Members Only: SER/ATBC - The Role of Tropical Secondary Forests in Conservation and Restoration
Monday, December 18, 2017
Posted by: Rebecca Shoer
The Role of Tropical Secondary Forests in Conservation and Restoration from Society for Ecol. Restoration on Vimeo.
Secondary forest regrowth following agricultural land use represents a major feature of human modified landscapes across the tropics. International interest is growing regarding the importance of secondary forests for biodiversity conservation, for large-scale reforestation programs, and for the role of these forests in mitigating effects of global climate change. In this webinar, researchers from different disciplines of social and natural science will discuss the importance of second-growth forests for conserving and restoring biodiversity, and recovering ecosystem functions and services. This webinar will address key questions about the ecology, governance, landscape conditions, and social drivers of secondary tropical forests and the role these forests can play for conservation and restoration in the Anthropocene. The panel will include researchers from different disciplines of natural and social sciences that will discuss these aspects and pinpoint guidelines for future research and policies for conserving biodiversity and to restore degraded lands in human modified landscapes across the world's tropics.
Selected questions from the Q & A
What are the key elements to engage forest owner to productive restoration of secondary forest?
With silvo-pastures the value added by increased numbers of trees in pastures provided some incentives to allow for the growth of secondary forest trees. A PES program for the carbon sequestered in the silvo patterns would add at current prices an additional $15 per year per hectare in income.
How does active restoration work? Are trees planted only once? In that case, we would get one cohort of forest, which would not seem very different than passive succession. If trees are planted multiple times, this seems like a situation more close to passive succession, and potentially more beneficial for biodiversity.
Most trees are planted at once but later there is enrichment planting. It is often important to plant trees to reduce week cover as quickly as possible.
Interesting talk and very relevant to the prevalent cattle ranching landscapes in Latin America. How did the trees spontaneously establish themselves in such hostile landscapes, such as active cattle pastures? Was there no use of fire, herbicides, no active grazing? In Central America, it is very difficult to promote natural regeneration in actively managed cattle pastures, mainly because the of the pathogenic disturbance regimes mentioned above.
A very good question! First of all, there is no use of fire in this zone by landowners. It is just too humid for fires to burn. Cattle only graze a pasture once every 10-12 months, after the pasture has become fully grown. Fences are not used to separate pastures. Rather cows are tethered and pulled in a line into expanses of mature pasture once or twice daily. During these ten month – one year intervals between the grazing of an area the seedlings sprout spontaneously. After cows graze an area, the person tending the cows will come through this area and cut out most seedlings, so that they do not suppress the regrowth of the pastures. If the seedlings are of a commercially valuable tree, then person doing the cutting will allow the seedlings to grow. Over time the growth of the seedlings creates a silvo-pasture, with clear increments in plant and avian biodiversity.
All presenters have presented research on secondary forests in the Neotropics only. Can the results and recommendations of these studies be generalized to the Paleotropics which are very different both ecologically and socio-economically? Or in other words, is the knowledge gap on secondary forests, particularly in the Congo basin, a problem for conservation?
A very good point and question. The relative absence of pastures in the wetter places in the Congo basin would make silvo-pasture focused projects inappropriate. We need much more data to be able to answer this question. Much of our knowledge is based on long-term plot studies as well as replicated chronosequence data. Very litle data are available outside of Latin America. We hope this will change!