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.

Net CO2 and H2O fluxes of terrestrial ecosystems

Abstract: Using 139 flux studies, we addressed the variability of net ecosystem surface assimilation (Asmax), net ecosystem surface respiration (Rsmax), as well as net surface evapotranspiration (Esmax) among and within vegetation types. While forests and C3 crops, particularly in the northern hemisphere, have been preferentially investigated, information on tropical forests, C4 grasslands or wetlands is rather limited. Almost no data are available for disturbed sites. Despite large variations within a vegetation type, enclosure studies tended to give highest Asmax rates compared to micrometeorological techniques. Excluding enclosure studies, we tested the effect of stand age and leaf area index (LAI) on net ecosystem gas exchange. For grasslands, Asmax increased by 7 μmol m−2 s−1 per unit LAI, for C4 crops by 11 μmol m−2 s−1, and for coniferous forests by 0.9 μmol m−2 s−1 per unit LAI. In contrast, Asmax of broad-leaved forests and C3 crops as well as Rsmax stayed constant over a wide range of LAI. Asmax and Rsmax of forests were lowest in young stands ( 160 years) was within the same range as those of 30- to 80-year-old forests, and always higher than those of regenerating stands. Rsmax seemed to decrease with age. Asmax increased linearly with ecosystem surface conductance for all vegetation types (r2 = 0.65). Asmax of forests and grasslands was closely related to Esmax (r2 = 0.87), with a slope of 0.082 μmol CO2 m−2 s−1/mmol H2O m−2 s−1. The results clearly illustrated where gaps in our knowledge exist and how ecosystem properties affect the capacity of net ecosystem gas exchange.

A portable steady-state porometer for measuring the carbon dioxide and water vapour exchanges of leaves under natural conditions.

Abstract: A portable porometer is described for measuring the steady-state CO2 and H2O exchange rates of leaves under natural conditions. The porometer has an open gas exchange system which monitors the differences in concentrations of CO2 and H2O entering and leaving a cuvette which is clamped on or around leaves. The cuvette is designed to maintain ambient air temperature and humidity around the leaf. This instrument may also be used to determine CO2 response curves in the field. Examples of diurnal courses are presented for attached leaves of different species having high and low rates of CO2 exchange.

Plant Specialization to Environments of Different Resource Availability

Abstract: Plants exert a major control over ecosystem processes, because they are the organisms through which carbon and nutrients enter the biota, and because plant parameters strongly influence the fluxes through ecosystems. Plants operate under certain rules of cost and benefit under which they adjust their rates of resource acquisition and patterns of resource partitioning (Orians and Solbrig 1977; Schulze 1982; Bloom et al. 1985). Both acquisition and partitioning determine plant growth and biomass losses, which in turn influence the transfer of resources to other trophic levels of the ecosystem. Plants are specialized to the large variety of terrestrial habitat conditions by different plant life forms (Schulze 1982) or by variations in life histories, physiological specializations, and morphological or cytological modifications which determine the actual competition within the community (Grime 1977). Plants of a given species are capable only to a certain degree of using available resources, and, if resources are available beyond this range, the community shifts toward a different group of dominant species which in turn also alter the habitat by changing the availability of light, carbohydrates, and nutrients, and the fluxes of resources through the ecosystem.

Decreased Ribulose-1,5-Bisphosphate Carboxylase-Oxygenase in Transgenic Tobacco Transformed with Antisense Rbcs .6. Effect on Photosynthesis in Plants Grown at Different Irradiance

Abstract: Tobacco (Nicotiana tabacum L) plants transformed with ‘antisense’ rbcS to decrease the expression of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) have been used to investigate the contribution of Rubisco to the control of photosynthesis in plants growing at different irradiances Tobacco plants were grown in controlled-climate chambers under ambient CO2 at 20°C at 100, 300 and 750 μmol·m−2·s−1 irradiance, and at 28°C at 100, 300 and 1000 μmol·m−2·s−1 irradiance (i) Measurement of photosynthesis under ambient conditions showed that the flux control coefficient of Rubisco (C infRubisco supA ) was very low (001–003) at low growth irradiance, and still fairly low (024–027) at higher irradiance (ii) Short-term changes in the irradiance used to measure photosynthesis showed that C infRubisco supA increases as incident irradiance rises, (iii) When low-light (100 μmol·m−2·s−1)-grown plants are exposed to high (750–1000 μmol·m−2·s−1) irradiance, Rubisco is almost totally limiting for photosynthesis in wild types However, when high-light-grown leaves (750–1000 μmol·m−2·s−1) are suddenly exposed to high and saturating irradiance (1500–2000 μmol·m−2·s−1), C infRubisco supA remained relatively low (023–033), showing that in saturating light Rubisco only exerts partial control over the light-saturated rate of photosynthesis in “sun” leaves; apparently additional factors are co-limiting photosynthetic performance, (iv) Growth of plants at high irradiance led to a small decrease in the percentage of total protein found in the insoluble (thylakoid fraction), and a decrease of chlorophyll, relative to protein or structural leaf dry weight As a consequence of this change, high-irradiance-grown leaves illuminated at growth irradiance avoided an inbalance between the “light” reactions and Rubisco; this was shown by the low value of C infRubisco supA (see above) and by measurements showing that non-photochemical quenching was low, photochemical quenching high, and NADP-malate dehydrogenase activation was low at the growth irradiance In contrast, when a leaf adapted to low irradiance was illuminated at a higher irradiance, Rubisco exerted more control, non-photochemical quenching was higher, photochemical quenching was lower, and NADP-malate dehydrogenase activation was higher than in a leaf which had grown at that irradiance We conclude that changes in leaf composition allow the leaf to avoid a one-sided limitation by Rubisco and, hence, overexcitation and overreduction of the thylakoids in high-irradiance growth conditions, (v) ‘Antisense’ plants with less Rubisco contained a higher content of insoluble (thylakoid) protein and chlorophyll, compared to total protein or structural leaf dry weight They also showed a higher rate of photosynthesis than the wild type, when measured at an irradiance below that at which the plant had grown We propose that N-allocation in low light is not optimal in tobacco and that genetic manipulation to decrease Rubisco may, in some circumstances, increase photosynthetic performance in low light

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