Restoration of dry tropical forests in Central America: A review of pattern and process

Restoration of dry tropical forests in Central America: A review of pattern and process

Background

Much information on restoration and management exists for wet tropical forests of Central America but comparatively little work has been done in the dry forests of this region. Such information is critical for reforestation efforts that are now occurring throughout Central America. This paper describes processes of degradation due to land use and provides a conceptual framework for the restoration of dry tropical forest, of which less than 2% remains intact.

Goals & methods

Main attempts at reforestation of dry tropical forest have been by protecting the land from fire and cattle; supplementing natural regrowth with enrichment planting; and through use of tree plantations. Experimental studies have demonstrated the ability of these lands to grow back to forests because of native species ability to sprout after cutting, and the capacity of remnant trees in field and riparian zones to provide seeds and to moderate edge environment for seed germination and seedling establishment.

However, research also shows that on sites with long histories of land clearance, species diversity will remain low with functional groups missing unless some active management occurs. Under-planting with late-successional native tree species can add structure and diversity; enrichment planting with large-fruited shade-intolerant species can initiate new islands of more diverse regeneration beneath their canopies; and plantings of fast-growing, nitrogen-fixing trees that provide light canopy shade can moderate the environment below, promoting regeneration establishment of late-successional species.

Conclusions & takeaways

Plantations are the only option for lands that have lost almost all remnants of native forest, and where soils and vegetation have changed to new states of structure and function. Conversion of pastures to tree plantations that can facilitate natural regeneration beneath them is appropriate when pastures are prone to fire and/or lack immediate seed sources nearby. After the grasses have been shaded out, natural recruitment can occur slowly over a 10–15 year period. Under-planting of shade-tolerant late-successional species can supplement species composition and structure.

Reference: 

Griscom HP, Ashton MS. Restoration of dry tropical forests in Central America: A review of pattern and process. Forest Ecology and Management. 2011;261:1564–1579. doi:10.1016/j.foreco.2010.08.027.

Affiliation: 

  • Department of Biology, James Madison University, Harrisonburg, VA, United States
  • School of Forestry and Environmental Studies, Yale University, New Haven, CT, United States