Responses of Transplanted Native Tree Species to Invasive Alien Grass Removals in an Abandoned Cattle Pasture in the Lacandon Region, Mexico

background

This study measures the response of 16 native tree species to manual invasive grass removal treatments, for cost-effective regeneration of tropical forest on abandoned cattle pasture in the Lacandon region of Chiapas, southeast Mexico.

Research Goals & Methods

Tree species selected for use in the study were considered of ethnobotanical interest or commercial use, to provide ecosystem services and forest goods, and grouped by early-successional, mid-successional, and late-successional species in order to incorporate a diversity of "functional groups" to either promote fast soil coverage and immedate conditions improvement, or long-term development and self-maintenance of forest structure, facing competition with the grass Cynodon plectostachyus. By measuring the performance of seedlings during first 18 months after planting, the study indicates some species' high response to fewer grass removal treatments, while others required further grass removal in order to improve survivorship and aboveground biomass increase.

Conclusions & Takeaways

Grass removals generally improved the sapling performance of a range of native tropical tree species and greatly reduced C. plectostachyus dominance even if it did not lead to eradication. The authors include a risk analysis, indicating the relatively low risk and high success of utilizing early-successional species to overtop C. plectostachyus, but they emphasize the need to include late-successional species in restoration plantings for long-term ecosystem functioning. The study also recorded operational costs, materials, and labor requirements for each of the three treatment levels applied, to determine cost-effectiveness of aided regeneration given limitations on management funds.