Tree species assembly in regenerating seasonally dry mixed deciduous forests of Lao PDR

Forest cover in Lao PDR (Laos), like many tropical countries, has decreased dramatically over the past century. As a response, the Laos Government has set targets to return forest cover to 1940’s levels by the year 2020. The majority of this reforestation will occur through the establishment of plantations, and through protecting natural regeneration. Much of the area to be reforested in Laos was once covered by seasonally dry tropical forests. Despite this forest type being one of the most threatened terrestrial ecosystems worldwide, only a small proportion of the literature on tropical forest restoration is focussed upon them. It has been argued that the natural regeneration attributes of these forests can differ substantially from those of wetter evergreen forests and therefore application of restoration techniques adapted for wet forest systems may be inappropriate. This research investigates patterns of recolonisation and tree species assembly in regenerating seasonally dry mixed deciduous forest by comparing functional attribute associations under different regeneration conditions. These include different aged fallow land, remnant forest patches, and species recruitment underneath 10-year-old monoculture plantations. Identified patterns of functional attributes, such as dispersal syndrome, seed size, and variation in specific leaf area, are used to make generalisations about the types of species that are better able to recolonise degraded areas under the current restoration management techniques. The primary field site is a multi-use landscape consisting of intensive paddy areas around villages, slash and burn dry land rice production and fallow areas, small tree plantations, and remnant forest patches.