tailieunhanh - Biomass and Remote Sensing of Biomass Part 4

Tham khảo tài liệu 'biomass and remote sensing of biomass part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Invasive Plant Species and Biomass Production in Savannas 51 soil. These are some of traits found in invasive species such as Prosopis juliflora Pasiecznik 2001 . Furthermore many of the woody species found in the savanna have ligno-tubers and deep roots enhancing the root shoot ratio while tropical grasses generally have a high capacity to accumulate below-ground carbon Scholes Hall 1996 . Losses mainly through burning and soil erosion also determine the amount of carbon sequestered. As discussed above fire is an integral driver and determinant of tropical savanna function and structure with large areas seasonally burnt resulting in an efflux of carbon in the range of Gt C year-1 or 42 of global burned phytomass and as high as 5-8 Gt C year-1 if other losses such as management for grazing and land-use change are taken into account Hall Scurlock 1991 may influence the regional and possibly global energy. Plant traits that reduce carbon loss include fire resistance manifested by thick bark dense wood and high lignin concentration others include fire resilience traits such as fire tolerant seeds and resprouting. From the foregoing invasive species will significantly alter carbon pools depending on whether they have large enough effects on flux variables such as above-ground net primary production and litter decomposition fire regimes resources such as water and nutrients this will depend on their traits of the invader. By alteration of the components of the Carbon C and nitrogen N cycles which are fundamental ecosystem functioning and processes invasive plants influence sequestration. Do introduced plant species that turn invasive have traits that augment carbon sequestration Many studies have shown that ecosystem net primary production NPP to have increased and C and N stocks to be higher in the invaded ecosystems relative to the native ecosystems Ehrenfeld et al. 2001 . However due to the wide range of effects of invasive plants on C and N processes and .