Ecological Archives M072-001-A5

Peter B. Pearman. 2002. The scale of community structure: habitat variation and avian guilds in tropical forest understory. Ecological Monographs 72:19-39.

Appendix E. Regression coefficients for square-root transformed species richness within several guilds of Amazonian understory birds.

A).
Guilds
Frugivores Large-insect insectivores  Ant-followers Hummingbirds Small  shrub-layer
foliage gleaners		 Omnivores Understory insectivores Understory probers of dead leaves Mixed-flock participants Ground Shrub Understory All non-canopy species
Environmental 
Variables:		 s-fr-f s-li-f s-li-r s-ni-f s-si-f s-so-f u-si-f u-li-d mxdflk        
FOREST 1
0.032
0.042 0.134 *** -0.00389 0.145 ** 0.092 *† 0.056 0.153 *** 0.129 ** 0.189*** 0.155** 0.201*** 0.239***
FOREST 2 -0.021 -0.12 0.023 0.143 (*) -0.019 0.15 0.115 0.245 ** 0.08 0.232(*) 0.078 0.257*† 0.195
CANOPY -0.002 0.16 0.362 *** 0.087 0.038 0.046 0.102 -0.018 0.129 -0.147 0.270* 0.194 0.258(*)
AREA  0.005 0 -0.943** -0.047 (*) 0.047 0.012 -0.058 0.271 0.014 -0.019 -0.048 -0.042 -0.066
TMAX -0.111 0.026 -0.288** -0.179 * -0.043 -0.077 -0.167 0.168 -0.008 -0.048 -0.343** -0.050 -0.300(*)
Intercept 1.175 -15.014 -32.416 *** -5.785 -2.618 -3.294 -8.833 2.622 -10.5 15.571 -21.428* -17.085 -19.629
B).
Polynomial Terms
x 0.107 -0.084 0.182 -0.068 0.347 ** 0.182 0.037 0.297 ** 0.240 * 0.383** 0.283* 0.345* 0.426**
y 0.0129 -0.084 0.792 ** 0.040 0.373 0.300 0.231 0.166 0.612 * 0.390 0.684* 0.794* 0.898**
x2 -0.061 -0.147 -0.189 * -0.001 -0.062 -0.025 0.054 0.052 -0.128 -0.117 -0.146 -0.054 -0.178
y2 -0.521 -0.230 -0.366 -0.141 -0.326 -0.200 -0.027 -0.606 * -0.305 -0.592(*) -0.488 -0.541 -0.698
xy -0.094 0.066 -0.245 -0.150 0.108 -0.064 -0.141 -0.166 -0.030 -0.428* -0.234 -0.253 -0.352
intercept 1.176 *** 0.910 *** 1.905 *** 2.102 *** 2.001 *** 1.417 *** 0.202 0.535 * 2.573 *** 1.367*** 4.597*** 1.491*** 5.109***

   Notes: Regression analyses were developed for two groups of variables separately, (A) environmental variables and (B) second order polynomial of centered site coordinates.  FOREST 1 and FOREST 2 are PCA sites scores on first two principal components of primary forest cover within tori around study sites.  CANOPY, AREA, and TMAX are percent canopy cover, total tree basal area, and maximum temperature measured at the study sites. Significance levels are (*) 0.07>P>0.05, * < 0.05, ** < 0.01, *** < 0.001.
  † Estimate became statistically significant after two environmental variables, understory density and relative humidity, were dropped from the model.


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