Geographic parthenogenesis in a tropical forest tree

A new hypothesis to explain geographic parthenogenesis

In many plants and animal species, asexuals are more common in marginal habitats such as high latitudes or altitudes than their closely related sexual counterparts. Here we propose a new hypothesis to explain this pattern called “geographic parthenogenesis”. In marginal habitats, populations may often exist as metapopulations with high degrees of subdivision and local extinction and recolonizat...

Patterns of Tree Mortality in a Monodominant Tropical Forest

Tree dispersion, abundance, and diversity in a tropical dry forest.

Patterns of tree abundance and dispersion in a tropical deciduous (dry) forest are summarized. The generalization that tropical trees have spaced adults did not hold. All species were either clumped or randomly dispersed, with rare species more clumped than common species. Breeding system was unrelated to species abundance or dispersion, but clumping was related to mode of seed dispersal. Juven...

Geographic Parthenogenesis: Recurrent Patterns Down Under

A recent study reports striking similarities in the origin and spread of parthenogenesis in two distantly related animals of the Australian arid zone, suggesting that the loss of sex was driven by a very general selective force.

Photosynthetic acclimation to warming in tropical forest tree seedlings

Tropical forests have a mitigating effect on man-made climate change by acting as a carbon sink. For that effect to continue, tropical trees will have to acclimate to rising temperatures, but it is currently unknown whether they have this capacity. We grew seedlings of three tropical tree species over a range of temperature regimes (TGrowth = 25, 30, 35 °C) and measured the temperature response...