8 research outputs found
Posterior predictive checks of the HB model.
<p>We calculated three test statistics: 1) Pearson’s <i>r<sup>2</sup></i> assessing the correlation between the observed data and the replicated data, 2) to assess the ability of the model to capture the mean tendency of the data, and 3) based on a sums-of-squares approach to assess overall model fit including its ability to capture data variability. A value of (for both <i>mean</i> and <i>fit</i>) near 0 or 1 indicates lack of fit; values near 0.5 are acceptable.</p
Site characteristics.
<p>Woody cover was measured and domestic animal density provisionally estimated in 2008. Fire frequency was extracted from continental-scale data and thus shows broad patterns.</p
Fitted allometries for each allometric relationship using global level parameters.
<p>The symbols correspond to species as according to the legend and are semi-transparent to show overlapping points. Lines show global level (interspecific) mean fit and the shaded regions are the 95% credible intervals. Note that all plots are in log-log space. Species codes: demi, <i>Detarium microcarpum</i> (MAP = 1400 mm yr<sup>−1</sup>); coge, <i>Combretum geitynophylum</i> (MAP = 1200 mm yr<sup>−1</sup>); cogl, <i>Combretum glutinosum</i> (MAP = 570 mm yr<sup>−1</sup>).</p
Variance components of the hierarchical Bayesian model for each scaling relationship (diameter vs. trait).
<p>Means are shown with 95% credible intervals displayed in parentheses.</p
Model predictions for scaling exponents (<i>b</i>).
<p>The scaling exponents all refer to <i>b</i> in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058241#pone.0058241.e002" target="_blank">Equation 1</a> where the dependent variable (<i>X</i>) is diameter. For example, the 2/3 in upper-left cell shows that under Metabolic Scaling Theory length is proportional to diameter to the 2/3 power (<i>lD<sup>2/3</sup></i>).</p
Posterior means and 95% credible intervals of scaling exponents (<i>b</i>) at different hierarchical levels.
<p>Symbols correspond to the species and the large diamond represents the interspecific, global-level scaling exponent. 95% credible intervals are shown as vertical lines on means. The levels along the x-axis refer to levels in the hierarchical Bayesian model. The horizontal lines represent the theoretical predictions of the three scaling models (note that in D MST and GEOM make the same prediction, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058241#pone-0058241-t001" target="_blank">Table 1</a>). Species codes are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058241#pone-0058241-g001" target="_blank">Figure 1</a>. AG mass = aboveground mass.</p
Species level posterior means and 95% credible intervals of normalization constants (<i>a</i>).
<p>Species codes are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058241#pone-0058241-g001" target="_blank">Figure 1</a> and “Traits” along x-axis refer to the scaling of diameter with that trait (e.g., “length” refers to the normalizing constants for the scaling relationship <i>l</i> = <i>aD<sup>b</sup></i>). Symbols correspond to the species and 95% credible intervals are shown as vertical lines on means.</p
Trait data
Venation, trait, and climate data for tree species on an Andes-Amazon transect in southeastern Peru (CHAMBASA project)