Reforestation efforts to date have relied largely on a comparatively small number of fast-growing, exotic species (from an even smaller number of genera).
These species were often regarded as "miracle trees" when they were first introduced because of their ability to grow rapidly, particularly in experimental conditions. These so-called miracle species included Acacia auriculiformis, Acacia crassicarpa, Acacia mangium, Casuarina equisetifolia, Pinus caribaea, Eucalyptus camaldulensis, Eucalyptus deglupta, Eucalyptus tereticornis, Gmelina arborea, Leucaena leucocephala and Paraserianthes falcataria (formerly Albizia falcataria).
Hybrids between some of these have also been developed. But all of these species have site preferences and, not surprisingly, many have not always performed as well as expected when more widely planted. This is not to say that they do not have a role to play. Rather, it is wrong to assume that there are "miracle" species that will suit all site conditions and fulfill the needs of all stakeholders interested in reforestation within a region as large and as diverse as Asia and the Pacific.
Except for South Asia, most previous reforestation was carried out in large monoculture plantations for industrial purposes. In addition, many of these plantations were established to produce pulpwood and were grown in rotations of only 10 years or less (Nambiar and Brown 1997, Cossalter and Pye Smith 2003).
Monoculture plantations of fast-growing exotic species such as Eucalyptus... these are attractive to industrial timber growers because of their potentially high productivity. They produce a limited range of goods and should not be seen as the only means by which degraded lands are reforested.
Such reforestation had been promoted by most countries in the region in the expectation that it would help generate a renewable resource, provide employment in rural areas and contribute towards national income. In many cases direct and indirect subsidies were provided. These included access to cheap land, reductions in taxation and, sometimes, financial assistance of various kinds. In most cases, this support was directed largely at large corporations and industry groups (Enters et al. 2004).
All this has led to a process of landscape simplification that has now been underway across the region for several decades, resulting in some of the richest and most diverse forests on earth being replaced by simple agricultural or plantation forest landscapes.
The trend towards simplification has also been accompanied by considerable uncertainty. This includes uncertainty over the sustainability of some of the agriculture presently established on cleared forest lands (with an increasing extent of abandoned agricultural land demonstrating just how problematic some of the original agricultural operations have been).
There is also growing uncertainty in many tropical areas over hill slope stability, watershed protection and the future availability of adequate amounts of clean, high-quality water.
