[Table of Contents]

Sustainability of Forests


Plantations and Rehabilitation
of Degraded Land


Plantation forestry, especially on degraded or low-potential sites, is a major focus of research by CIFOR because of the need to meet the world’s huge appetite for lumber, pulp and other wood products. Much of this work includes efforts to optimise the productivity of plantation forests.

The challenge for foresters, scientists and industry is to develop planted forests that are economically viable as well as biologically sustainable. This is already being achieved in many industrialised countries. Yet plantation forestry is still relatively new in many tropical countries, and little is known about local conditions and problems that may limit yields – poor water and nutrient levels in the soil, erosion, genetic stock variation and improper site preparation, for example.

Under the direction of Dr. Christian Cossalter, an expert on reforestation of marginal lands, CIFOR is engaged in a number of research studies around the world designed to yield information that will improve soil fertility and boost productivity of tree plantations over successive generations.

In 1998, field experiments continued at 16 plots in seven countries – Australia, Brazil, China, Congo, India, Indonesia and South Africa – in a project to determine the best methods for plantation harvesting in tropical countries under a wide range of ecological conditions. The results will help site managers select the best management strategies to correct productivity problems at the individual sites, and should be relevant as well to plantation forestry in general.

Among the sites under study are low-performing eucalyptus plantations in China and India. Planted eucalyptus forests are one of the major sources of wood and pulp for both domestic and international demand. But yields at the experimental sites in China and India are well below average for the species. Researchers are testing a variety of treatments they hope will remedy the problem.

Meanwhile, similar experiments launched in 1998 provide the basis for research to develop "criteria and indicators" suitable for guiding management of plantations to maintain or increase productivity. Another tool being developed to aid plantation management is a promising approach that combines geographical information systems (GIS) and multi-agent systems (MAS). Eventually it should enable forest managers to build spatial models of plantations to examine interactions of plantations with other natural resources and with local inhabitants, thereby facilitating decisions related to landscape management.

Although forest plantations are well-delineated areas, they are nonetheless part of larger landscapes. This raises important questions about what impacts plantations may have on broader ecosystems. How, for example, does plantation agroforestry affect biodiversity? Do plantations near protected areas pose a threat to the native flora and fauna by facilitating the introduction of generalist or exotic species? CIFOR is expanding its work on plantations to address questions such as these.

Rehabilitation of forest land that has been degraded offers potential commercial value as well as important environmental benefits. Regeneration requires addressing problems such as loss of soil fertility, the effects of erosion and disturbance to hydrological balance and other ecological functions. Solutions include a variety of practices such as accelerating natural regeneration, enrichment planting, altering rotation cycles, cultivating fast-growing species, using improved genetic stock, reducing the impacts of logging and establishing mixed plantations with fast growing and shade tolerant species.

CIFOR research on degraded lands spans the globe, encompassing a range of forest types. Japan has been a major funder of this programme, which is coordinated by Dr. Shigeo Kobayashi.

One focus of research is silvicultural techniques for improving degraded forest lands. A joint study with Kasetsart University in Thailand, for example, is evaluating the ecological impacts of teak plantation thinning at various patterns and intensities, and the effects on intercropping with plants such as coffee. In another plantation study, experiments got underway in 1998 at two 7-year-old eucalyptus plantations in Sao Paulo State, Brazil, that are owned by paper mills. Planned in conjunction with Brazil’s EMBRAPA/CNPF, the study will evaluate how the impacts of soil compaction from harvesting and tilling methods affects site productivity. The findings will have broad implications, because eucalyptus forests make up nearly 40 percent of all tree plantations in Brazil, with about 1 million acres in Sao Paulo State alone.

In a major partnership with China, CIFOR scientists are studying socioeconomic approaches that could help support widespread efforts to reclaim degraded lands. Degraded lands in mountainous and hilly areas account for more than 60 percent of China’s total land area, and there is a dire need to encourage productive use of this land, especially by small-scale farmers. Tree planting is a highly favored solution, but there is concern about the sustainability of tree planting on such lands. The Chinese Academy of Forestry has produced a number of technological solutions, but a major problem is how to apply these technologies at a wide scale and in ways that are appropriate for selected areas.

Unfortunately, forestry research in China and other countries is often hampered by poor data. Available information about forest resources may be inconsistent and uneven in quality, and methods commonly used to compile such material can lead to inexact interpretations. In 1998, CIFOR scientists continued their collaboration with several institutions in China and Indonesia to improve systems of collecting forest data, thereby facilitating more authoritative analysis. Following a review of statistical data from forestry agencies in the two countries, they began synthesising and analysing the results and formulating recommendations in preparation for a related workshop that will be held in Bejing in May 1999.