Different profiles of soil phosphorous compounds depending on tree species and availability of soil phosphorus in a tropical rainforest in French Guiana.

Background: The availability of soil phosphorus (P) often limits the productivities of wet tropical lowland forests. Little is known, however, about the metabolomic profile of different chemical P compounds with potentially different uses and about the cycling of P and their variability across space under different tree species in highly diverse tropical rainforests.

Results: We hypothesised that the different strategies of the competing tree species to retranslocate, mineralise, mobilise, and take up P from the soil would promote distinct soil P profiles.

Differential physiological and production responses of C3 and C4 crops to climate factor interactions.

This study examined the effect of the interactions of key factors associated with predicted climate change (increased temperature, and drought) and elevated CO concentration on C3 and C4 crop representatives, barley and sorghum. The effect of two levels of atmospheric CO concentration (400 and 800 ppm), three levels of temperature regime (21/7, 26/12 and 33/19°C) and two regimes of water availability (simulation of drought by gradual reduction of irrigation and well-watered control) in all combinations was investigated in a pot experiment within growth chambers for barley variety Bojos and sorghum variety Ruby. Due to differences in photosynthetic metabolism in C3 barley and C4 sorghum, leading to different responses to elevated CO concentration, we hypothesized mitigation of the negative drought impact in barley under elevated CO concentration and, conversely, improved performance of sorghum at high temperatures.

Grain carbon isotopes indicate the ability of wheat plants to maintain enhanced intrinsic water-use efficiency even after short-term exposure to high temperatures and drought.

Minimizing the impact of heat and drought on crop yields requires varieties with effective protective mechanisms. We tested the hypothesis that even a short-term high temperature amplifies the negative effects of reduced water availability on leaf gas-exchange, but can induce long-lasting improvement in plant water-use efficiency after the stress period. Accordingly, three common varieties of winter wheat (Triticum aestivum) were grown under field conditions.

Growth, physiology, and stomatal parameters of plant polyploids grown under ice age, present-day, and future CO concentrations.

Polyploidy plays an important role in plant evolution, but knowledge of its eco-physiological consequences, such as of the putatively enlarged stomata of polyploid plants, remains limited. Enlarged stomata should disadvantage polyploids at low CO concentrations (namely during the Quaternary glacial periods) because larger stomata are viewed as less effective at CO uptake. We observed the growth, physiology, and epidermal cell features of 15 diploids and their polyploid relatives cultivated under glacial, present-day, and potential future atmospheric CO concentrations (200, 400, and 800 ppm respectively).

Leaf Functional Traits in Relation to Species Composition in an Arctic-Alpine Tundra Grassland.

The relict arctic-alpine tundra provides a natural laboratory to study the potential impacts of climate change and anthropogenic disturbance on tundra vegetation. The -dominated relict tundra grasslands in the Krkonoše Mountains have experienced shifting species dynamics over the past few decades. Changes in species cover of the four competing grasses-, , , and -were successfully detected using orthophotos.