IAS_2.5.2.1_164

A worldwide review of invasive alien species in tropical and subtropical dry and humid forests has never been done, and most data available to date are at the country-level rather than at the level of biogeographic regions such as units of analysis. Of the countries with major areas covered by tropical and subtropical dry and humid forests, data are available mostly for South America, some parts of Mesoamerica and the Caribbean, and for South Asia, while data is scarce for tropical and subtropical dry and humid forests in Africa.
Biological invasions in tropical and subtropical dry and humid forests have been less studied than most other terrestrial ecosystems. This lack of data is, in part, explained by the lower numbers of invasive alien species recorded for tropical forests compared to other ecosystems. However, given the growing anthropogenic pressure over these regions, it is likely that biological invasions will increase in the next decades in tropical and subtropical forests, especially in regions with high intensity of land use change. Most reports available for tropical and subtropical dry and humid forests are for plant invasions, and there is very limited data on animal invasions except for a few well-studied species, such as Herpestes javanicus auropunctatus (small Indian mongoose) and Boiga irregularis (brown tree snake). For most regions with these forests, lists of established plant species are available (Pyšek, Pergl, et al., 2017; van Kleunen et al., 2019), but these data provide very little insight into the actual situation of biological invasions in tropical and subtropical dry and humid forests (e.g., spread and impacts).
As a general trend in Asia, the cumulative number of invasive plants is known to increase exponentially over years (e.g., in China: H. Xu et al., 2012). However, information on trends and status of invasive alien plants in tropical and subtropical forests in Asia are largely unavailable. Attempts are currently being made by some countries to prepare national inventories for invasive alien plants (e.g., Dorjee et al., 2020; Mukul et al., 2020), though these lists do not appear to include information on the habitats in which the alien species occur.