The Tale of Western Chitwan Community Forests: Historical Vegetation Dynamics and the Challenges with the Invasion of Mikania micrantha
- Author(s): Dai, Jie;
- Advisor(s): An, Li;
- Roberts, Dar A
- et al.
This dissertation addresses the historical vegetation dynamics in community forests, their novel challenges introduced by the invasion of an exotic creeping vine, and simulations of large-scale intervention practices in western Chitwan, Nepal. Situated in the Chitwan National Park buffer zone, these community forests stand as the frontiers of human-environment interactions, nurturing both endangered large mammals such as Bengal tigers (Panthera tigris tigris) and great one-horned rhinos (Rhinoceros unicornis), as well as local forest users. For the past three decades, especially after their establishments in the mid-1990s, these forests have been greening up. In addition to community forest management, some of the green-up signals may be affected by the invasion of a notorious understory creeping vine, Mikania micrantha. Integrating remote sensing techniques (Multiple Endmember Spectral Mixture Analysis) and species distribution modeling (Maximum Entropy Modeling Framework), we developed a pixel-based presence probability map for the invasive plant in the study area. By the year 2015, the invasion was most prominent in riverine forests and riparian grasslands. To combat the spread of M. micrantha in the study area, we tested a cost-effective bag-and-bury treatment and developed a socio-ecological data informed agent-based model to project local household participation in an intervention program as well as M. micrantha’s extent under the intervention practices. Both social survey and simulation results indicated that about 40% of the households in the study area can contribute at least ten full days of labor per year to the modified intervention treatments, and M. micrantha can be eliminated from the community forests after three years of intensive intervention, although routine patrolling should be adopted to eradicate potential future invasion from the neighboring national park. This dissertation incorporated a coupled human and natural systems (CHANS) approach and integrated both social and ecological factors. The results can provide significant insights for not only local conservation practices, but also broader sustainable managements and development goals.