執行成果摘要
This study analyzes the long-term meteorological and hydrological monitoring data in Fushan and Lianhuachi areas to understand the frequency and pattern of extreme climate in forests. The dry and wet seasons and heavy rainfall events are also discussed since they would cause changes in flow characteristics, flow components, nutrient concentrations, and budget. Hence, a scenario projection would be proposed after the global temperature is raised. Research results are helpful for future environmental change assessment, water resources scheduling, and mountain flood control, and serve as an important reference basis for forest management and disaster prevention management. The flow measuring weir is an important test facility for hydrological experiments. Because the great difference in discharge in the Fushan Hapen catchment area, how to avoid the water sample monitoring instruments being washed away by extreme runoff is concerned. The stilling pond is a relatively safe place to set up automated monitoring instruments. However, it is a quiet different stream environment in the flow measuring weir. Whether the hydrological data measured inside the weir is representative or not, needs to monitor for a period of time to understand. The relationship of water quality changes between in the upstream and the flow measuring weir, can be used as a reference for calibrating monitoring data. And it will improve our understanding of the flow measuring weir in influencing stream environment and downstream water quality. In recent years, extreme weather events often lead to sediment disasters and cause road interruption on the roads outside Fushan Experimental Forest. Because this road is the only way for colleagues to go to work and visitors to the Botanical Garden, in order to reduce the risk of the preservation object being exposed to the potential disaster environment, it is necessary to specifically investigate the potential of sediment disasters on the road, provide information on the road sections with potential collapse risks, develop and deal with countermeasures and plan appropriate disaster prevention measures. Affected by extreme weather in recent years, sediment disasters caused by torrential rain frequently occur in forest watersheds. Sediment disasters such as landslides and debris flow are a major problem in forest management. In order to assess the risk of sediment disasters in forest watersheds, a risk assessment model can be established based on relevant environmental indicators. Screening hot spot areas for important preservation objects, and formulating corresponding management strategies for the reference by relevant departments in the management of forest watersheds. Fuel load and temporal variation of dead fuel moisture of dominant species in mountane and subalpine area are crucial for asessing the area required fuel management to reduce hazard. We sampled the fuel load and dead fuel moisture of the dominant species of Yushan cane, Alpine Silver Grass, Taiwan red pine, and Taiwan Hemlock. We also built the prediction model between the dead fuel moisture and 10-hour fuel. The purpose of the work project of studying on the selection of artificial restoration tree species and effectiveness monitoring in the collapsed area is to speed the succession of landslide by artificial restoration. Before artificial restoration, we should first understand the succession stage, dominant trees and seedling composition, whether the seed source is enough, and whether the microenvironment is suitable for seedling establishment, etc., to evaluate suitable restoration species. At the same time, we would monitor the effectiveness of the two ways of artificial restoration methods of staking and sowing in rills, and seedling transplanting. This project will compare the survival and growth of trees in the two artificial ways and compare the feasibility for restoration of different trees. The above result could serve as the basis for the artificial restoration methods and tree species selection in the future landslide. The invasion of Leucaena leucocephala has caused an ecological crisis in the natural environment in Taiwan. Nowadays, the mechanical removal or cutting of L. leucocephala and reforestation immediately are the most effective methods for the prevention and control of their population. Afforestation still needs to take 6-9 years to establish a closed canopy. Therefore, this project aims to use native species for afforestation. Utilizing the characteristics of the growth rapidly of the native species can prompt the closure of the canopy rapidly. Planting native species not only could save the cost of afforestation, but also accelerate the prevention and control of L. leucocephala. Leucaena leucocephala, an exotic invasive species, has spread widely and seriously threatened the natural ecosystem in Kenting National Park. The major tasks in 2023 are: 1. Survival and growth survey of restoration seedlings planted in 2007; 2. evaluating the performance of direct seeding. The growth information of direct seeding plants will be an essential reference for future restoration plan in Hengchun peninsula.