There is research of regularity of free tree mortality in various age pine stands, growing in Nbl places in master work. Presented this process’s characteristics- amounts of mortality by the number and volume of the tree. We used absolute and relational parameters of free tree mortality. An object of work- 20-140 years old pine stands, which is pure, conditionally average growing in Nbl places. Long-time investigation involved pine of the Jonava district and Berezina reserve (Belarus). Information involved free mortality from various literary sources. Aim- fined a regularity of free tree mortality. A method of work- Barrel method of forestry research was used in outdoor work’s. Inventory of barrel research was repeated 2-3 times in 4-7 years. Without our got information analyze from barrel research we used a method of met analyze, when various authors information of free tree mortality is united in one based object by the source of literature. Results of work- Tree mortality research involved 20-140 years old pine, growing in Nbl places. Our investigation and results analysis shows 2-5% trees mortality (per year) registered in pine samplings; 0,3-6% - in mide-aged pine stands; 1-5% - in premature stands; 5-6% trees mortality in mature stands. Average of size of trees mortality equal: in pine samplings- 4,2 m3/ha per year, in mide-aged stands - 2,7 m3/ha per year, in premature forests - 2,6 m3/ha per year, in mature stands - 2,7 m3/ha per year. Our appointed average and... [to full text]

The structure of a forest stand is characterized by: (a) species composition, (b) age, (c) size (diameter and height), and (d) spatial (horizontal and vertical) arrangement of the trees. Depending on the species, site, and disturbance history, the stand structure varies with time, thus providing a snapshot of a particular development stage. Research on growth and stand structure has shown that the spatial distribution of trees is one of the key determinants of stand productivity. Forest inventories and ecological surveys carried out in British Columbia (BC) have shown that the structure of naturally established, unmanaged stands varies from simple (single-species, single-storied, and even-aged) to complex (multi-species, multi-storied, and uneven-aged). Only a few studies have quantitatively characterized this range of structural complexity, with nearly all studies focusing on old-growth stands. BC forest policy requires that harvested areas be regenerated with a mixture of tree species whenever a mixture is suited to the site. This policy is based upon the assumption that under appropriate conditions, increases in stand productivity, reliability, and/or biodiversity can be attained in mixed-species stands. This assumption has not yet been tested for forest ecosystems. One mechanism by which different tree species can reduce crown competition for light is through vertical separation (the development of multiple canopy strata). Canopy stratification is not easily recognized in mixed-species stands, particularly when species have similar shade tolerance and height growth patterns, and no quantitative methods have been developed to detect stratification. The diameter frequency distribution of two-storied stands have been characterized by inverted J-shaped as well as modal curves. Although it would be more appropriate to characterize stand structure by height frequency distributions, these distributions have not been developed. We suggest that (i) a stand is stratified if there are distinct, quantitatifiable modes in the size distribution; either diameter, height, or crown height, and (ii) height or crown height distributions will be the most sensitive measures. To characterize the structure of western hemlock (Tsuga heterophylla (Raf.) Sarg.) (Hw) and western redcedar (Thuja plicata Donn ex D. Don in Lamb.) (Cw) second-growth stands, and to investigate its influence on tree growth, we (1) described and compared size (diameter, height, and crown height) frequency distributions in single- and mixed-species stands, (2) determined whether mixed-species stands develop a stratified canopy, and (3) examined whether interactions between hemlock and redcedar affect tree growth.

In BC, it is required that harvested areas be regenerated with a mixture of tree species whenever appropriate to the site. This policy is based upon the assumption that increases in stand productivity, reliability, and/or biodiversity can be achieved in mixed-species stands. However, the knowledge justifying this policy is at best incomplete. Differences in forest productivity of mixed-species stands have been attributed mostly to competition. However, an increasing number of studies are providing evidence to support alternate theories, in which positive plant interactions play a major role. Positive plant interactions are divided into two components: (i) competitive reduction through structural and physiological differences in above and below ground structures, and (ii) facilitation through any positive effect on the growing environment of one plant species by another. These theories have yet to be tested in forest ecosystems. The objectives of this study, with respect to naturally established, unmanaged, second-growth stands of western hemlock (Hw) (Tsuga heterophylla (Raf.) Sarg.), western redcedar (Cw) (Thuja plicata Donn ex D. Don in Lamb.), and their mixtures, were: (1) to review the mechanisms of positive plant interactions and their potential to occur in these mixtures, and (2) to compare the productivity of these three stand types, using relative and absolute yield.

Bc. Romana Musilová: Využití dat DPZ pro hodnocení aktuálního stavu a vývoje smrkových porostů v Krkonoších Remote sensing for evaluation of state and development of Spruce stands condition in the Giant Mountains Abstract Monitoring the health status of forest areas using remote sensing methods are still under development. This master thesis focuses on the use of SPOT, Landsat, QuickBird and WorldView-2 images to evaluate condition of spruce stands in Giant Mountains National Park. For these purposes were selected vegetation indices available in the lite- rature. First satellite images were preprocessed and subsequently calculated vegetation indices. From the generally known were used Normalized Difference Vegetation Index, leaf area index and Simple Ratio. Than were calculated Green Vegetation Index and Red Green Index based on the monitoring of needles color changes. To evaluate moistu- re conditions were used indices Foliar Moisture Index and wide-band Normalized Diffe- rential Infrared Index. The goal was a comparison of the results of these indices and assessment of their applicability. Map outputs indices were compared with maps of de- foliation and mortality of coniferous stands by Ing. Milan Stoklasa. Keywords: remote sensing, Norway Spruce stands, Giant Mountains, vegetation indi- ces, SPOT,...

Les peuplements forestiers sont une unité de mesure de base pour l'inventaire forestier et la cartographie. Ils sont définis comme de grandes zones forestières (par exemple, de plus de 2 ha) et de composition homogène en terme d'essence d'arbres et d'âge. Leur délimitation précise est généralement effectuée par des opérateurs humains grâce à une analyse visuelle d'images infrarouges à très haute résolution (VHR). Cette tâche est fastidieuse, nécessite beaucoup de temps et doit être automatisée pour un suivi de l'évolution et une mise à jour efficace. Une méthode fondée sur la fusion des données lidar aéroportées et des images multispectrales VHR est proposée pour la délimitation automatique des peuplements forestiers contenant une essence dominante (pureté supérieure à 75%). C'est une principale tâche préliminaire pour la mise à jour de la base de données de la couverture forestière. Les images multispectrales donnent des informations sur les espèces d'arbres alors que les nuages de point Lidar 3D fournissent des informations géométriques sur les arbres et permettent leur extraction individuelle. Les attributs multimodaux sont calculées, à la fois au niveau des pixels et des objets (groupements de pixels ayant une taille similaire aux arbres). Une classification supervisée est ensuite effectuée au niveau de l'objet afin de discriminer grossièrement les espèces d'arbres existantes dans chaque zone d'intérêt. Les résultats de la classification sont ensuite traités pour obtenir des zones homogènes avec des bordures lisses par la minimisation d'une énergie, où des contraintes supplémentaires sont proposées pour former la fonction énergie à minimiser. Les résultats expérimentaux montrent que la méthode proposée fournit des résultats très satisfaisants en termes d'étiquetage et de délimitation, et ce pour des régions géographiquement très éloignées / Forest stands are the basic units for forest inventory and mapping. Stands are defined as large forested areas (e.g., 2 ha) of homogeneous tree species composition and age. Their accurate delineation is usually performed by human operators through visual analysis of very high resolution (VHR) infra-red images. This task is tedious, highly time consuming, and should be automated for scalability and efficient updating purposes. A method based on the fusion of airborne lidar data and VHR multispectral images is proposed for the automatic delineation of forest stands containing one dominant species (purity superior to 75%). This is the key preliminary task for forest land-cover database update. The multispectral images give information about the tree species whereas 3D lidar point clouds provide geometric information on the trees and allow their individual extraction. Multi-modal features are computed, both at pixel and object levels: the objects are groups of pixels having a size similar to trees. A supervised classification is then performed at the object level in order to coarsely discriminate the existing tree species in each area of interest. The classification results are further processed to obtain homogeneous areas with smooth borders by employing an energy minimum framework, where additional constraints are joined to form the energy function. The experimental results show that the proposed method provides very satisfactory results both in terms of stand labeling and delineation, even for spatially distant regions

Censuses of two 20-acre plots in upper Logan Canyon, Utah, were made by the spot-mapping method during 1970 and 1971 to determine the differences in composition and density of breeding-bird populations in aspen stands of significantly different density and stature. The less dense stand of greater average d.b.h., average height and per cent ground cover had 20 breeding species totalling 615 pairs per 100 acres (expressed as equivalent territories). The more dense stand of smaller trees and brushy undergrowth had 14 breeding species with 267.5 equivalent territories per 100 acres. Nine species were found on both areas. Observations of foraging height were made concurrently with recordings of time spent at various methods of feeding- ground, vi foliage, bark, hover, and hawking- for the birds of the more open stand. Comparison showed that more ground- and low bush-nesters were present on the dense, brushy stand whereas more cavity-nesters were found in the larger trees. Cavity excavation was limited to trees of greater d.b.h. and cavity-dependent birds were thus limited by nest-hole availability. The horizontal, heavy branch stubs preferred by pewees and tree swallows and the high perches and open areas of the olive-sided flycatcher were also limited to the less dense stand. Cassin's finches and pine siskins were not found in the dense stand which had fewer invading conifers and was farther from conifer stands. Attributes of the terrain, foraging sites, nest sites, and location of perches were analyzed as possible proximate factors of habitat selection within aspen.

Grassland birds have declined more than any other guild of birds in North America, largely due to loss and degradation of native grasslands. The Conservation Reserve Program (CRP) has restored some native warm-season grasses (NWSG), but grassland birds continued to decline (-1.1% annually) partly due to the limited acreage converted (1% of southeastern US). Using NWSG in production settings provides profit incentive to landowners while reducing dependency on government programs. Studies examining these production practices and their effect on grassland birds east of the Great Plains are limited. During 2009 – 2010, I surveyed 102 NWSG fields in Kentucky and Tennessee being used for production purposes (control, biofuel, seed, hay, and pasture treatments) to assess bird use and vegetation characteristics. Landscape cover around each field (250, 500, and 1000 m) was digitized from aerial photography. Using analysis of variance (ANOVA), I compared bird (relative abundance, species diversity, and species richness) and vegetation (average height, litter depth, vertical cover, litter cover, and vegetation cover) metrics across the five treatments. Relative abundance for all species, species diversity, and species richness were all greater for seed production fields (P <0.05); other treatments did not differ. Field sparrows (Spizella pusilla) were less abundant (P <0.05) in biofuel than control, hay and graze treatments, whereas eastern meadowlarks (Sturnella magna) and dickcissels (Spiza americana) were more abundant in seed fields. Average vegetation height, vertical cover, percent litter, percent forbs and percent woody plants differed (P <0.05) among treatments. Using Program Mark, I modeled occupancy for field sparrow, red-winged blackbird (Agelaius phoeniceus), eastern meadowlark, and northern bobwhite (Colinus virginianus) using vegetation and landscape cover as covariates. Treatment was influential in field sparrow and eastern meadowlark models, but not those for red-winged blackbird and northern bobwhite. Occupancy for field sparrow and northern bobwhite were affected by woody cover (+), for red-winged blackbird by vegetation height (-), and for eastern meadowlark by litter depth (+) or percent NWSG (+). All four species were negatively affected by forest within 250-m. Use of NWSG in production could increase the amount of available habitat and thus, help conservation efforts for grassland birds.

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in History." Includes bibliographical references (p. 244-255).

In this work is researching the behaviour peculiarity of wolves and the public opinion towards wolves. The aim – to investigate the wolves’ tracks and the harm of wolves to livestock in Gulbinas forest and in district of this forest; to evaluate the local public opinion towards wolves. The object –the local wolves’ population living in Gulbinas forest and neighborus lesser forests (Vileišiškiai, Vaitutiškiai, Daugmaudžiai, Skobiškiai and Aušgiriai) also agricultural land between these forests in northern part Šiauliai district. Methods – the behaviour of wolves was investigated by snow tracking method; the harm and the public opinion towards wolves were investigated by questionnaire method. Technical tools – global position estimation appliance GPS „EMAP“, computer programme ARCWIEW GIS 3.2. Results – Directional tracks of wolves may be founded in various age stands and clear cut areas. So it can be that farming in the forests does not do the substantial influence to wolves’ choice of tracks. But it’s observes the tendency, that wolves give the priority to more older stands and avoid clear cut areas. Mostly were attacked young animals up to 1 year old (76%). They make the most big part (4,8%) of livestock killed through the year from the all number of young livestock. Mostly livestock were attacked during July - August (76%), less during Sepember – (24%).

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2007. / Härtill 11 uppsatser.