Mark O. Gessner
A5055925282- Freshwater macroinvertebrate diversity and ecology
- Soil and Water Nutrient Dynamics
- Fish Ecology and Management Studies
- Microbial Community Ecology and Physiology
- Hydrology and Watershed Management Studies
- Hydrology and Sediment Transport Processes
- Aquatic Ecosystems and Phytoplankton Dynamics
- Environmental DNA in Biodiversity Studies
- Ecology and Vegetation Dynamics Studies
- Marine and coastal ecosystems
- Species Distribution and Climate Change
- Aquatic Invertebrate Ecology and Behavior
- Forest Ecology and Biodiversity Studies
- Coastal wetland ecosystem dynamics
- Isotope Analysis in Ecology
- Plant Pathogens and Fungal Diseases
- Peatlands and Wetlands Ecology
- Mycorrhizal Fungi and Plant Interactions
- Genomics and Phylogenetic Studies
- Diatoms and Algae Research
- Protist diversity and phylogeny
- Environmental Toxicology and Ecotoxicology
- Land Use and Ecosystem Services
- Plant responses to elevated CO2
- Atmospheric and Environmental Gas Dynamics
Technische Universität Berlin
2016-2025
Leibniz Institute of Freshwater Ecology and Inland Fisheries
2016-2025
Berlin Brandenburg Institute of Advanced Biodiversity Research
2018-2025
Fraunhofer Institute for Production Systems and Design Technology
2014-2023
Berlin Center for Genomics in Biodiversity Research
2018-2023
National Center for Ecological Analysis and Synthesis
2021
Universidade Federal do Paraná
2021
Helmholtz Centre for Environmental Research
2021
Leibniz Centre for Agricultural Landscape Research
2021
Institut für Angewandte Gewässerökologie (Germany)
2016-2019
Linking species and ecosystems is currently one of the great challenges in ecology. To this end, we assess here contributions bacteria, fungi, detritivorous invertebrates (shredders) to leaf litter breakdown, a key ecosystem-level process. We enclosed alder (Alnus glutinosa) willow (Salix fragilis) leaves coarse-mesh bags (5 g dry mass), placed them stream during peak fall, retrieved periodically determine mass remaining biomass leaf-associated organisms. Shredder was derived from numbers...
Leaf litter breakdown, a critical ecosystem level process in streams and other aquatic environments , has been conceptualized using models borrowed from terrestrial systems. We argue that current views of the fresh waters need to be conceptually improved. Specifically, we think idea breakdown proceeds three distinct temporal stages (leaching, conditioning, fragmentation) over emphasized. Leaching, massive loss soluble leaf components within 24 h after immersion, is generally considered...
Breakdown of seven leaf species covering a broad range litter qualities (lignin: 7—31% dry mass; tannin: 0.0—6.7%; nitrogen: 0.5—2.6%; phosphorus: 0.017—0.094%) and dynamics fungal biomass reproductive activity were studied in softwater mountain stream. Litter breakdown proceeded at exponential rates k ranging from 0.0042 d — 1 (evergreen oak) to 0.0515 (ash). Fungal colonization was generally rapid, with the fungus—specific indicator molecule ergosterol increasing initially negligible...
Reading the Leaves Excess inputs of nutrients—a type pollution known as eutrophication—threatens biodiversity and water quality in rivers streams. Woodward et al. (p. 1438 ; see Perspective by Palmer Febria ) studied how one key ecosystem process—leaf-litter decomposition—responds to eutrophication across a large nutrient gradient 100 European Leaf breakdown was stimulated low moderate concentrations but inhibited at high rates loading.
Assessment of the condition ecosystems is a critical prerequisite for alleviating effects multiple anthropogenic stresses imposed on them. For stream ecosystems, multitude approaches has been proposed this purpose. However, they all rest assessment structural attributes, even though it generally recognized that adequate characterization requires information both structure (pattern) and function (process). Therefore, we propose complementary approach to based evaluating ecosystem-level...
Summary 1 Nitrogen and phosphorus supply influences the rate of litter decomposition nutrient dynamics during decomposition. Besides total amount N P available to decomposers, their relative (N : ratio) might be important, e.g. through an influence on composition activity microbial communities. 2 We carried out two experiments using laboratory microcosms test that (i) ratios (in either or environment) determine whether limits decomposition, (ii) ‘critical’ ratio between limitation depends...
Fourteen strains of aquatic hyphomycete species that are common on decaying leaves in running waters were grown liquid culture and analyzed for total ergosterol contents. Media included an aqueous extract from senescent alder leaves, a malt broth, glucose-mineral salt solution. Concentrations fungal mycelium ranged 2.3 to 11.5 mg/g dry mass. The overall average was 5.5 mg/g. Differences among both growth media highly significant but followed no systematic pattern. Stationary-phase had...
Recent experiments, mainly in terrestrial environments, have provided evidence of the functional importance biodiversity to ecosystem processes and properties. Compared systems, aquatic ecosystems are characterised by greater propagule material exchange, often steeper physical chemical gradients, more rapid biological and, marine higher metazoan phylogenetic diversity. These characteristics limit potential transfer conclusions derived from experiments whilst at same time provide...
Empirical studies investigating the role of species diversity in sustaining ecosystem processes have focused primarily on terrestrial plant and soil communities. Eighteen representative drawn from post-1999 literature specifically examined how changes biodiversity affect benthic processes. Results these small-scale, low-diversity manipulative indicate that effects (mostly synonymous with local richness) are highly variable over space time frequently depend specific biological traits or...
Ecology Letters (2011) 14: 289–294 Abstract The decomposition of plant litter is one the most important ecosystem processes in biosphere and particularly sensitive to climate warming. Aquatic ecosystems are well suited studying warming effects on because otherwise confounding influence moisture constant. By using a latitudinal temperature gradient an unprecedented global experiment streams, we found that will likely hasten microbial produce equivalent decline detritivore-mediated rates. As...
Abstract Global pressures on freshwater ecosystems are high and rising. Viewed primarily as a resource for humans, current practices of water use have led to catastrophic declines in species the degradation ecosystems, including their genetic functional diversity. Approximately three‐quarters world's inland wetlands been lost, one‐third 28 000 assessed International Union Conservation Nature (IUCN) Red List threatened with extinction, vertebrate populations undergoing that more rapid than...
Traces of life are nearly ubiquitous on Earth. However, a central unresolved question is whether these traces always indicate an active microbial community or whether, in extreme environments, such as hyperarid deserts, they instead reflect just dormant dead cells. Although biomass and diversity decrease with increasing aridity the Atacama Desert, we provide multiple lines evidence for presence at times metabolically active, one driest places We base this observation four major evidence: (i)...
Plant litter breakdown is a key ecological process in terrestrial and freshwater ecosystems. Streams rivers, particular, contribute substantially to global carbon fluxes. However, there little information available on the relative roles of different drivers plant fresh waters, particularly at large scales. We present global-scale study streams compare biotic, climatic other environmental factors rates. conducted an experiment 24 encompassing latitudes from 47.8° N 42.8° S, using mixtures...
An experiment in >1000 river and riparian sites found spatial patterns controls of carbon processing at the global scale.
Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals mobilisation substantial resources. While reasons are varied, investments in both research conservation lag far behind those terrestrial marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five areas, an effort to support informed stewardship biodiversity. The proposed agenda aims advance globally as critical step improving...