0.10)
Reptiles	0.68^**	0.49^**	0.58^**	–	0.76^**	0.63 (SD 0.12)
Fish	0.81^**	0.78^*	0.75^**	0.76^**	–	0.78 (SD 0.03)
Lowlands (<600 m)						0.58 (SD 0.18)
Amphibians	–	0.25^*	0.51^*	0.67^**	0.57^**	0.50 (SD 0.18)
Birds	0.25^*	–	0.51^**	0.38^**	0.63^**	0.44 (SD 0.16)
Mammals	0.51^**	0.51^*	–	0.64^**	0.85^**	0.63 (SD 0.16)
Reptiles	0.67^**	0.38^**	0.64^**	–	0.80^**	0.62 (SD 0.18)
Fish	0.57^**	0.63^**	0.85^**	0.80^**	–	0.71 (SD 0.13)
Lower montane forests (600–1600 m)						0.39 (SD 0.19)
Amphibians	–	0.29^**	0.33^**	0.62^**	0.58^**	0.45 (SD 0.17)
Birds	0.29^**	–	0.05^ns	0.29^**	0.31^**	0.23 (SD 0.12)
Mammals	0.33^**	0.05^ns	–	0.50^**	0.32^**	0.30 (SD 0.19)
Reptiles	0.62^**	0.29^**	0.50^**	–	0.66^**	0.52 (SD 0.17)
Fish	0.58^**	0.31^**	0.32^**	0.66^**	–	0.46 (SD 0.18)
Upper montane forests (>1600 m)						0.14 (SD 0.36)
Amphibians	–	0.13^ns	−0.51^**	0.52^**	0.45^**	0.15 (SD 0.47)
Birds	0.13^ns	–	−0.02^*	0.28^ns	0.25^**	0.16 (SD 0.14)
Mammals	−0.51^**	−0.02^*	–	−0.19^**	−0.16^**	−0.22 (SD 0.21)
Reptiles	0.52^**	0.28^ns	−0.19^**	–	0.65^**	0.32 (SD 0.37)
Fish	0.45^**	0.25^**	−0.16^**	0.65^**	–	0.30 (SD 0.35)

Notes:

Results of significance tests are corrected for spatial autocorrelation. **p < 0.005 (Bonferroni correction); *p < 0.05; ns, not significant.

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