Figure 1. A pair of Mute Swans (Cygnus olor ) inhabits at Wuliangsuhai Lake, Inner Mongolia
Figure 2. Locations of the 35 surveyed lakes and reservoirs in North China. Elevation gradient is used as background
Figure 3. Map of the 35 surveyed lakes and reservoirs in North China showing (a) waterbirds species richness, (b) functional richness, and (c) lake productivity (mg.m-3)
Figure 4. Patterns of species richness and lake productivity with environmental variables. Species richness of waterbirds as a function of (a) latitude, (b) longitude, and (c) altitude. Lake productivity (measured as chlorophyll a ) as a function of (d) total nitrogen, (e) total phosphorus Data points correspond to individual lakes. Regression lines show best liner fits. All regression lines are significant (P <0.05)
Figure 5. SEM for lake productivity. Latent variables are in ovals and measured variables in rectangles. The strength of the causality (standardized path coefficient) is indicted by the width of the line. Black lines indicate positive effects while red lines mean negative impacts. T1: mean diurnal range, T2: mean temperature of the wettest quarter, T3: mean temperature of the warmest quarter, P1: annual total precipitation, P2: precipitation of the driest month, P3: precipitation of the warmest quarter, and P4: precipitation of the coldest quarter
Figure 6. SEM model for waterbirds functional diversity. Latent variables in ovals and measured variables in rectangles. The strength of the causality (standardized path coefficient for direct comparison) was indicted by the width of the link. Black lines indicate positive effects while red lines mean negative impacts. T1: mean diurnal range, T2: mean temperature of the wettest quarter, T3: mean temperature of the warmest quarter, P1: annual total precipitation, P2: precipitation of the driest month, P3: precipitation of the warmest quarter, and P4: precipitation of the coldest quarter
Figure 7. Integrated SEM model in which waterbirds functional diversity is linked with lake productivity. Latent variables are in ovals and measured variables in rectangles. The strength of the causality (standardized path coefficient) was indicted by the width of the link. Black lines indicate positive effects while red lines mean negative impacts. T1: mean diurnal range, T2: mean temperature of the wettest quarter, T3: mean temperature of the warmest quarter, P1: annual total precipitation, P2: precipitation of the driest month, P3: precipitation of the warmest quarter, and P4: precipitation of the coldest quarter