Portal de Periódicos da CAPES

Tropical grassy biomes: misunderstood, neglected, and under threat

2014; Elsevier BV; Volume: 29; Issue: 4 Linguagem: Inglês

10.1016/j.tree.2014.02.004

1872-8383

Catherine L. Parr, Caroline E. R. Lehmann, William J. Bond, William A. Hoffmann, Alan N. Andersen,

Land Use and Ecosystem Services

•Tropical grassy biomes are extensive and critical to human livelihoods. •The definition of these grassy systems is inconsistent and misleading. •We discuss novel threats linked to problems with biome definition. •The assumption that ‘more trees are better’ does not hold for tropical grassy biomes. Tropical grassy biomes (TGBs) are globally extensive, provide critical ecosystem services, and influence the earth–atmosphere system. Yet, globally applied biome definitions ignore vegetation characteristics that are critical to their functioning and evolutionary history. Hence, TGB identification is inconsistent and misinterprets the ecological processes governing vegetation structure, with cascading negative consequences for biodiversity. Here, we discuss threats linked to the definition of TGB, the Clean Development Mechanism (CDM) and Reducing Emissions from Deforestation and Forest Degradation schemes (REDD+), and enhanced atmospheric CO2, which may facilitate future state shifts. TGB degradation is insidious and less visible than in forested biomes. With human reliance on TGBs and their propensity for woody change, ecology and evolutionary history are fundamental to not only the identification of TGBs, but also their management for future persistence. Tropical grassy biomes (TGBs) are globally extensive, provide critical ecosystem services, and influence the earth–atmosphere system. Yet, globally applied biome definitions ignore vegetation characteristics that are critical to their functioning and evolutionary history. Hence, TGB identification is inconsistent and misinterprets the ecological processes governing vegetation structure, with cascading negative consequences for biodiversity. Here, we discuss threats linked to the definition of TGB, the Clean Development Mechanism (CDM) and Reducing Emissions from Deforestation and Forest Degradation schemes (REDD+), and enhanced atmospheric CO2, which may facilitate future state shifts. TGB degradation is insidious and less visible than in forested biomes. With human reliance on TGBs and their propensity for woody change, ecology and evolutionary history are fundamental to not only the identification of TGBs, but also their management for future persistence. the type of carbon assimilation performed by most plants. This is the most efficient form of photosynthesis under moderate to cool temperatures, high CO2 concentrations, and high water availability. a form of photosynthesis that is evolutionarily derived from C3 photosynthesis, but which includes an additional mechanism for actively transporting CO2 into specialized cells where photosynthesis occurs. This makes C4 plants particularly tolerant of high temperatures, low water availability, and/or low CO2 concentration. C4 photosynthesis is most common among grasses, including maize, millet, and sorghum. the quantity of carbon contained in a ‘pool’, meaning a reservoir that has the capacity to accumulate or release carbon. It refers to both live and dead material and is usually separated in to the amount of carbon stored above ground (e.g., trees, grasses, dead wood, and litter) and that stored below ground (e.g., in soils, roots, and peat). tropical moist savanna in Brazil, accounting for >20% of the land area of the country; very varied in form from dense grassland to almost closed canopied savanna; also includes wetland areas. a carbon-trading system established by the Kyoto Protocol designed to allow a country with an emission-reduction commitment to implement projects in developing countries. Such projects can earn saleable, certified emission reduction credits, each equivalent to 1 t of CO2; these can count towards meeting Kyoto targets. Under CDM, the only eligible forestry projects are afforestation and reforestation projects. a herbaceous flowering plant, other than a graminoid (grasses, sedges, and rushes). plant with underground storage organs (e.g., bulbs, tubers, or corms), which provide reserves of carbohydrates, nutrients, and water. microscopic silica bodies that form in the cells of many kinds of plant. They can be used to identify plant remains in archaeological and palaeoecological work.