PART II SELECTED CURRENT ISSUES IN THE FOREST SECTOR low-intensity selective logging could be one Perhaps even worse are invasive alien species component of plans to conserve primates. On the that are introduced unintentionally, such as disease other hand, high-intensity logging, typical of most organisms that can devastate an entire tree spec logging operations in the tropics, is incompatible (e.g. Dutch elm disease and chestnut blight in with primate conservation( Chapman et aL., 2000). North America)or pests that can have a major effect on native forests or plantations(e.g. gypsy Invasive alien species moths and long-horned beetles). The economic As the global movement of people and products impact of such species amounts to several hundred expands, so does the movement of plant and billion dollars per year(Perrings, Williamson and animal species from one part of the world to DaImazzone, 2000), much of it in forested another. When a species is introduced into a new ecosystems, even within well-protected national habitat-for example, oil palm from Africa into parks. The 1951 International Plant Protection Indonesia, Eucalyptus species from Australia into Convention was established to address some of California, and rubber from Brazil into Malaysia- these issues, and new international programmes the alien species typically requires human are now addressing the most serious problems intervention to survive and reproduce. Indeed, The World Conservation Union(IUCN)has many of the most popular species of tree used for developed a global strategy ( McNeely et al., 2001), groforestry are alien or non-native and prosper in and best practices for prevention and management their new environments partly because they no have been identified(Wittenberg and Cock, 2001) longer face the same competitors, predators and However, as global trade grows, so does the threat pests as in their native environment. Such alien from devastating invasive species of insect and species are economically very important and athogen. They could fundamentally alter natural enhance the production of various forest forests and wipe out tree plantations, the latter commodities in many parts of the world being especially vulnerable because of their lower In some cases, however, species introduced species diversity Efforts related to both intentionally become established in the wild and conservation of biological diversity and sustainable spread at the expense of native species, affecting forest management need to recognize clearly and entire ecosystems. Notorious examples of suc address the issue of invasive alien species invasion by alien woody species inc introduction of kudzu( Pueraria lobata)from Japan Climate change and China into the United States, where it now Forests are often highly sensitive to climate, infests over 2 million hectares; the ecological judging by the past distribution of forest types takeover of the Polynesian island of Tahiti by during periods with different climates and by the Miconia calvescens; the spread of various species of vegetation bands on mountains. While the Northern Hemisphere pine and Australian acacia Intergovernmental Panel on Climate Change in southern Africa; and the invasion of Floridas(IPCC)and associated national research Everglades National Park by Melaleuca species programmes are generating valuable new from South America. Of the 2 000 or so species information, forecasts of the potential impact of that are used in agroforestry, perhaps as many as climate change on forests remain somewhat 10 percent are invasive. Although only about speculative. Some contend that the most significant rcent are highly invasive, they include threats are drying trends, changes in rainfall opular species such as Casuarina glauca, Leucaena patterns, changes in fire regimes and changes in Great care is required to ensure that such spedes species distribution and composition. Other ges in nd Pinus radiata(ri ality, which would in turn lead to chang serve the economic purposes for which they were suggest that forests may be equally affected by the introduced and do not escape to cause indirect effects of climate on soil properties or on unanticipated negative effects on native reproduction. In the final analysis, the most ecosystem important factor may well be the impact of climate89 SECTOR FOREST THE IN ISSUES CURRENT SELECTED II PART one be could logging selective intensity-low the On. primates conserve to plans of component most of typical, logging intensity-high, hand other incompatible is, tropics the in operations logging .(2000., al et Chapman (conservation primate with species alien Invasive products and people of movement global the As and plant of movement the does so, expands to world the of part one from species animal new a into introduced is species a When. another into Africa from palm oil, example for – habitat into Australia from species Eucalyptus, Indonesia – Malaysia into Brazil from rubber and, California human requires typically species alien the ,Indeed. reproduce and survive to intervention for used tree of species popular most the of many in prosper and native-non or alien are agroforestry no they because partly environments new their and predators, competitors same the face longer alien Such. environment native their in as pests and important very economically are species forest various of production the enhance .world the of parts many in commodities introduced species, however, cases some In and wild the in established become intentionally affecting, species native of expense the at spread such of examples Notorious. ecosystems entire the include species woody alien by invasion Japan from) lobata Pueraria (kudzu of introduction now it where, States United the into China and ecological the; hectares million 2 over infests by Tahiti of island Polynesian the of takeover of species various of spread the; calvescens Miconia acacia Australian and pine Hemisphere Northern s’Florida of invasion the and; Africa southern in species Melaleuca by Park National Everglades species so or 000 2 the Of. America South from as many as perhaps, agroforestry in used are that about only Although. invasive are percent 10 include they, invasive highly are percent 1 Leucaena, glauca Casuarina as such species popular .(1999, Richardson (radiata Pinus and leucocephala species such that ensure to required is care Great were they which for purposes economic the serve cause to escape not do and introduced native on effects negative unanticipated .ecosystems species alien invasive are worse even Perhaps disease as such, unintentionally introduced are that species tree entire an devastate can that organisms in blight chestnut and disease elm Dutch. g.e( major a have can that pests or) America North gypsy. g.e (plantations or forests native on effect economic The). beetles horned-long and moths hundred several to amounts species such of impact and Williamson, Perrings (year per dollars billion forested in it of much), 2000, Dalmazzone national protected-well within even, ecosystems Protection Plant International 1951 The. parks of some address to established was Convention programmes international new and, issues these .problems serious most the addressing now are has) IUCN (Union Conservation World The ,(2001., al et McNeely (strategy global a developed management and prevention for practices best and .(2001, Cock and Wittenberg (identified been have threat the does so, grows trade global as, However and insect of species invasive devastating from natural alter fundamentally could They. pathogen latter the, plantations tree out wipe and forests lower their of because vulnerable especially being both to related Efforts. diversity species sustainable and diversity biological of conservation and clearly recognize to need management forest .species alien invasive of issue the address change Climate ,climate to sensitive highly often are Forests types forest of distribution past the by judging the by and climates different with periods during the While. mountains on bands vegetation Change Climate on Panel Intergovernmental research national associated and) IPCC( new valuable generating are programmes of impact potential the of forecasts, information somewhat remain forests on change climate significant most the that contend Some. speculative rainfall in changes, trends drying are threats in changes and regimes fire in changes, patterns in changes to lead turn in would which, seasonality Others. composition and distribution species the by affected equally be may forests that suggest on or properties soil on climate of effects indirect most the, analysis final the In. reproduction climate of impact the be well may factor important