نتایج جستجو برای: average of canopy cover diameter
تعداد نتایج: 21187469 فیلتر نتایج به سال:
The present study eas aimed to evaluate the potential of ALS data in estimation of individual canopy cover area and tree heights for the part of Shast Kalate of Gorgan. In this study 117 tree that located in dominant forest story and without overlay with adjacent trees, were selected. Center coordinates of sample trees were determined using DGPS system. Individual canopy area and tree heights w...
Habitat loss and chytridiomycosis (a disease caused by the chytrid fungus Batrachochytrium dendrobatidis - Bd) are major drivers of amphibian declines worldwide. Habitat loss regulates host-pathogen interactions by altering biotic and abiotic factors directly linked to both host and pathogen fitness. Therefore, studies investigating the links between natural vegetation and chytridiomycosis requ...
Large-scale field patterns are a fundamental source of inferences on processes responsible for variation in species richness among habitats. We examined species richness of larval amphibian communities in 37 ponds over seven years on the Univ. of Michigan’s E. S. George Reserve. Ordination of the community incidence matrix indicated a strong major axis of variation in species associations that ...
Accurate estimates of forest canopy are essential for the characterization of forest ecosystems. Remotelysensed techniques provide a unique way to obtain estimates over spatially extensive areas, but their application is limited by the spectral and temporal resolution available from these systems, which is often not suited to meet regional or local objectives. The use of unmanned aerial vehicle...
In 2011, Big Bend National Park, Texas, USA, experienced the most severe single year drought in its recorded history, resulting in significant plant mortality. We used this event to test how perennial plant response to drought varied across elevation, plant growth form and leaf traits. In October 2010 and October 2011, we measured plant cover by species at six evenly-spaced elevations ranging f...
One of the most suitable and efficient solutions for proper use of flood potential and saline ephemeral rivers in arid and desert areas is the use of flood spreading networks with a special design that while separating the saline base flow from the flood, water also increases forage production and improves the quantity and quality of pastures and desertification control. The purpose of this stu...
Humans are rapidly altering natural systems, leading to changes in the distribution and abundance of species. However, so many changes are occurring simultaneously (e.g., climate change, habitat fragmentation) that it is difficult to determine the cause of population fluctuations from correlational studies. We used a manipulative field experiment to determine whether forest canopy cover directl...
In the coastal temperate rainforests of southeast Alaska, much progress has been made in describing landscape-level natural disturbances and formulating management systems that emulate those disturbances. Little is known, however, concerning canopy gaps, the dominant form of natural disturbance in the region. During June–August, 1991–1993, we characterized canopy gap patterns and dynamics at th...
a significant problem in multicarrier communication systems is the necessity to reduce the value of papr (peak-to-average power ratio) of transmitting signal. in this thesis we study the effect of the system parameters such as coding and modulation types on papr and ultimate ber in a mc-cdma system. in this study we consider fading channel as well as the nonlinearity of transmitter’s amplifier ...
The study of plant communities is the best way to learn about vegetation structure and distribution as well as various interactions among the plants in an ecosystem. Elevation factor plays a vital role in plant distribution that ultimately leads to specific phytogeographic regions. This study evaluated the changes in species composition, density, frequency, canopy cover and palatability of spec...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید