نتایج جستجو برای: forest plot was employed results

تعداد نتایج: 5609628  

2010
W. John Kress David L. Erickson Nathan G. Swenson Jill Thompson Maria Uriarte Jess K. Zimmerman

BACKGROUND Species number, functional traits, and phylogenetic history all contribute to characterizing the biological diversity in plant communities. The phylogenetic component of diversity has been particularly difficult to quantify in species-rich tropical tree assemblages. The compilation of previously published (and often incomplete) data on evolutionary relationships of species into a com...

2017
Ville Luoma Ninni Saarinen Michael A. Wulder Joanne C. White Mikko Vastaranta Markus Holopainen Juha Hyyppä

Forest resource information has a hierarchical structure: individual tree attributes are summed at the plot level and then in turn, plot-level estimates are used to derive stand or large-area estimates of forest resources. Due to this hierarchy, it is imperative that individual tree attributes are measured with accuracy and precision. With the widespread use of different measurement tools, it i...

Journal: :Remote Sensing 2013
Mikko Vastaranta Tuula Kantola Päivi Lyytikäinen-Saarenmaa Markus Holopainen Ville Kankare Michael A. Wulder Juha Hyyppä Hannu Hyyppä

The mapping of changes in the distribution of insect-caused forest damage remains an important forest monitoring application and challenge. Efficient and accurate methods are required for mapping and monitoring changes in insect defoliation to inform forest management and reporting activities. In this research, we develop and evaluate a LiDAR-driven (Light Detection And Ranging) approach for ma...

2002
K. J. Raat

This study focuses on spatial variability of throughfall water and chemistry and forest floor water content within a Douglas fir (Pseudotsuga menziesii, Franco L.) forest plot. Spatial patterns of water and chemistry (NH4 +, NO3 -, SO4 2-, Cl-, Mg2+, Ca2+, Na+ and K+) were compared and tested for stability over time. The spatial coefficient of variation (CV) was between 18 and 26% for amounts o...

1985
C. L. BATCHELER

The properties of a variable area sampling technique, by which the observer varies the searchradius to obtain approximately a prescribed number of woody plants in each tier measured, were determined by (i) comparison of fixed area and variable area sampling of a computer-mapped shrub population; (ii) comparison of results from fixed area and variable area sampling of woody plants exceeding abou...

2017
KaDonna Randolph

The USDA Forest Service Forest Inventory and Analysis (FIA) program makes and keeps current an inventory of all forest land in the United States. To comply with privacy laws while at the same time offering its data to the public, FIA makes approximate plot locations available through a process known as perturbing (“fuzzing”) and swapping. The free spatial scanning software program SaTScan toget...

In the current study, conservation strategies were employed for the spatial analysis of forest fragmentation and field assessment approaches in a forest landscape of Central Zagros, in the western part of Isfahan province, Iran. Vegetation and soil properties were accordingly studied in 15 forest sites with various densities including dense, semi-sparse and sparse-forests with 839.2 km2. In the...

2008
Kevin M. Potter

Forest genetic sustainability is an important component of forest health because genetic diversity and evolutionary processes allow for the adaptation of species and for the maintenance of ecosystem functionality and resilience. Phylogenetic community analyses, a set of new statistical methods for describing the evolutionary relationships among species, offer an innovative approach for assessin...

      Taxus baccata L. is a native and ancient tree species growing the Hyrcanian forests that have been considered in recent years because of being in the red lists of threated species. The aim of this research was to provide quantitative characteristics of forest stand structure using a set of indicators in the natural habitat of this species. Three one-hectare sampling area were selected to ...

2004
J. Holmgren T. Jonsson

The first large scale laser scanning project in Sweden for the purpose of forest inventory was started by a regional forestry board in central Sweden. The objective was to compare laser scanning with traditional operational methods for large area forest variable estimations. Laser data were acquired for a 50 km forest area in central Sweden with approximately 1.2 laser measurements per square m...

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