Location: Soil, Water & Air Resources ResearchTitle: Land restoration by tree planting in the tropics and subtropics improves soil infiltration, but some critical gaps still hinder conclusive results
|LOZANO, SERGIO - UNIVERSIDADE DE SAO PAULO|
|COOPER, MIGUEL - UNIVERSIDADE DE SAO PAULO|
|MELI, PAULA - UNIVERSIDADE DE SAO PAULO|
|FERRAZ, SILVIO - UNIVERSIDADE DE SAO PAULO|
|RODRIGUES, RICARDO - UNIVERSIDADE DE SAO PAULO|
|Sauer, Thomas - Tom|
Submitted to: Forest Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/22/2019
Publication Date: 4/30/2019
Citation: Lozano-Baez, S.E., Cooper, M., Meli, P., Ferraz, S.F.B., Rodrigues, R.R., Sauer, T.J. 2019. Land restoration by tree planting in the tropics and subtropics improves soil infiltration, but some critical gaps still hinder conclusive results. Forest Ecology and Management. 444:89-95. https://doi.org/10.1016/j.foreco.2019.04.046.
Interpretive Summary: Forests have a strong influence on how much rainfall infiltrates into the ground. The trees intercept some of the rainfall, the mulch on the soil surface absorbs some water, and the tree roots help build soil organic matter that increases the amount of water that can be stored in the soil. The review article summarizes research on changes in infiltration when trees are replanted onto crop or pasture lands in the tropics that had previously been cleared of trees. Eleven studies in eight countries were identified that made infiltration measurements on restored forests. Several factors that affect infiltration were considered and it was concluded that soils with greater than 30% clay had greater increases in infiltration rate following tree planting. Six recommendations were made for future studies and much more data is needed to improve recommendations for improving infiltration following forest restoration. This research will help scientists, policymakers, and field technical staff make better decisions regarding land use change and its effects on infiltration and soil quality.
Technical Abstract: Infiltration of rainfall is one of the most important hydrological processes with important influence on soil erosion, runoff, soil moisture content and groundwater recharge in ecosystems. This is particularly important in forest restoration contexts, considering the increasing number of restoration initiatives around the world promoting tree planting and consequently increasing forest cover. Nevertheless, a comprehensive overview of the effects of tree planting on infiltration and the factors controlling these effects is lacking. Here, we conducted a systematic review of scientific literature reporting infiltration measures in restored forests in the tropics. We found eleven studies representing 67 data comparisons in eight countries. Overall results indicate that infiltration is likely to increase after tree planting in forest restoration. Infiltration recovered quickly when agriculture was the prior land-use, whereas recovery was slower when trees were planted into pastures and bare soils. There was a trend in restored forests with soils having >30% clay to exhibit greater increases in infiltration, contrasting with the smaller increases for sandy soils (<30% clay). Restored forests after 10 years evidenced similar infiltration values than the pre-disturbance soil conditions. Our findings emphasize the need to monitor water infiltration in restored forests under different soil conditions and over time. Finally, we identified six knowledge gaps requiring future research efforts, that aim to improve our understanding of when and why forest restoration may promote recovery of infiltration in tropical soils.