Conditions promoting mycorrhizal parasitism are of minor importance for competitive interactions in two differentially mycotrophic species

Friede M, Unger S, Hellmann C, Beyschlag W. Conditions promoting mycorrhizal parasitism are of minor importance for competitive interactions in two differentially mycotrophic species. Frontiers in Plant Science. 2016;7: 1465.Interactions of plants with arbuscular mycorrhizal fungi (AMF) may range along a broad continuum from strong mutualism to parasitism, with mycorrhizal benefits received by the plant being determined by climatic and edaphic conditions affecting the balance between carbon costs vs. nutritional benefits. Thus, environmental conditions promoting either parasitism or mutualism can influence the mycorrhizal growth dependency (MGD) of a plant and in consequence may play an important role in plant-plant interactions. In a multifactorial field experiment we aimed at disentangling the effects of environmental and edaphic conditions, namely the availability of light, phosphorus and nitrogen, and the implications for competitive interactions between Hieracium pilosella and Corynephorus canescens for the outcome of the AMF symbiosis. Both species were planted in single, intraspecific and interspecific combinations using a target-neighbor approach with six treatments distributed along a gradient simulating conditions for the interaction between plants and AMF ranking from mutualistic to parasitic. Across all treatments we found mycorrhizal association of H. pilosella being consistently mutualistic, while pronounced parasitism was observed in C. canescens, indicating that environmental and edaphic conditions did not markedly affect the cost:benefit ratio of the mycorrhizal symbiosis in both species. Competitive interactions between both species were strongly affected by AMF, with the impact of AMF on competition being modulated by colonization. Biomass in both species was lowest when grown in interspecific competition, with colonization being increased in the less mycotrophic C. canescens, while decreased in the obligate mycotrophic H. pilosella. Although parasitism-promoting conditions negatively affected MGD in C. canescens, these effects were small as compared to growth decreases related to increased colonization levels in this species. Thus, the lack of plant control over mycorrhizal colonization was identified as a possible key factor for the outcome of competition, while environmental and edaphic conditions affecting the mutualism-parasitism continuum appeared to be of minor importance

Neues Klimaaggregat GK-0235 mit angeflanschter Küvette

Beyschlag W. Neues Klimaaggregat GK-0235 mit angeflanschter Küvette. Walz News. 1992;2:4-4

Canopy photosynthesis models - a valuable tool for ecological research

Beyschlag W. Canopy photosynthesis models - a valuable tool for ecological research. EcoSys (Suppl.). 1997;20:81-87

Vegetation Ecology of Dry Acidic Grasslands in the Temperate Zone

Jentsch A, Beyschlag W. Vegetation Ecology of Dry Acidic Grasslands in the Temperate Zone. Flora. 2003;198(1):3-25

Towards a causal analysis of stomatal patchiness: the role of stomatal size variability and hydrological heterogeneity

Beyschlag W, Eckstein J. Towards a causal analysis of stomatal patchiness: the role of stomatal size variability and hydrological heterogeneity. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY. 2001;22(3):161-173.The induction of the well known and widespread phenomenon 'stomatal patchiness' has been attributed to a variety of potential causes: from low PPFD levels, all kinds of stress conditions to CO2-changes and even fungal infections. A mechanism which explains the occurrence of reproducible patterns of static (i.e. stable) stomatal patchiness at low PPFD levels is proposed. Further, experimental evidence is presented for the hypothesis that dynamic (i.e. not stable) stomatal patchiness is a consequence of heterogeneous water status in different parts of the leaf and can be induced by all ambient factors which cause such heterogeneities. (C) 2001 Editions scientifiques et medicales Elsevier SAS

Benefits associated with steep foliage orientation in two tussock grasses of the American Intermountain West. A look at water-use-efficiency and photoinhibition

Ryel RJ, Beyschlag W. Benefits associated with steep foliage orientation in two tussock grasses of the American Intermountain West. A look at water-use-efficiency and photoinhibition. Flora. 1995;190:1-10

Photosynthetic performance and nutrient status of Norway spruce (Picea abies [L.] Karst. at forest sites of the Ore mountains (Erzgebirge)

Pfanz H, Beyschlag W. Photosynthetic performance and nutrient status of Norway spruce (Picea abies [L.] Karst. at forest sites of the Ore mountains (Erzgebirge). Trees, Struct. Funct. 1993;7:115-122

Ökophysiologie pflanzlicher Interaktionen Beiträge zur 3. Jahrestagung des Arbeitskreises "Experimentelle Ökologie der Pflanzen" in der GfÖ

Beyschlag W, Steinlein T, eds. Ökophysiologie pflanzlicher Interaktionen Beiträge zur 3. Jahrestagung des Arbeitskreises "Experimentelle Ökologie der Pflanzen" in der GfÖ. Bielefelder Ökologische Beiträge. Vol 14. Bielefeld; 1999

Gap Dynamics

Disturbance plays a significant role in the formation and persistence of plant communities. This ubiquitous and important process affects community succession (Shugart and West, 1980; Shugart 1984), composition (White, 1979), stability (van der Maarel, 1993; Lertzman, 1992) and biodiversity (Kohyama, 1993; Sole and Manrubia, 1995). Functioning as a process of canopy renewal, disturbance permits regeneration of species (Watt, 1947) shifts in species composition (Veblen, 1985) and spatial and temporal coexistence of species (Fox, 1977; Rebertus and Veblen, 1993). Within plant communities, disturbance refers to a disruption of portions of the community that changes resource availability (Pickett and White, 1985). Often, disturbance manifests itself in the plant community as a gap or patch, where foliage or even whole plants are removed or die. Typically, the resulting gaps are characterised by a difference in the level of light penetration from that of the surrounding vegetation but other environmental conditions can also be altered. Canopy gap formation and subsequent recovery can be the predominant process in plant community dynamics (van der Maarel, 1996). This chapter considers canopy turnover in the context of canopy gap dynamics and the response of plants to these transient spatial opportunities. A presentation of dynamic gap models follows the discussion, with reference to their utility in assessing community dynamics and climatic changes in forests

A Graphical User Interface for R in a Rich Client Platform for Ecological Modeling

Austenfeld M, Beyschlag W. A Graphical User Interface for R in a Rich Client Platform for Ecological Modeling. Journal of Statistical Software. 2012;49(4):1-19.For many ecological analyses powerful statistical tools are required for a profound analysis of spatial and time based data sets. In order to avoid many common errors of analysis and data acquisition a graphical user interface can help to focus on the task of the analysis and minimize the time to fulfill certain tasks in a programming language like R. In this paper we present a graphical user interface for R embedded in the ecological modeling software Bio7 which is based on an Eclipse rich client platform. We demonstrate that within the Bio7 platform R can not only be effectively combined with Java but also with the powerful components of Eclipse. Additionally we present some custom Bio7 components which interact with R and make use of some useful advanced concepts and libraries of this connection. Our overview on the Bio7 R interface also emphasizes a broad applicability for disciplines beyond ecological modelling