Potential vulnerability to climate change of four tree species from the central mountain region of Veracruz, Mexico

Abstract

We define vulnerability here as the extent to which climate change may damage or harm a system, depending not only on a system's sensitivity, but also on its ability to adapt to new climatic conditions. Current climate change has already affected the Earth's biodiversity, and the rate of change is likely to accelerate in the future. It is expected that climate change will affect the performance, structure and distribution of ecosystems, species and genetic constituents. Changes in temperature and precipitation, and in the frequency and intensity of extreme events, can directly influence ecosystem functioning. To determine the vulnerability or fragility of different species to climate change, we used the envelope function method, because of its capacity to analyze the variables that directly affect different species; by measuring the effect of climate variables on stomatal conductance, this provided an effective analysis of the diversity of eco-physiological responses. Using this method to assess vulnerability helped us predict the extreme values that the species could tolerate; and also gave information about the species' sensitivity. We analyzed the effects of air temperature, photosynthetically active radiation, vapor pressure deficit and leaf water potential on the stomatal conductance in 4 tree species (Alnus acuminata, Quercus xalapensis, Liquidambar styraciflua and Pinus ayacahuite) from different altitudinal ranges in the central region of Veracruz, Mexico, in Las Grandes Montañas. Knowing how vulnerability affects the species and ecosystems is a key element of maintaining regional biodiversity.

Socio-economic vulnerability to climate change in the central mountainous region of eastern Mexico

“…Yet, these climate conditions may respond to other factors such as changes in land use, human settlements, and global and regional climate change. Previous studies from the region found increases in temperature (Esperón-Rodríguez and Barradas 2014a) and decreases in precipitation implying potential reductions of as much as 50 % by the year 2023 (Barradas et al 2010). Also, an increase in consecutive dry days was predicted (Esperón-Rodríguez and Barradas 2014b).…”

Ecophysiological Vulnerability to Climate Change in Mexico City’s Urban Forest

“…A direct effect of the increase in air temperature is the increase in VPD when water is limited and relative humidity is low. The response of g S to high temperatures can be uncertain, particularly when these temperatures are coupled with low relative humidity and high VPD (Medlyn et al, 2002;Esperon-Rodriguez and Barradas, 2014). The increase in VPD restricts g S , thus, species capable of maintaining stomata open when VPD is high are less vulnerable (i.e., Q. rugosa, E. camaldulensis and B. cordata).…”

“…The boundary-line analysis assesses the relationship between g S and climatic/environmental and physiological variables (i.e., T A , PAR, VPD, ψ). From this analysis, graphs are generated representing the optimal stomatal response to a given selected variable (Jarvis, 1976;Fanjul and Barradas, 1985;Jones, 1992;Barradas et al, 2004;Esperon-Rodriguez and Barradas, 2014). The analysis of the effect of each variable on stomatal conductance is determined with simple models that are referred to as boundary-line functions.…”

(Re)Designing Urban Parks to Maximize Urban Heat Island Mitigation by Natural Means

“…In general, high E and g S are related to sufficient irradiance (PAR ≥ 300 µmol m −2 s −1 ) on leaves to stimulate stomatal opening by raising leaf temperature [43,44], while a moderate VPD prevents stomatal closure produced by the influence of dry air and high pressure of humid air [45,46]. However, for these conditions to occur, plants must have water available in the soil.…”