Microclimate and sapling survival under organic and polyethylene mulch in a tropical dry deciduous forest

Abstract

Mulches effect on net radiation (RN), air (Ta) and soil (TS) temperature, vapour pressure deficit (VPD), soil water content (SW), stomatal conductance (gS) and survival of three native species in a degraded tropical deciduous forest area was examined. The study year was dry, with half of the average annual rainfall. Three blocks were chosen, each block contained sixteen plots. Mulches with alfalfa straw, forest litter, white polyethylene and bare soil, were used. Twenty plants of each species one year-old were transplanted in each of 16 plots (5 × 6 m). The experiment was conducted during one year. RN was higher in plots with forest litter than in other treatments; Ta, TS and VPD were higher in bare soil plots than in mulched plots, and SW was higher in mulched plots than in bare soil plots. Ipomoea wolcottiana and Caesalpinia eriostachys registered the highest values of gS and survival, whilst Lonchocarpus eriocarinalis registered the lowest. In polyethylene mulch the three species showed the greatest survival. Mulches mitigate extreme microclimates and increase plant survival during the restoration of dry tropical areas.