Physiological plasticity in eucalyptus clones in the vegetative stage contributes to drought tolerance

With the expansion of eucalyptus crops to areas with severe water limitations,physiological studies involving eucalyptus clones to identify those that are tolerant to water stress become important.The objective of this study was to assess morphological and physiological responses by eucalyptus clones subjected to drought stress and rehydration.The experiment consisted of three eucalyptus clones:VC865,I224 and I144 and two water regimes:control and water stress followed by rehydration,with six replicates.Leaf water potential,gas exchange,maximum quantum efficiency of photo systemⅡand plant height and stem diameter were evaluated under drought stress and rehydration.After6 d of rehydration,the number of leaves,leaf area and dry mass of root,leaf,stem and their total were evaluated.All clones showed intense reduction of gas exchange during the drought stress period,and only VC865 and 1144 showed rapid recovery with 3 d of rehydration.Clone 1224 showed greater reduction in height,stem diameter,number of leaves,water potential at midday(Ψ_(w)_(Midday)),and maximum quantum efficiency of photosystemⅡ(F_(v)/F_(m)).Clones VC865and T144 showed lower reductions inΨ_(wMidday)and F_(v)/F_(m) under stress.VC865 had lower reductions in leaf number,leaf area and higher leaf dry mass,while clone I144 had higher height and lower reduction in root dry mass under.Both these clones showed higher water use efficiency with 3d of rehydration.These different phenotypic plasticities gave the clones VC865 and 1144 efficient mechanisms of acclimatization to stress and more drought tolerance,enhancing their greater capacity for recovery after stress,which allowed lower dry mass reduction.Clone 1224,however,was more susceptible to drought stress,undergoing greater physiological damage with only partial recovery during rehydration.

The Bird Community in a Threatened Coastal Lagoon in Southeastern Brazil

We provide a list of bird species for Ribeira lagoon, a protected area in Rio de Janeiro, southeastern Brazil. Data were obtained in monthly surveys in points along a continuous transect, between August 2008 and July 2009, and 21 ad libitum observations. In total, 174 species were listed, including 121 land birds and 53 waterbirds. Of these, 11 are considered threatened at regional level. Waterbird richness was significantly higher in the dry season (April to September) than in the rainy season (October to March), whereas land bird richness remained constant. However, land bird richness varied throughout the year, with the highest value in February 2009 (77 species) and the lowest in May 2009 (41 species). The species listed account for 23% of the total of 745 bird species listed for Rio de Janeiro, and for 49% of 108 waterbirds recorded for the state.

Flight performance and wing morphology in the bat Carollia perspicillata:biophysical models and energetics

Studies on functional performance are important to understand the processes responsible for the evolution of diversity.Morphological trait variation within species influences the energetic cost of locomotion and impacts life history traits,with ecological and evolutionary consequences.This study examined wing morphology correlates of flight performance measured by energetic expenditure in the Seba’s short-tailed bat,Carollia perspicillata.In the flight experiments,nature caught bats(59 females,57 males)were allowed to fly for 3 min in a room.After each flight,thermographic images were taken to measure body temperature,and biophysical models were used to calculate sensible heat loss as a measure of energetic expenditure.Wing morphological traits were measured for each individual and associated with heat loss and power required to fly on performance surfaces.Wing morphological traits explained 7-10%of flight energetic cost,and morphologies with the best performance would save the energy equivalent to 9-30%of total daily requirements.The optimal performance areas within the C.perspicillata morphospace were consistent with predicted selection trends from the literature.A trade-off between demands for flight speed and maneuverability was observed.Wing loading and camber presented sexual dimorphism.These morphological differences are likely associated with more economical but less maneuverable flight in females,leading them to fly more often in open areas along the forest edge.Our findings demonstrate how small scale changes in wing morphology can affect life history strategies and fitness.