Ovo-viviparity in the Odonata? The case of <i>Heliocypha perforata</i> (Zygoptera: Chlorocyphidae)

<div><p>In this paper we record a likely instance of ovo-viviparity in a chlorocyphid damselfly from south-western China. If confirmed, this will be the first record of live birthing in the Odonata: indeed in any member of the Palaeoptera. The widespread Asian damselfly <i>Heliocypha perforata</i> (Percheron, 1835) is proposed to be, at least facultatively, viviparous. A female was observed and filmed appearing to deposit pro-larvae directly onto the exposed surface of a half-submerged branch in a small stream in Xishuangbanna Autonomous Dai Prefecture, Yunnan, China. The species is known to deposit eggs in bark crevices close to water but no previous case of actual live births is known.</p></div

Food web and host plant data

Food web data of leaf miner hosts and their parasitoids from sites making up elevational transects at three locations in eastern Australian, subtropical rainforest and associated host plant data

Size-Class Effect Contributes to Tree Species Assembly through Influencing Dispersal in Tropical Forests

<div><p>We have investigated the processes of community assembly using size classes of trees. Specifically our work examined (1) whether point process models incorporating an effect of size-class produce more realistic summary outcomes than do models without this effect; (2) which of three selected models incorporating, respectively environmental effects, dispersal and the joint-effect of both of these, is most useful in explaining species-area relationships (SARs) and point dispersion patterns. For this evaluation we used tree species data from the 50-ha forest dynamics plot in Barro Colorado Island, Panama and the comparable 20 ha plot at Bubeng, Southwest China. Our results demonstrated that incorporating an size-class effect dramatically improved the SAR estimation at both the plots when the dispersal only model was used. The joint effect model produced similar improvement but only for the 50-ha plot in Panama. The point patterns results were not improved by incorporation of size-class effects using any of the three models. Our results indicate that dispersal is likely to be a key process determining both SARs and point patterns. The environment-only model and joint-effects model were effective at the species level and the community level, respectively. We conclude that it is critical to use multiple summary characteristics when modelling spatial patterns at the species and community levels if a comprehensive understanding of the ecological processes that shape species’ distributions is sought; without this results may have inherent biases. By influencing dispersal, the effect of size-class contributes to species assembly and enhances our understanding of species coexistence.</p></div

Comparison of observed <i>g(r)</i> of species at DBH Class 0 (that is: size-classes 1, 2 and 3 combined) with <i>g(r)</i> simulated by three point process models with and without size-class effect.

<p>Abbreviations as for <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0108450#pone-0108450-g004" target="_blank">Figure 4</a>.</p

Boxplots of <i>AIC</i> value distributions of the SARs generated by the three process models for size-classes 1, 2 and 3 of the Bubeng plot and the BCI plot.

<p>HT = the homogeneous Thomas process; IP = the inhomogeneous Poisson process; IT = the inhomogeneous Thomas process.</p

The p-values of pairwise Wilcoxon rank sum tests on SAR and <i>g(r) AIC</i> values among the three point process models for the three DBH classes.

<p>Note: See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0108450#pone-0108450-t001" target="_blank">Table 1</a> for the abbreviations.</p><p>The p-values of pairwise Wilcoxon rank sum tests on SAR and <i>g(r) AIC</i> values among the three point process models for the three DBH classes.</p

The observed and predicted species–area curves for the three process models with and without the size-class effect for Class 0 (that is: size-classes 1, 2 and 3 combined) of the Bubeng plot and the BCI plot.

<p>The bars represent 95% confidence intervals.</p

The p-values from Kruskal-Wallis rank sum tests on SAR and <i>g(r) AIC</i> values across the point process models with and without size-class effect at DBH class 0 (that is: size-classes 1, 2 and 3 combined).

<p>Note: IP = the inhomogeneous Poisson process, HT = the homogeneous Thomas processt, IT = the inhomogeneous Thomas process.</p><p>The p-values from Kruskal-Wallis rank sum tests on SAR and <i>g(r) AIC</i> values across the point process models with and without size-class effect at DBH class 0 (that is: size-classes 1, 2 and 3 combined).</p

The observed and predicted species–area curves for the three process models for size-classes 1, 2 and 3 of the Bubeng plot and the BCI plot.

<p>The bars represent 95% confidence intervals.</p

Boxplots of <i>g(r) AIC</i> value distributions generated by the three processe models with and without the size-class effect at Class 0 (that is: size-classes 1, 2 and 3 combined) of the Bubeng plot and the BCI plot.

<p>Boxplots of <i>g(r) AIC</i> value distributions generated by the three processe models with and without the size-class effect at Class 0 (that is: size-classes 1, 2 and 3 combined) of the Bubeng plot and the BCI plot.</p