Open Access. Powered by Scholars. Published by Universities.®
Other Forestry and Forest Sciences Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Other Forestry and Forest Sciences
Smallholder Farmers, Environmental Change And Adaptation In A Human-Dominated Landscape In The Northern Highlands Of Rwanda, Apollinaire William
Smallholder Farmers, Environmental Change And Adaptation In A Human-Dominated Landscape In The Northern Highlands Of Rwanda, Apollinaire William
Antioch University Full-Text Dissertations & Theses
Climate change and crop intensification are key challenges to the livelihoods and wellbeing of the majority of rural smallholder farmers in developing countries, particularly in human-dominated, climate-sensitive landscapes such as the northern highlands of Rwanda where issues of fluvial floods, soil erosion pose serious threats to the livelihoods of smallholder farmers. In this mixed methods study conducted between August and December 2015, I explored smallholder farmers’ perceptions by examining what barriers might hinder the process of agroforestry adoption by smallholder farmers, what socio-economic and physical factors and attitudes influence crop choices, motivations for smallholder farmers’ willingness to plant trees within …
Shape Indexes For Semi-Automated Detection Of Windbreaks In Thematic Tree Cover Maps From The Central United States, Greg C. Liknes, Dacia M. Meneguzzo, Todd A. Kellerman
Shape Indexes For Semi-Automated Detection Of Windbreaks In Thematic Tree Cover Maps From The Central United States, Greg C. Liknes, Dacia M. Meneguzzo, Todd A. Kellerman
USDA Forest Service / UNL Faculty Publications
Windbreaks are an important ecological resource across the large expanse of agricultural land in the central United States and are often planted in straight-line or L-shaped configurations to serve specific functions. As high-resolution (i.e., <5 m) land cover data sets become more available for these areas, semi-or fully-automated methods for distinguishing windbreaks from other patches of trees are needed for use with thematic raster data sets. To address this need, we created three shape indexes: a morphology-based index that we have named the Straight and Narrow Feature Index (SNFI), a windbreak sinuosity index, and an area index indicating the occupied fractional area of a bounding box. The indexes were tested in two study areas: (1) a riparian area dominated by sinuous bands of trees but mixed with row crop agriculture and (2) an agricultural area with a mix of straight-line and L-shaped windbreaks. In the riparian area, a Kruskall–Wallis rank sum test indicated class differences for all three indexes, and pairwise comparisons indicate windbreaks and riparian trees are separable using any of the three indexes. SNFI also produced significant differences between windbreaks oriented in different directions (east–west vs. north–south). In the agricultural area, the Kruskall–Wallis rank sum test indicated differences between classes for all three indexes, and pairwise comparisons show that all class pairs have significant differences for at least one index, with the exception of L-shaped windbreaks vs. non-windbreak tree patches. We also used classification trees to objectively assign representative samples of tree patches to classes using both single indexes and multiple indexes. Classes were correctly assigned for more than 90% of the samples in both the riparian and agricultural study areas. In the riparian area, combining indexes did not improve accuracy compared to using SNFI alone, whereas in the agricultural area, combining the three indexes produced the best result. Thematic data sets derived from high-resolution imagery are becoming more available, and extracting useful information can be a challenge, partly due to the large amount of data to assess. Calculating the three shape indexes presented can assist with efficient identification of candidate windbreaks and as such, hold good promise for value-added analysis of tree function in the central United States.
Carbon Storage Potential Of Windbreaks On Agricultural Lands Of The Continental United States, William Ballesteros Possu
Carbon Storage Potential Of Windbreaks On Agricultural Lands Of The Continental United States, William Ballesteros Possu
School of Natural Resources: Dissertations, Theses, and Student Research
Agricultural production systems face major challenges under climate change scenarios in terms of expected negative impacts on productivity and persistence of the crops. Greenhouse gases from agriculture continue to rise although not as fast as from other fossil fuel-based human activities. Windbreaks perform several ecosystems functions that improve the local and regional capacity of crop systems to increase yields and offer environmental services by minimizing the negative effects of extreme weather events. Windbreaks also represent an important means of mitigating greenhouse gas emissions. This is predominantly accomplished by the windbreak trees storing carbon (C) in their above and belowground woody …