نتایج جستجو برای: canopy decreasing

تعداد نتایج: 103479  

Importance of probability distribution functions in natural resource studies is increasing due to their effective roles in better understanding of vegetation structure and providing conceptual models of quantitative indices of plant species. The present study was performed to model the distribution of height and canopy area of Cionura erecta L. shrub, using probability distribution functions in...

2014
G. P. Asner C. B. Anderson R. E. Martin D. E. Knapp R. Tupayachi F. Sinca

Elevation gradients provide opportunities to explore environmental controls on forest structure and functioning. We used airborne imaging spectroscopy and lidar (light detection and ranging) to quantify changes in threedimensional forest structure and canopy functional traits in twenty 25 ha landscapes distributed along a 3300 m elevation gradient from lowland Amazonia to treeline in the Peruvi...

2017
Qingfeng Song Yu Wang Mingnan Qu Donald R Ort Xin-Guang Zhu

Canopy photosynthesis (Ac ) describes photosynthesis of an entire crop field and the daily and seasonal integrals of Ac positively correlate with daily and seasonal biomass production. Much effort in crop breeding has focused on improving canopy architecture and hence light distribution inside the canopy. Here, we develop a new integrated canopy photosynthesis model including canopy architectur...

The aim of this research is exploring the impact of changes in runoff and sediment of the upstream catchment on the changes in the area and amount of canopy in Gabric-Jask mangrove. Hence, hydro-climatological parameters including amount of precipitation, discharge, and sediment in Gabric catchment during the statistical period of 1993 to 2010 were selected and the annual standardized index rel...

2012
Erynn E. Maynard Stephen Brewer

Fire suppression has removed an important ecological force previously responsible for shaping many plant communities throughout the world. Upland areas of northcentral Mississippi that have been protected from fire are now closed-canopy forests including species known to be uncommon as bearing/witness trees in upland portions of the landscape (historically off-site species) and sparse ground co...

The arid regions are fragile and sensitive ecological environment and are vulnerable to desertification. This critical area around arid region where desertification occurs determines the ecological stability of the deserts. In order to combat desertification and decreasing its risks, the restoration projects using varieties of plant species were applied that could change the soil properties and...

2008
MIRMOSADEGH JAMALI XUEYAN ZHANG HEIDI M. NEPF H. M. Nepf

This paper theoretically and experimentally investigates the exchange flow due to temperature differences between open water and a canopy of aquatic plants. A numerical model is used to study the interfacial shape, frontal velocity and total volumetric exchange, and their dependence on a dimensionless vegetation drag parameter. The numerical predictions are consistent with the laboratory measur...

Journal: :iranian journal of natural resources research 2012
neda ghorbanzadeh ali salehi ebrahim lashkar bolooki ehsan kahneh

poplar trees are becoming extremely important as fast growing species due to the increasing need for wood and decreasing productivity of some lands in iran. the present study aimed to find the effect of canopy of poplar clones as one of the most important effective factors on soil properties compared to the distances inter-row trees. five poplar clones and species included: populus euramericana...

Due to the harsh environmental conditions in arid and semi-arid area of country, it is essential to assess the factors affecting the vegetation in such areas. This study aimed to investigate the effect of some soil physicochemical properties (including texture, bulk density, moisture, organic matter, carbon, nitrogen, potassium, lime, sodium, electrical conductivity and pH) on Haloxylon persicu...

2001
Marinus Werger

Growth rates of seedlings of eight tropical rain forest tree species were compared under five different canopy openness levels (FU and 50, 200, 800, 3200 m gaps). RGR exhibited a positive relation with canopy openness with species attaining their highest RGR at the 800 m (4 species) or 3200 m (3 species) gaps. Seed mass and RGR were negatively related. The increase in RGR between small and larg...

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