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.

An evaluation of forest decline based on field observations focussed on Norway spruce, Picea abies

Abstract: Forest decline in Europe is centred around areas where air pollution is heaviest. Although statistical relations are still debatable at the stand level, they are a basis for the discussion of mechanisms by which air pollutants affect forest health. The aetiologies of different syndromes of decline are discussed. Exposure to large concentrations of gaseous pollutants appears to have short-term rather than long-lasting effects, whereas pathogens seem to be of only secondary importance. The deposition of sulphur and nitrogen (nitrate and ammonium) pollutants has significantly modified soil chemistry and plant nutrition. In acidic low-pH soils spruce roots, instead of utilising nitrate, preferentially take up ammonium which interferes with the uptake of other cations, notably magnesium. The nitrate remaining in soil solution, as a result of the preferential uptake of ammonium, is leached together with sulphate to groundwater, accelerating soil acidification and further decreasing the calcium and/or magnesium to aluminium ratios in soil solution. Soil solution chemistry affects root development, and thus water and nutrient uptake. Canopy uptake of nitrogen, especially of ammonium, which is additional to root uptake, may occur and appears to stimulate growth inciting a nitrogen to cation imbalance with the consequential production of decline symptoms.

Comparing the influence of site quality, stand age, fire and climate on aboveground tree production in Siberian Scots pine forests.

Abstract: Temporal patterns of stem and needle production and total aboveground net primary production (ANPP) were studied at the tree and stand level along four chronosequences of Siberian Scots pine (Pinus sylvestris L.) forests differing in site quality (poor lichen type or the more fertile Vaccinium type) and in frequency of surface fires (unburned, moderately burned (fire return interval of approximately 40 years), or heavily burned (fire return interval of approximately 25 years)). The maximum range of variability in aboveground production was quantified for: (1) possible long-term changes in site quality; (2) stand age; (3) non-stand-replacing, recurring surface fires; and (4) interannual climate variability. For (1) and (2), total ANPP was low in the lichen-type chronosequence, reached a maximum of 170 g C m(-2) year(-1) after 100 years and decreased to 100 g C m(-2) year(-1) in older stands. Maximum ANPP in the Vaccinium-type chronosequence was 340 g C m(-2) year(-1) and occurred earlier in the 53-year-old stand than in the other stands. Along the lichen-type chronosequences, peak ANPP was paralleled by maximum carbon allocation to stem growth. (3) In mature trees, damage by recurrent surface fires decreased stem growth by 17 +/- 19% over a 10-year period relative to pre-fire values. At longer timescales, ANPP was hardly affected by fire-related differences in mortality. (4) Needle- plus stem-NPP, reconstructed for a 3-year period, varied within a range of 15 g C m(-2) year(-1) in the lichen-type stands and 35 g C m(-2) year(-1) in the Vaccinium-type stands. For the same period, the coefficient of variance was higher for needle-NPP (20 +/- 10%) than for stem-NPP (12 +/- 7%). Needle- and stem-NPP did not covary in time. Most 30-year time series of stem-NPP at the tree level exhibited strong autocorrelation. In older trees, stem-NPP was positively correlated with growing season precipitation. Thus, the factors driving variability in ANPP ranked according to their maximum influence as: stand age (controlled by the frequency of stand-replacing fires) > site quality > growth depression because of surface fire damage approximately equal age-related reduction in ANPP > interannual variability approximately equal long-term effects of fire (stand density reduction). In lichen-type forests, we found that ANPP at the landscape level declined sharply when the interval between stand-replacing fires was less than 120 years, illustrating that fire strongly influences ANPP of boreal Scots pine forests.

Community assembly and biomass production in regularly and never weeded experimental grasslands.

Abstract: We studied the natural colonisation of new species in experimental grasslands varying in plant species richness (from 1 to 60) and plant functional group richness (from 1 to 4) in either regularly or never weeded subplots during the first 3 years after establishment Sown species established successfully, with no differences in species richness or their relative abundances between the regularly and never weeded subplots during the study period Aboveground biomass of sown species increased with increasing sown species richness in both treatments While a positive relationship between sown species richness and total aboveground biomass (including colonising species) existed in the 2nd year after sowing in the regularly and never weeded subplots, this positive relationship decayed in the 3rd year in the never weeded subplots because of a higher biomass of colonising species in species-poor mixtures Total aboveground biomass varied independently of total species richness 3 years after sowing in both treatments Jaccard similarity of coloniser species composition between regularly and never weeded subplots decreased from the 2nd to the 3rd year, indicating a divergence in coloniser species composition Coloniser immigration and turnover rates were higher in regularly weeded subplots, confirming that weeding counteracts species saturation and increases the chance that new colonisers would establish Although our study shows that low diversity plant communities are unstable and converge to higher levels of biodiversity, the effects of initially sown species on community composition persisted 3 years after sowing even when allowing for succession, suggesting that colonising species mainly filled empty niche space

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