نتایج جستجو برای: vegetation understory

تعداد نتایج: 49366  

2012
James D. Haywood

Pine straw harvesting con provide on economic benefit to landowners, but the practice may also change the composition of plant communities. This research was initiated in o 34-yeor-old stand of longleaf pine (Pinus palustris Mill.} established in 1956 to study how pine straw management practices (fertilization, prescribed fire, and straw harvesting) affected plant communities, and herein, effec...

2005
Timothy D. Schowalter Yanli Zhang

We compared canopy arthropod assemblages among overstory conifer and understory angiosperm species at Teakettle Experimental Forest in the Sierra Nevada in California during 1998–2000. Arthropods were sampled from upper, middle, and lower crown levels of one overstory tree of each of the four dominant conifer species (Jeffrey pine, sugar pine, white fir, and incense cedar), and from three under...

Journal: :Tree physiology 2001
K Makkonen H S Helmisaari

We determined fine root biomass and production of 15-, 35- and 100-year-old Scots pine (Pinus sylvestris L.) stands during three growing seasons. Fine roots were sampled by the soil core method. Mean (+/- SE) annual fine root biomass of Scots pine in the 15-, 35- and 100-year-old stands was 220 +/- 25, 357 +/- 21 and 259 +/- 26 g m(-2), respectively. Fine root biomass of the understory vegetati...

2014
L N. Kobziar Alan J. Long Wayne C. Zipperer Jesse K. Kreye Leda N. Kobziar

I. Abstract Mechanical fuels treatments are being widely used in fire prone ecosystems where fuel loading poses a hazard, yet little research examining fuel dynamics, fire behavior, and ecological effects exists, especially in the southeastern US. In order to broaden our understanding of these treatments, effects of mechanical mastication ("mowing") were examined in a common pine ecosystem of t...

2001
REBECCA A. MONTGOMERY ROBIN L. CHAZDON

Identifying factors that influence variation in light availability within forested ecosystems represents an important component in our understanding of the complex determinants of tree seedling regeneration. We assessed the influence of forest structure and canopy tree architecture on spatial heterogeneity of understory light availability in three old-growth and three second-growth forests in l...

2016
Nick A. Cutler Olivia M. Shears Richard T. Streeter Andrew J. Dugmore

The factors that influence tephra layer taphonomy are poorly understood, but vegetation cover is likely to play a role in the preservation of terrestrial tephra deposits. The impact of vegetation on tephra layer preservation is important because: 1) the morphology of tephra layers could record key characteristics of past land surfaces and 2) vegetation-driven variability in tephra thickness cou...

Journal: :journal of agricultural science and technology 2011
o. esmailzadeh s. m. hosseini m. tabari

we assessed the size and composition of the soil seed bank and above-ground vegetation in 52 relevés representing a range of habitats within an old- growth, temperate deciduous forest at hyrcanian region, northern iran. we identified 63 taxa in the seed bank, with an average density of 4202 seeds/spores per m2 by seedling emergence method. hypericum androsaemum, cardamine impatiens, and rub...

2010
Jan Pisek Jing M. Chen Krista Alikas Feng Deng

[1] A new leaf area index (LAI) data set in 10 day intervals with consideration of the understory reflectance and foliage clumping effects over North America for 1 year is developed. The data set brings effectively together measurements from multiple sensors with complementary capabilities (SPOT‐VEGETATION, Multiangle Imaging Spectroradiometer, POLDER). First, the temporal consistency analysis ...

2010
ANTÓNIO FERRAZ LUISA PEREIRA

Plant communities display a vertical structure based on the size and growth pattern of the dominant species. To a large extent, this pattern, called vertical stratification, depends on the climatic zone. Vertical structure analysis consists in detecting the number of layers and their limits within a forest stand. So far, there is a lack of robust approaches applied to airborne laser scanning (A...

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