Issue/Heft 11 (2011)

Details

© AFSV; Waldökologie, Landschaftsforschung und Naturschutz (Forest Ecology, Landscape Research and Nature Conservation) - Heft 11, 2011

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Impressum und Inhaltsverzeichnis

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RUSS, A., RIEK, W: Pedotransferfunktionen zur Ableitung der nutzbaren Feldkapazität – Validierung für Waldböden des nordostdeutschen Tieflands

(Pedotransfer functions for estimation of plant available water capacity – validation for forest soils of the north-eastern lowlands)

Abstract
The available water capacity (AWC) of especially coarse-textured forest soils of the federal state of Brandenburg - estimated by various pedotransfer functions (PTF) – induce huge systematic differences. Thus further validations of the PTF seem to be necessary. The PTF were evaluated, using a dataset of overall 489 forest soil horizons of the north-eastern lowlands. The dataset includes measured AWC-values and further soil parameters required for the PTF. The comparison of measured and estimated AWC-values indicates that PTF, which were developed using large, geographically widespread datasets and which consider especially soils similar to those of the validation sample respectively, tend to smaller systematic prediction errors. The PTF, which consider a higher number of predicting variables generally induce higher coefficients of determination. The lowest overall error (square root of the mean square prediction error) was determined for the PTF Renger et al. (2009). The highest values describing the strength and accuracy of the linear relationship between measurements and predictions (coefficient of determination and slope) were found out for the approach of Riek et al. (1992, 1995).

>> Volltextversion (pdf 1.9 M; Heft 11-Aufsatz 3; Original paper; Language: Deutsch; urn:nbn:de: 0041-afsv-01139)

PROMIS, A., GÄRTNER, S., BUTLER-MANNING, D., DURÁN-RANGEL, C., REIF, A., CRUZ, G., HERNÁNDEZ; L.: Comparison of four different programs for the analysis of hemispherical photographs using parameters of canopy structure and solar radiation transmittance

(Vergleich von vier verschiedenen Programmen zur Analyse von Fischaugenfotografien unter Berücksichtigung von Paramatern zur Kronenstuktur und zur Durchlässigkeit von Sonnenstrahlung)

Abstract
There have been many studies involving the use of hemispherical photographs to indirectly estimate canopy structures and forest light environments. A variety of commercial and free software packages are available for the analysis of hemispherical photographs. The costs of investment might represent an advantage of the free programmes over the commercial, but as yet little has been documented about the differences in their outputs and in the technical applications from a user (ecologist and forester) perspective. The objective of the study was to compare the canopy structure variables (canopy openness and effective plant area index) and solar radiation transmission estimates (direct, diffuse and global solar radiation transmittances) from digital hemispherical photographs taken under two forest canopy conditions (gap and closed canopy) in three different broadleaf forest regions (Chile, Germany, Venezuela) and calculated using four different programmes. The hemispherical photographs were analysed using one commercial (HemiView) and three free programmes (Gap Light Analyzer, hemIMAGE and Winphot). The results obtained revealed that all of the programmes computed similar estimates of both canopy structures and below-canopy solar radiation. Only the results relating to the effective plant area index with an ellipsoidal leaf angle distribution made with HemiView and Winphot deviated significantly. Other user aspects are also discussed, such as costs, image formats, computer system requirements, etc

>> Volltextversion (pdf 1.4 M; Heft 11-Aufsatz 1; Original paper; Language: English; urn:nbn:de:0041-afsv-01117)

FISCHER, A., BLASCHKE, M., BÄSSLER, C.: Altitudinal gradients in biodiversity research: the state of the art and future perspectives under climate change aspects

(Höhengradienten in der Biodiversitäts-Forschung: Eine Übersicht unter Berücksichtigung des Klimawandels)

Abstract
Mountains, with their isolated position and altitudinal belts, are hotspots of biodiversity. Their flora and fauna have been observed worldwide since the days of Alexander von Humboldt, which has led to basic knowledge and understanding of species composition and the most important driving forces of ecosystem differentiation in such altitudinal gradients. Systematically designed analyses of changes in species composition with increasing elevation have been increasingly implemented since the 1990s. Since global climate change is one of the most important problems facing the world this century, a focus on such ecosystem studies is urgently needed. To identify the main future needs of such research we analyze the studies dealing with species changes of diverse taxonomical groups along altitudinal gradients (0 to 6,400 m a.s. l.) on all continents, published during the past one to two decades. From our study we can conclude that although mountains are powerful for climate change research most studies have to face the challenge of separating confounding effects driving species assemblages along altitudinal gradients. Our study therefore supports the view of the need of a global altitudinal concept including that (1) not only one or a few taxonomical groups should be analyzed, but rather different taxonomical groups covering all ecosystem functions simultaneously; (2) relevant site conditions should be registered to reveal direct environmental variables responsible for species distribution patterns and to resolve inconsistent effects along the altitudinal gradients; (3) transect design is appropriate for analyzing ecosystem changes in site gradients and over time; (4) both the study design and the individual methods should be standardized to compare the data collected worldwide; and (5) a long-term perspective is important to quantify the degree and direction of species changes and to validate species distribution models. (6) Finally we suggest to develop experimental altitudinal approaches to overcome the addressed problems of biodiversity surveys.

>> Volltextversion (pdf 645 K; Heft 11-Aufsatz 4; Original paper; Language: English; urn:nbn:de:0041-afsv-01140)

BUDDE, S., SCHMIDT, W., WECKESSER, M.: Impact of the admixture of European beech (Fagus sylvatica L.) on plant species diversity and naturalness of conifer stands in Lower Saxony

(Auswirkungen der Einbringung von Buche (Fagus sylvatica L.) auf die Artendiversität und Naturnähe von Nadelholzbeständen in Niedersachsen)

Abstract
The promotion and extension of continuous cover mixed stands with a simultaneous reduction of conifer-monocultures play a major role in current silvicultural practices in Central Europe. It is assumed that the admixture of the natural dominant beech (Fagus sylvatica) in pure non site-specific conifer stands automatically indicates better conditions in terms of nature conservation and forest management. To test this hypothesis three different conifer-beech-comparisons of pure and mixed stands in Lower Saxony are studied, analyzing plant species diversity and naturalness of understorey vegetation as one important indicator for the ecological status of forests. Each comparison includes pure coniferous stands (Picea abies, Pinus sylvestris, Pseudotsuga menziesii), mixed coniferous-beech-stands, and pure beech stands on similar acidic mineral soils where the potential natural vegetation will be an oligotrophic beech forest (Luzulo-Fagetum). The age of stands varies between 50 and 150 years. To specify tree species influence on site conditions and vegetation, the study also includes light climate and soil data of the stands. It is observed that, with regard to all comparisons, the admixture of beech reduces plant species diversity but increases naturalness of the stands. The intensity of beech admixture effects differs. While in Scots pine stands the impact of admixed beech is very noticeable, with the mixed stands being nearly identical with pure beech stands, the species change in Douglas-fir and Norway spruce stands proceeds more slowly. Assuming that the status in nature conservation and forest management is improving with increasing plant species diversity and increasing naturalness, the results of this study show a contrary development on a stand scale, as the potential natural vegetation of the Luzulo-Fagetumis in its self very species poor on vascular plants

>> Volltextversion (pdf 1.8 M; Heft 11-Aufsatz 5; Original paper; Language: English; urn:nbn:de:0041-afsv-01157)

LIESKE, B.: Selbstverständnis des russischen Naturschutzes und die Entwicklung der Sapowedniks – eine Interviewstudie

(The Way Russian Nature Conservationists See Themselves and Development of the Sapowedniks - an Interview Study)

Abstract
Nature conservation in Russia is facing a difficult situation at present. In 2000 the independent state-run Office of Environmental Care was abolished in actuality. The work of the environmental movement is being impeded by the state, and conservationists have to change their strategies in order to assert themselves against other interest groups. Russia's nature reserves occupy vast areas, particularly the traditional 'zapovedniki', most of which belong to the conservation category Ia of IUCN. Any human activity in the 'zapovedniki' is prohibited, with the exception of scientific research work. The system of nature reserves is facing a serious crisis due to the radical social changes of the past 20 years, the institutional guidelines and the continual low financing of research institutions. The nature reserves are greatly restricted as to their existence and function. Possibilities for preserving and further developing nature reserves in the Russian Federation as seen by competent Russian conservationists are looked at in detail. Observations on effectively supporting Russian nature conservation are made in conclusion. This article is based on an analysis of mainly Russian specialist literature and documents referring to Russian nature conservation covering a period of over 100 years. The current situation is studied by analysing expert interviews with ten Russian conservationists. This article is an excerpt from the diploma thesis by the author with the title „The Way Russian Nature Conservationists See Themselves and Development Prospects of the System of Nature Reserves" written at the Institute of Botany and Landscape Ecology at Greifswald University (march 2006 – november 2007). The issues of this article refer to the research of 2007. Of sure there are further literature and newer developments, which couldn't considered.

>> Volltextversion (pdf 1.4 M; Heft 11-Aufsatz 2; Original paper; Language: Deutsch; urn:nbn:de:0041-afsv-01122)