RUBBER TREE AND CLIMATE CHANGES

The intensification of anthropogenic activities has resulted in a significant increase in greenhouse gas concentrations, altering thermal and rainfall regimes and consequently the water balance, which can influence the growth and development of plants. It is important to understand the impact of these climate changes on commercial forest species.

Thus, master's student Erilva Machado Costa developed her dissertation with the aim of evaluating the initial growth and determining physiological patterns of rubber tree clones under adverse climatic conditions. For this purpose, two experiments were established to evaluate the influence of CO2 concentrations and different water regimes in contrasting microclimates.

Erilva's research showed that rubber tree clones exhibited greater growth, higher rates of CO2 net assimilation, and intrinsic water use efficiency with increasing CO2 concentration, regardless of the studied microclimates, when there was no water deficit. Through the growth and physiological response variables, it became evident that the evaluated clones are more sensitive to microclimate conditions with low atmospheric demand, regardless of [CO2], as evidenced by the analyses of the A/FFFA and A/Ci curves, where clones exhibited higher photosynthetic performance in response to light when maintained under high atmospheric demand. However, withdrawing 50% of the available soil water for both clones was sufficient to reduce growth, demonstrating the high susceptibility of clones to water deficit. However, there was a difference between the studied genetic materials, as clone FX 3864 showed greater tolerance to reduced water availability compared to clone RRIM 600.

Erilva's research is very important because, working with seedlings, she was able to signal the impact of climate change on two widely cultivated rubber tree clones in Brazil. This will assist future silvicultural management and genetic improvement projects aimed at mitigating the effects of temperature changes and rainfall patterns on crops aimed at natural rubber production.

More details can be found in the student's complete dissertation on our website and in the article published in the Bioscience Journal.