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Cruaud A.,French National Institute for Agricultural Research | Ronsted N.,Jodrell Laboratory | Ronsted N.,University of Minnesota | Ronsted N.,Entrance | And 29 more authors.
Systematic Biology | Year: 2012

It is thought that speciation in phytophagous insects is often due to colonization of novel host plants, because radiations of plant and insect lineages are typically asynchronous. Recent phylogenetic comparisons have supported this model of diversification for both insect herbivores and specialized pollinators. An exceptional case where contemporaneous plant-insect diversification might be expected is the obligate mutualism between fig trees (Ficus species, Moraceae) and their pollinating wasps (Agaonidae, Hymenoptera). The ubiquity and ecological significance of this mutualism in tropical and subtropical ecosystems has long intrigued biologists, but the systematic challenge posed by 750 interacting species pairs has hindered progress toward understanding its evolutionary history. In particular, taxon sampling and analytical tools have been insufficient for large-scale cophylogenetic analyses. Here, we sampled nearly 200 interacting pairs of fig and wasp species from across the globe. Two supermatrices were assembled: on an average, wasps had sequences from 77 of 6 genes (5.6 kb), figs had sequences from 60% of 5 genes (5.5 kb), and overall 850 new DNA sequences were generated for this study.We also developed a newanalytical tool, Jane 2, for event-based phylogenetic reconciliation analysis of very large data sets. Separate Bayesian phylogenetic analyses for figs and fig wasps under relaxed molecular clock assumptions indicate Cretaceous diversification of crown groups and contemporaneous divergence for nearly half of all fig and pollinator lineages. Event-based cophylogenetic analyses further support the codiversification hypothesis. Biogeographic analyses indicate that the present-day distribution of fig and pollinator lineages is consistent with a Eurasian origin and subsequent dispersal, ather than with Gondwanan vicariance. Overall, our findings indicate that the fig-pollinator mutualism represents an extreme case among plant-insect interactions of coordinated dispersal and long-term codiversification. [Biogeography; coevolution; cospeciation; host switching; long-branch attraction; phylogeny.] © 2012 The Author(s).

Wang D.-J.,Key Laboratory of Tropical Forest Ecology | Shen Y.-X.,Key Laboratory of Tropical Forest Ecology | Huang J.,Stone Forest Scenic Area Administration | Li Y.-H.,Yunnan Normal University
Environmental Science and Pollution Research | Year: 2016

The emergence of rock outcrops is very common in terrestrial ecosystems. However, few studies have paid attention to their hydrological role in the redistribution of precipitation, especially in karst ecosystems, in which a large proportion of the surface is occupied by carbonate outcrops. We collected and measured water received by outcrops and its subsequent export to the soil in a rock desertification ecosystem, an anthropogenic forest ecosystem, and a secondary forest ecosystem in Shilin, China. The results indicated that outcrops received a large amount of water and delivered nearly half of it to nearby soil patches by means of runoff. No significant difference was found in the ratio of water received to that exported to the soil by outcrops among the three ecosystems annually. When the outcrop area reaches 70 % of the ground surface, the amount of water received by soil patches from rock runoff will equal that received by precipitation, which means that the soil is exposed to twice as much precipitation. This quantity of water can increase water input to nearby soil patches and create water content heterogeneity among areas with differing rock emergence. © 2016 Springer-Verlag Berlin Heidelberg

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