نتایج جستجو برای: crown diameter

تعداد نتایج: 129405  

2003
Jouni Kalliovirta Timo Tokola

The aim was to investigate the relations between diameter at breast height and maximum crown diameter, tree height and other possible independent variables available in stand databases. Altogether 76 models for estimating stem diameter at breast height and 60 models for tree age were formulated using height and maximum crown diameter as independent variables. These types of models can be utiliz...

Journal: :iranian journal of natural resources research 2012
hossein mirzaie-nodoushan ali mirhosseini fereshteh asadi-corom

black saxaul (haloxylon aphyllum) is one of the best options for rehabilitating drought affected desert lands. the species is remarkably adapted to the central dry environment ofiran and a major source of raising pasture productivity of the areas. progenies of 25 randomly selected black saxaul trees from four populations of the species were studied in a randomized complete block design with thr...

Journal: :Ecological applications : a publication of the Ecological Society of America 2014
Rosa C Goodman Oliver L Phillips Timothy R Baker

Tropical forests play a vital role in the global carbon cycle, but the amount of carbon they contain and its spatial distribution remain uncertain. Recent studies suggest that once tree height is accounted for in biomass calculations, in addition to diameter and wood density, carbon stock estimates are reduced in many areas. However, it is possible that larger crown sizes might offset the reduc...

Journal: :Remote Sensing 2011
Christoph Straub Barbara Koch

So far, only a few studies have been carried out in central European forests to estimate individual tree stem volume of pine trees from high resolution remote sensing data. In this article information derived from airborne laser scanner and multispectral line scanner data were tested to predict the stem volume of 178 pines (Pinus sylvestris) in a study site in the south-west of Germany. First, ...

Journal: :ecopersia 0
abdolreza javidfar former m.sc. student of range management, university of zabol, zabol, iran einollah rouhi-moghaddam associate professor, department of range and watershed, university of zabol, zabol, iran mahdieh ebrahimi associate professor, department of range and watershed, university of zabol, zabol, iran

the effect of soil and topographic features on distribution of amygdalus scoparia in nehbandan (iran) was investigated. slope, aspect and altitudinal maps were overlaid to prepare a working map unit. quantitative and qualitative traits, including height, number, collar diameter of sprout with the highest diameter, crown diameter and trunk health were recorded in 1000 m2 plots (27 plots). in eac...

Journal: :American journal of physical anthropology 2005
Simon Hillson Charles Fitzgerald Helen Flinn

Most archaeological and fossil teeth are heavily worn, and this greatly limits the usefulness of tooth crown diameter measurements, as they are usually defined at the widest points of the crown. There are alternatives, particularly measurements at the cervix of the tooth, where the crown joints the root, and measurements along a diagonal axis in molars, that are much less affected by wear. Thes...

2010
Benjamin S. Ramage Kevin L. O’Hara

Tanoak (Notholithocarpus densiflorus syn. Lithocarpus densiflorus) is one of the most widespread and abundant associates of coast redwood (Sequoia sempervirens), but little is known about the structural relationships between these two species. Knowledge of such relationships is essential for a thorough understanding of the impacts of sudden oak death (caused by the exotic pathogen Phytophthora ...

2013
TOMISLAV DUBRAVAC MARTIN BOBINAC DAMIR BARI VLADIMIR NOVOTNY

Background and Purpose: Structure of crowns in forest stands is one of the main factors which determines growth and development of trees. Dynamic change occurs with the age of the stand due to silvicultural interventions or natural disturbances during which trees are removed from the stand. The aim of this article is to analyse the structure of the crown shape of pedunculate oak and common horn...

2015
Jessica Preisler Julia Kopeika Laure Ismail Veluppillai Vathanan Jessica Farren Yazan Abdallah Parijat Battacharjee Caroline Van Holsbeke Cecilia Bottomley Deborah Gould Susanne Johnson Catriona Stalder Ben Van Calster Judith Hamilton Dirk Timmerman Tom Bourne

OBJECTIVES To validate recent guidance changes by establishing the performance of cut-off values for embryo crown-rump length and mean gestational sac diameter to diagnose miscarriage with high levels of certainty. Secondary aims were to examine the influence of gestational age on interpretation of mean gestational sac diameter and crown-rump length values, determine the optimal intervals betwe...

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