Most threats that have been detected concern ecosystems, especially forests and to some extent wetlands. The degradation of ecosystems also affects species and genetic diversity. Current trends in deforestation particularly threaten diversity of forest dependent flora and fauna. Activities such as conversion of forest to agricultural land lead to permanent losses or changes in availability of non-wood forest products. NWFP encounters other threats; these are essentially caused by poaching, introduced species and pollution (Chidumayo and Marjokorpi, 1997).
Deforestation is caused by excessive cuttings in illegal coupes and commercial harvesting as well as conversion of forests into agricultural land by encroachment of forest reserves and other land categories. Depletion of certain treespecies due to selective cutting in commercial harvesting leads to local extinction of species. This in turn results in loss of all NWFP that are associated with such tree species. The opening up of the tree canopy also leads to increased grass growth which increases the risk for severe late forest fires.
There is therefore, need to have sufficient information on the growing stock, quality and regeneration status of forests in order to make planning of sustainable harvesting of NWFP possible.
The timing and frequency of fires determine the effect of fire on the ecosystem. Frequent late fires prevent regeneration of fire tender species and thus change the species composition resulting in an open type of chipya vegetation. Late forest fires also destroy millions of other fauna species, affecting the resource base permanently
Poaching is one of the causes of game population's depletion in Game Management Areas (GMA) and National Parks. Some wildlife estates have been decimated by poaching activities as a result of poor funding for the sustainable management and protection of wildlife resources. For example, Mansa GMA, Lusenga National Park, Mweru-wa-ntipa National Park, have been decimated and wildlife populations are depleted (Kapungwe, 1996)
Some introduced species have become invasive and pose a threat to ecosystems and indigenous flora. Such are known as obnoxious weeds under the Obnoxious Weeds Act, e.g. Lantana camara and the aquatic fern, Kariba weed (Salvina molesta). These introduced species thrive vigorously and usually suppress regeneration of certain natural species. Salvinia molesta has led to the death and depletion of certain forms of aquatic life including edible fish and reptiles.
There is, however, little documentation on the effects of mining and industrial air, soil and water pollution on NWFP. Nevertheless there are a few areas on the Copperbelt where plants have died due to air and/or soil pollution from copper mines. Other sources of pollution are chemical contamination from waste disposal sites and from use of agro-chemicals. Deterioration in water quality has been detected in the Kafue river whose origin is in the heavily industrialised Copperbelt area (Chidumayo and Marjokorpi, 1997).
