Deciphering Plant-Soil Water Interactions in Tropical Agroforestry Systems

Abstract:

Over the last decade, the use of hydrogen and oxygen water stable isotopes techniques in ecohydrological studies has helped to elucidate plant-soil and water dynamics across different ecosystems and environments. Recently, the incorporation of biophysical properties (roots and nutrients) as priors in plant water source models has improved our understanding of the processes that lead to differences in the depth of plant water uptake.

Arabica coffee sustains ~70% of the global coffee market, but its growth, yield and quality have been negatively affected by climate change. In response, plantation management practices have been incorporating new resistant coffee varieties to face twenty-first century environmental threats. However, the complex interactions among trees, coffee and soil water sources remain poorly investigated across different shade coffee systems. Hence, an observatory was established in central Veracruz, Mexico to investigate the ecohydrology of understudied tropical shade coffee environments.

This talk will show the dominant water sources for trees and coffee based on uninformative (isotopes) vs. informative (priors) mixing models; whether complementary water use strategies prevail over competition across dry and wet periods; and how these strategies might be affected with the introduction of new varieties and land practices. This knowledge is relevant for a wide range of managed plantations and serves coffee producers to make better decisions on sustainable coffee and water management under future climate.