Background Forest soils are considered sinks for atmospheric C. Many studies revealed that tree species and their mycorrhizal association affect forest floor topsoil organic C (OC) total N, while the knowledge of effect on subsoil OC N is still scarce. Aims We aimed to identify (1) effects floor, (0–30 cm) (30–80 stocks vertical distribution (2) drivers soil distribution. Methods sampled under ...

Massive tree dieback has occurred periodically in the Hawaiian montane rain forest. The species mainly involved is Metrosideros polymorpha, which is the prevailing upper canopy tree species throughout most of this forest on all high Hawaiian islands. The canopy dieback occurs in stands over the entire spectrum of sites, from well-drained lava flows over nutritionally rich volcanic ash to perman...

Emerald Ash Borer (EAB: Agrilus planipennis Fairmaire) is an invasive species which was introduced to the North America around the year 2002. We assume that the temperature drops will significantly increase the maturation time of EAB. A mathematical model will be constructed to study the effects of temperature variations in the population densities of EAB. The outcome predictions of this study ...

Previous studies with different experimental methods have demonstrated that photosynthesis significantly influences soil respiration (RS). To compare the experimental results of different methods, RS after girdling and defoliation was measured in five-year-old seedlings of Fraxinus mandshurica from June to September. Girdling and defoliation significantly reduced RS by 33% and 25% within 4 days...

BACKGROUND Of the two known Eupareophora species, more is known about the larva  and bionomics of the Nearctic E. parca, than the rarely recorded West Palaearctic E. exarmata. NEW INFORMATION The last instar larva and prepupa of E. exarmata is illustrated and briefly described. In Germany its host is Fraxinus excelsior.

Objectives: When missing values occur, complete case analysis can cause biased results. In this paper, we discuss imputation methods using machine learning techniques when occurred in ordinal variables. Methods: We consider two techniques, the decision tree and random forest, for of values. use treating variables as ordinal, forest nominal. addition, apply cumulative logistic model. The results...

beech forests in midland areas of hyrcanian forests of iran are the most important forests having the highest degree of naturalness. these forests are the valuable source of wood production and other forest products. one of the most important characteristics of plant communities is the spatial pattern of trees. ecological process in forest ecosystems are directly influenced by the spatial patte...

There is an increasing need for accurate forest inventories to assist forest managers and decision-makers in the planning of their forest resource. Airborne LiDAR methods enable the construction of Tree Canopy Models (TCM) at a fine resolution, thereby facilitating the delineation of individual tree crowns. This information can be useful in predicting forest parameters such as top height, basal...

The first 40 yr of forest succession on permanent plots at the Harvard Forest in central New England followed the initial floristic composition model of forest succession. After the 1938 hurricane removed the previous white pine (Pinus strobus) canopy, species regenerated within 4-6 yr by sprouts, buried seed, and wind-blown seed, with no method of regeneration uniformly contributing more to sp...