In Laos, there are extensive shifting cultivation areas and regrowth forests spontaneously established on fallow lands. The aims of the study were to conduct a comparative study of old-growth and regrowth forests in terms of structure, woody species diversity and composition as well as to investigate the potential role of regrowth forests in the conservation and restoration of degraded forest lands in Laos and the tropics in general. Systematic plot sampling was used to survey the floristic diversity, species composition and structure of old-growth and regrowth forests. Concentric circular plots with an area of 200 m² and 500 m² were laid on line transects. A total of 24 plots were sampled from two sites. In comparison to regrowth forests, old-growth forests had higher structural heterogeneity because of higher canopy height variations, vertical stratification, and tree sizes and their variations. Species richness and diversity indices values were similar, but abundance and species composition were significantly different between old-growth and regrowth forests. It appears that species richness recovers first followed by forest structure and species composition. Regrowth forests are important for in situ conservation of tropical biodiversity and they can also serve as a conduit for the restoration of degraded lands and forests. Regrowth forests provide habitats, serve as buffer zones around the fragmented old-growth forests, function as source of propagules, and enhance landscape connectivity. Utilization of regrowth forests for restoration purposes is comparatively inexpensive. Regrowth forests should be given the due considerations in the national forest conservation and restoration policy of Laos.

Ecological compensation, which is widely applied, is presumed to be an important mechanism to address environmental degradation that commonly occurs due to activities related to development projects and resource use. The objectives of this review are to investigate synergies and trade-offs between biodiversity and carbon offset, the challenges in their implementation, and the potential of biodiversity and/or carbon offsets to be used as a proxy for other ecosystem functions in the implementation of ecological compensation. In comparison to carbon offsets, the implementation of biodiversity offsets are more challenging due to difficulties in biodiversity measurement, determining ecological equivalence, the relatively longer time taken, the higher level of uncertainty, the uniqueness of ecosystems, and the irreversibility of species loss. Generally, there is a positive relationship between biodiversity and carbon stocks; however, there are also cases where there are no clear or even negative relationships between biodiversity and carbon stocks. Ecosystem functions are directly or indirectly affected by environmental degradation, and ecological compensation measures usually compensate for only a few components of the ecosystem functions. Since biodiversity is interconnected and underpins ecosystem functions, it has the potential to be used solely or as one of the proxies. However, we recommend developing a sound methodology to rank the important ecosystem functions and identify the few ecosystem functions, which can be used as proxies to indicate the achievement of ecological compensation goals.