The Metolius Research Natural Area (RNA), located 29 km northwest of Sisters, Oregon, was originally established in 1931 to maintain a ponderosa pine (Pinus ponderosa Dougl. Ex Laws) and dry, mixed-conifer forest with the aim to meet objectives of preserving natural conditions, providing for research opportunities, and preserving gene pools...
Forest species classifications are becoming increasingly automated as advances are made in machine learning. The algorithms used to identify tree species range from simple decision trees to intricate neural networks, and often excel in accurately delineating tree species. However, complex algorithms can have high input costs, including the cost of...
Wildland fires are an increasingly extensive, expensive, and frequent occurrence in dry forests of the western United States. Fuel reduction treatments are designed to reduce extreme fire behavior, promote resilient forest structure, and facilitate fire control efforts. Although there is widespread recognition that repeated treatments are needed to maintain desired...
It is uncertain how predicted changes in climate will impact vegetation responses and plant species’ distributions because the physiological mechanisms underlying thresholds for damage are not well understood, and responses to stress vary by functional type and developmental stage. Thus, it is crucial to investigate physiological responses to heat and...
................................................................................................... 93
4. Thermotolerance and heat stress responses of Douglas-fir and ponderosapine seedling
This study explored the relationship of mature ponderosa pine (Pinus ponderosa Dougl. ex Laws) tree vigor and competitive zone density following thinning and fuel reduction treatments. Competitive zone density (CZD) was defined as the total tree basal area (m²/ha) surrounding a given ponderosa pine tree within a 10m fixed radius...
Fuel accumulation and climate shifts are predicted to increase the frequency of high-severity fires in ponderosa pine (Pinus ponderosa Dougl. ex Laws) forests of central Oregon. The combustion of fuels containing large downed wood can result in intense soil heating, alteration of soil properties, and mortality of microbes. Previous studies...
Vegetation patterns and species distributions are strongly linked to soil moisture regimes, and populations within a species from contrasting climatic regimes could exhibit differences in the degree to which certain functional traits related to establishment are expressed. Tree seedling survival is crucial for forest regeneration, and thus may be a...