Ernst Detlef Schulze

Bio: Ernst Detlef Schulze is an academic researcher from Max Planck Society. The author has contributed to research in topics: Biodiversity & Ecosystem. The author has an hindex of 133, co-authored 670 publications receiving 69504 citations. Previous affiliations of Ernst Detlef Schulze include University of Idaho & University of Utah.

Stable sulfur isotopes in forest spring waters from the Fichtelgebirge (Germany)

Abstract: The potential role of processes discriminating S isotopes, for example dissimilatory SO4 2- reduction and mineralization, in determining SO4 2- concentrations was studied in forest spring water. S-isotope composition of sulfate from atmospheric input and forest springs representing a wide range of SO4 2- concentrations was investigated in the Fichtelgebirge (NE Bavaria, Germany). δ34 S values in atmospheric input ranged from +3.7 to - 5.7‰. In spring waters with SO4 2- > 150 μmol 1−1 δ34 S values were between +4 and -5‰. whereas δ34 S values increased up to +7.2‰ below 150 μmol 1−1 SO4 2-. SO4 2- mineralization seemed to have no effect on isotopic composition since all δ34 S values of spring water were higher than input values. Dissimilatory SO4 2- reduction occurred in springs with SO4 2- < 150 μmol1−1. Spatial heterogeneity in forest soils or flow paths has to be invoked to explain increased δ34 S values since NO3 - concentrations would not allow for SO4 2- reduction to occur.

The climate mitigation potential of managed versus unmanaged spruce and beech forests in Central Europe

Abstract: The European Union (EU) has promised to cut its energy consumption by 20% by 2020. As a result, the use of petroleum products has continually decreased, and the use of renewable energy sources has increased. For the EU as a whole, however, the use of wood for energy has been fairly constant, even if its use has increased in several countries, for example, in the Nordic countries, the United Kingdom (UK), and Germany. As the consumption grows, the demands are increasingly met by imports of wood pellets, especially in countries with small forest areas such as Denmark and the UK, but also in Germany. Even if the forest area is increasing in many European countries, the land use change for urban development and nature conservation efforts have furthermore reduced the contribution of the forest sector in some countries. Given this situation, this chapter analyzed how managed and unmanaged temperate forests of the deciduous broad-leaved European beech (Fagus sylvatica) and the evergreen coniferous Norway spruce (Picea abies) species, to see how these forests can best help to mitigate climate change by storage of carbon in the forest and substitution of fossil intensive materials. The assessment was based on yield tables, wood assortment tables, deadwood and product-decay functions, and on the measured growth data from managed and unmanaged forests. All results are expressed as wood volume (m3/ha) that either store carbon or is made available for substitution through harvesting. The time frame is based on a suggested natural life cycle of unmanaged forest which is 230 years for beech and 350 years for spruce. In such time frames, the mitigation effect by storage is approximately zero for unmanaged forests, as the produced biomass is subject to natural mortality and input to deadwood pools that decompose and return the CO2 to the atmosphere. In unmanaged forests the mean volume stock over 350 years was 324±252 m3/ha for beech and 406±295 m3/ha for Norway spruce. For managed forests, there are, in the same time frame, also no or only minor storage effects in the long term, unless substantial changes take place in forest management or wood use. But it is also important to protect these stocks and the stocks of wood products, which together were 543 m3/ha for managed beech and 624 m3/ha for managed spruce, and of these, 279 and 342 m3/ha are stored in the forest, respectively. The forest management effect only becomes apparent through substitution effects for fossil intensive materials and the fossil fuels. In this context the role of wood energy and products is complex. Only some wood residues substitute the fossil energy and only some products substitute materials with high energy cost. Products are a transient pool of wood, which is feed by forest harvest, and which loses wood during processing and after consumption for energy or other use. The total supply of wood for energy is 1177 m3/ha over 230 years in beech (5.1 m3/ha/year) and of 3395 m3/ha over 350 years in spruce (9.7 m3/ha/year). Thus the contribution for climate change mitigation is larger for coniferous than for broadleaved species, and managed forests contribute more than unmanaged forests to storage. The implications of nature conservation, land use change are discussed, together with various options for improving incentives for forest management through international greenhouse gas accounting systems, which must still avoid double accounting.

Growth and Photosynthetic Carbon Metabolism in Tobacco Plants under an Oscillating CO2 Concentration in the Atmosphere

Abstract: The hypothesis for the present work was that photosynthetic acclimation to increased atmospheric CO2 in Nicotiana tabacum could be prevented by an oscillating supply of CO2. This was tested by growing half of the plants (for the 20 day period after sowing) at 700 μmol mol-1 CO2 (S+ plants) and half at 350 μmol mol-1 CO2 (S- plants) and thereafter switching them every 48 h from high to low CO2 and vice versa. These plants were compared with plants continuously kept (from sowing onwards) at 350 μmol mol-1 CO2 (C- plants) and 700 μmol mol-1 CO2 (C+ plants). Switching plants from high to low CO2 and vice versa (S+ and S-) did not improve plant growth efficiency, as hypothesized. The extra carbon fixed by the leaves under increased CO2 in the atmosphere, supplied either continuously or intermittently, was mostly stored as starch and not used to build additional structural biomass. The differences in final plant biomass, observed between S+ and S- plants, are explained by the CO2 concentration in the atmosphere during the first 20 days after sowing, the oscillation in CO2 supply thereafter is playing a smaller role in this response. Switching plants from high to low CO2 and vice versa, also did not prevent down-regulation of photosynthesis, despite lower leaf sugar concentrations than in C+ plants. Nitrate concentration decreased dramatically in C+, S+ and S- plants. The leaf C/N ratio was highest in C+ plants (ranging from 8 to 13), intermediate in S+ and S- plants (from 7 to 11) and lowest in C- plants (from 6 to 8). This supports the view that the balance between carbohydrates and nitrogen may have a triggering role in plant response under elevated CO2. Carbon export rates by the leaves seem to be independent of total carbon assimilation, suggesting a sink limiting effect on tobacco growth and phototsynthesis under elevated CO2.

Uncertainties of global biochemical predictions

Abstract: Publisher Summary In the past few years, application of improved measurements and models suggests a robust partitioning of CO 2 emissions from fossil fuel consumption and land use: about one-third remains in the atmosphere, one-third is reassimilated by land surfaces, and one-third is absorbed by the oceans. This chapter deals with the problems in locating a sink and emphasizes on the spatial, temporal, and biological variability of processes on local as well as continental scale. The commercial idea to market carbon sinks has initiated a major discussion about where on earth the largest sink capacity exists. It has been proposed that the sink exists in the Northern hemisphere with its center in the Eurasian region. This was countered and other theory propose based on analysis of gradients of CO 2 in the atmosphere that continental USA was the major carbon sink in the Northern hemisphere. On the other hand another theory predicts that the main terrestrial carbon sink is in the tropics. Current identification of biomes is not based on a functional analysis, and while some major biomes function similarly in carbon uptake (e.g., European conifer and deciduous forest) within-biome or-species effects can be extremely large. New ways of organizing ecological variability are needed. Further, the quantification of the mean residence time of vegetation and soil compartments and an understanding of the parameters that control this time-scale is necessary for process based predictions of carbon storage.

The Theory of Island Biogeography

Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

Effects of biodiversity on ecosystem functioning: a consensus of current knowledge

Abstract: Humans are altering the composition of biological communities through a variety of activities that increase rates of species invasions and species extinctions, at all scales, from local to global. These changes in components of the Earth's biodiversity cause concern for ethical and aesthetic reasons, but they also have a strong potential to alter ecosystem properties and the goods and services they provide to humanity. Ecological experiments, observations, and theoretical developments show that ecosystem properties depend greatly on biodiversity in terms of the functional characteristics of organisms present in the ecosystem and the distribution and abundance of those organisms over space and time. Species effects act in concert with the effects of climate, resource availability, and disturbance regimes in influencing ecosystem properties. Human activities can modify all of the above factors; here we focus on modification of these biotic controls. The scientific community has come to a broad consensus on many aspects of the re- lationship between biodiversity and ecosystem functioning, including many points relevant to management of ecosystems. Further progress will require integration of knowledge about biotic and abiotic controls on ecosystem properties, how ecological communities are struc- tured, and the forces driving species extinctions and invasions. To strengthen links to policy and management, we also need to integrate our ecological knowledge with understanding of the social and economic constraints of potential management practices. Understanding this complexity, while taking strong steps to minimize current losses of species, is necessary for responsible management of Earth's ecosystems and the diverse biota they contain.

Agricultural sustainability and intensive production practices

Abstract: A doubling in global food demand projected for the next 50 years poses huge challenges for the sustainability both of food production and of terrestrial and aquatic ecosystems and the services they provide to society. Agriculturalists are the principal managers of global useable lands and will shape, perhaps irreversibly, the surface of the Earth in the coming decades. New incentives and policies for ensuring the sustainability of agriculture and ecosystem services will be crucial if we are to meet the demands of improving yields without compromising environmental integrity or public health.

The worldwide leaf economics spectrum

Abstract: Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of nutrients and dry mass in leaves, and operates largely independently of growth form, plant functional type or biome. Categories along the spectrum would, in general, describe leaf economic variation at the global scale better than plant functional types, because functional types overlap substantially in their leaf traits. Overall, modulation of leaf traits and trait relationships by climate is surprisingly modest, although some striking and significant patterns can be seen. Reliable quantification of the leaf economics spectrum and its interaction with climate will prove valuable for modelling nutrient fluxes and vegetation boundaries under changing land-use and climate.

Carbon Isotope Discrimination and Photosynthesis

Abstract: We discuss the physical and enzymatic bases of carbone isotope discrimination during photosynthesis, noting how knowledge of discrimination can be used to provide additional insight into photosynthetic metabolism and the environmental influences on that process