We investigated population responses in physiology, morphology, and growth of mature Pinus ponderosa trees to an environmental gradient across Nebraska, USA. Ten populations from western Nebraska and eastern Wyoming were grown in three 26-year-old provenance tests from the warmest and wettest site in the east (Plattsmouth) to the intermediate site in the middle (Halsey) to the coldest and dries...

The objective of this paper was to predict a model for describing stand structure of tree heights (h) and diameters at breast height (dbh). The research material consisted of data collected from 64 stands of Norway spruce (Picea abies Karst.) and 91 stands of Scots pine (Pinus sylvestris L.) located in southern Finland. Both stand types contained birch (Betula pendula Roth and B. pubescent Ehrh...

High tree mortality due to drought and insects often is assumed to increase fire severity once ignition occurs. In 2002-2003, coniferous forests in the San Bernardino Mountains, California experienced a significant tree mortality event due to drought and an outbreak of western pine beetles (Dendroctonus brevicomis). In October 2003, fire burned approximately 5,860 ha of conifer forest types in ...

In southeastern Arkansas, pine growth was monitored for 19 yr after mechanically strip thinning a dense, naturally regenerated, even-aged stand of Gyr-old loblolly pines (Pinus taeda L.) and shortleafpines (P. echinata Mill.) that averaged 16,600 stems/UC. Prescribed winter burns were conducted biennial ly between ages 9 and 20 yr and at 24 yr . Commercial th innings during the 17th and 23rd gr...

this study aims at assessing the impact of land use change (from forest areas to forest parks) on some silvicultural characteristics of stands under recreational land use in boloran natural forest park, kuhdasht. for this purpose, three zones including non-recreation, extensive recreation and intensive recreation regions were chosen. in each zone 30 sample plots in a systematic random design (1...

Vascular epiphytes are an understudied and particularly important component of tropical forest ecosystems. However, owing to the difficulties of access, little is known about the properties of epiphyte-host tree communities and the factors structuring them, especially in Asia. We investigated factors structuring the vascular epiphyte-host community and its network properties in a tropical monta...

Traditional forest inventories are based on field surveys of established sample plots, which involve measurements individual trees within a plot and the selection proper allometric equations for tree volume calculation. Thus, accurate properly selected two crucial factors providing high-quality volumes. One key problem is difficulty in accurately acquiring height data, resulting high uncertaint...

Invasive pathogens are becoming increasingly important in forested ecosystems, yet they are often difficult to study because of their rapid transmission. The rate and extent of pathogen spread are thought to be partially controlled by variation in host characteristics, such as when host size and location influence susceptibility. Few host-pathogen systems, however, have been used to test this p...

Porcupines (Erethizon dorsatum) rely on trees and shrubs for winter food and can cause serious, localized damage to conifers. Twenty-two percent of ponderosa trees (Pinus ponderosa) examined in southeastern Washington were damaged by porcupines. Most damage involved complete girdling of the midto upper boles of the larger trees (12 to 30 cm dbh) in the stand. Preliminary repellent trials with c...

In this study the quantification of biomass within all relevant compartments of a three-year-old poplar clone (P. maximowicii × P. trichocarpa) planted on abandoned agricultural land at a density of 5000 trees ha −1 is presented. A total of 30 trees within a diameter range of 1.8 cm to 8.9 cm, at breast height (dbh at 1.3 m), were destructively sampled. In order to analyze the biomass, the comp...