Comprehensive data on the amount and types of indigenous forest in Tonga are unavailable. Some data are provided by Wiser et al. (1999) for Tongatapu and nearby islands and by Whistler (1992) and references cited. Remaining indigenous forest cover has been variously estimated at between 5.5% (FRA 2005) and 11.6% (Desloges 1994) of land in the country, with much of this confined to inaccessible steep (Figure 1) or remote areas, uninhabited islands, coastal strips, swamps and mangroves (Thistlethwaite et al. 1993). The variability in these figures probably results from differences in defining forest. According to FRA 2005 data, Tonga has the lowest percentage of forest cover in all Oceania, where the average is 23.3%. Recent data from the Ministry of Land. Figure 1. Indigenous forest in the Mt Talau National Park on Vava'u (2008) Forest clearing has reduced biodiversity, promoted soil erosion and reduced soil fertility. Coastal forested strips have narrowed and mangrove removal has accelerated coastal erosion. The forest fragments, however, still contain valuable biodiversity worth protecting. Much of this information is anecdotal. There are no reliable data on the extent and rate of recent deforestation, although there is no doubt that it is occurring. Deforestation is most pronounced on the main island of Tongatapu, where the area of remaining forest is less than 5% (Table 1). In the past, traditional low-intensity shifting agriculture had long fallow periods. However, increased population pressure over recent decades has shortened or eliminated fallow periods, leading to loss of soil fertility and the necessity to clear more forest to maintain agricultural productivity. The introduction of the export squash industry in the