With fire suppression, many western forests are expected to have fewer gaps and higher stem density of shade-tolerant species as light competition becomes a more significant influence on stand pattern and composition. We compared species composition, structure, spatial pattern, and environmental factors such as light and soil moisture between two old-growth forests: Pacific Northwest western he...

Physical perturbation of a plant canopy brought about by wind is a ubiquitous phenomenon and yet its biological importance has often been overlooked. This is partly due to the complexity of the issue at hand: wind-induced movement (or mechanical excitation) is a stochastic process which is difficult to measure and quantify; plant motion is dependent upon canopy architectural features which, unt...

Planting shrub seedlings under oil mulches has frequently been used for stabilizing mobile sands in Iran for during the last three decades. Sandy desert of Samad Abad, Sarakhs, northeast Iran, has been fixed by cultivating seedling of Haloxylon aphyllum under the oil mulches. Therefore this study was designed to investigate the effects of the sand fixation project on soil and vegetation propert...

This study used an affordable ground-based portable LiDAR system to provide an understanding of the structural differences between old-growth and secondary-growth Southeastern pine. It provided insight into the strengths and weaknesses in the structural determination of portable systems in contrast to airborne LiDAR systems. Portable LiDAR height profiles and derived metrics and indices (e.g., ...

The Southwestern United States desert serves as the host for several threatened and endangered species, one of which is the desert tortoise (Gopherus agassizii). The goal of this study was to develop a fine-scale, remote-sensing-based approach that indicates favorable burrow locations for G. agassizii in the Boulder City (Nevada) Conservation Easement area (35,500 ha). This was done by analyzin...

Virtual plant models of plant architecture have been developed to examine the impact of canopy structure and connectedness on the location of prey by randomly moving predators. The results show that as canopy connectedness increases, the time to locate a static prey decreases, but that the time to prey location increases with the complexity of the canopy. These results are important for the dev...

Solar radiation directly and indirectly drives a variety of ecosystem processes. Our aim was to evaluate how tree canopy architecture affects near-ground, incoming solar radiation along gradients of increasing tree cover, referred to as the grassland–forest continuum. We evaluated a common type of canopy architecture: tall trees that generally have their lowest level of foliage high above, rath...

Consumer-plant interactions can alter the outcome of biological invasions when native and exotic plants differ systematically in their resistance to and/or tolerance of consumer impacts. Given evidence for indirect interactions and shifts in plant communities from the few existing long-term studies, it is clear that long-term studies are a critical component for understanding the role of consum...

Few studies have considered how interactions between woody and herbaceous species change in direction or magnitude over time or with traits of the dominant woody species. We used a chronosequence approach to explore these interactions in a montane meadow in which Pinus contorta Dougl. ex Loud. and Abies grandis (Dougl. ex. D. Don) Lindl. have established gradually over a period of >70 years. Ef...

this study was carried out to investigate the effect of crown canopy of ziziphus spina-christi on seed bank characteristics (density and similarity with above ground flora) in two sites with saline-alkaline and alkaline soils. in each soil, forty plots were established, half in and half outside of z. spina-christi cover. in each plot, soil sampling was done from 0-5 and 5-10 cm depths. paired a...