Different landscape factors explain establishment and persistence of river red gum (Eucalyptus camaldulensis) in agricultural landscapes of southeast Queensland

Riparian and floodplain ecosystems in production landscapes are considerably degraded and under continued pressure from surrounding land use. However, little is known about how remnant ecosystems respond to land use and hydrological factors in small non-riverine wetlands. River red gum (Eucalyptus camaldulensis) is a dominant tree species within these scattered remnants, which provides critical ecological functions for the remaining biodiversity. In this study, we investigated how different life stages of E. camaldulensis responded to land use and hydrological variables in the Condamine catchment of south east Queensland. We used logistic regression to develop models for different life stages of E. camaldulensis in two regions with differing land use intensity histories. Broad regional differences and land use practices at smaller scales best explained differences in E. camaldulensis occurrence for younger life stages, while hydrology (groundwater and connectivity to rivers) and land use practices (dryland agriculture and grazing) best explained differences in older life stages. The results indicate that different factors are important in determining the establishment and persistence of E. camaldulensis and that land use practices at the regional scale are key factors in determining the establishment and potential future persistence of E. camaldulensis in floodplain wetlands

Weichholzauen-Entwicklung als Beitrag zum naturverträglichen Hochwasserschutz im Biosphärenreservat Mittelelbe

Die Gefährdung von Auen mit ihren typischen Vegetationsgesellschaften beruht vor allem auf dem Ausbau der Flüsse zu Wasserstraßen, einhergehend mit dem Bau von Dämmen, Staustufen, Deichen und Uferbefestigungen. Der Ausbau der Wasserstraßen hat weitreichende Konsequenzen für die Hydrodynamik des Flusses, die Geomorphologie und die hydrologischen Bedingungen in der Aue. Ein Lebensraumtypus, der dabei in besonderem Maße betroffen ist, sind die Weichholzauen. Während vor wenigen Jahrhunderten die Vorländer der Elbe noch größere Bestände von Weichholz- und Hartholzauen aufwiesen, ist das heutige Landschaftsbild vor allem durch extensiv genutzte Grünländer geprägt. Weichholzauenwälder sind als prioritär zu schützender, natürlicher Lebensraumtyp eingestuft und besitzen eine besondere Schutz- und Entwicklungsbedürftigkeit. Weichholzauenwälder bieten nicht nur Lebensraum für viele seltene Tier- und Pflanzenarten, sie beeinflussen auch den Nährstoffkreislauf innerhalb der Aue, haben einen wichtigen Einfluss auf die Wasserqualität und stabilisieren Ufer- und Vorlandbereiche. Zudem dienen sie als Retentionsraum und können damit zum Hochwasserschutz beitragen. Vor diesem Hintergrund förderte die Deutsche Bundesstiftung Umwelt (DBU) das interdisziplinäre Projekt „KoWeB – Konzept zur Weichholzauen- Entwicklung als Beitrag zum naturverträglichen Hochwasserschutz an Bundeswasserstraßen“ in der Laufzeit 2006 bis 2009. Das Ziel war die Entwicklung einer praxistauglichen Methode zur Identifizierung von Flächen zur Ansiedlung von Weichholzauen in Überschwemmungsgebieten unter Beachtung der ökologischen Kriterien und der Hochwasserneutralität

Characterization of 23 polymorphic SSR markers in Salix humboldtiana (Salicaceae) using next‐generation sequencing and cross‐amplification from related species

Premise of the study: We present a set of 23 polymorphic nuclear microsatellite loci, 18 of which are identified for the first time within the riparian species Salix humboldtiana (Salicaceae) using next‐generation sequencing. Methods and Results: To characterize the 23 loci, up to 60 individuals were sampled and genotyped at each locus. The number of alleles ranged from two to eight, with an average of 4.43 alleles per locus. The effective number of alleles ranged from 1.15 to 3.09 per locus, and allelic richness ranged from 2.00 to 7.73 alleles per locus. Conclusions: The new marker set will be used for future studies of genetic diversity and differentiation as well as for unraveling spatial genetic structures in S. humboldtiana populations in northern Patagonia, Argentina.EEA BarilocheFil: Bozzi, Jorge Alfredo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Liepelt, Sascha. University of Marburg. Faculty of Biology. Conservation Biology Group; AlemaniaFil: Ohneiser, Sebastian. University of Marburg. Faculty of Biology. Conservation Biology Group; AlemaniaFil: Gallo, Leonardo Ariel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leyer, Ilona. University of Marburg. Faculty of Biology. Conservation Biology Group; Alemania. University of Geisenheim. Institute of Botany, Plant Ecology and Nature Conservation; AlemaniaFil: Ziegenhagen, Birgit. University of Marburg. Faculty of Biology. Conservation Biology Group; AlemaniaFil: Mengel, Christina. University of Marburg. Faculty of Biology. Conservation Biology Group; Alemani

Effects of management on soil bacterial and fungal diversity (Shannon Index) of the upper soil layer in nine German vineyards in 2016

Nine experimental vineyards were sampled in the Rhein-Hesse area, Germany, in June 2016. Each vineyard exhibited four experimental plots with different soil management types (complete cover, herbal seed mixture cover, alternating tillage, and complete tillage). In two inter-rows of each vineyard, a pooled sample of eight soil cores of the upper soil layer (0-10 cm) was used for DNA extraction. The samples were analyzed using Illumina Sequencing by an external sequencing company. The resulting data were further processed to obtain a matrix of OTU and read counts for soil bacteria and soil fungi. Shannon Indices were calculated from these matrixes as metrics of bacterial and fungal diversity

Habitat distribution and population genetics of riparian Salix species in space and time – a restoration framework for softwood forests along the Elbe River

Riparian softwood forests belong to the most endangered vegetation types in Central Europe due to diverse river management measures (e.g. dyking, river training, etc.). As unmodified hydro-geomorphic processes along rivers are widely lacking, which are necessary to create competition-free establishment sites, natural regeneration of the respective species is almost absent. Hence, restoration measures are required but are a challenging task given species’ ecological requirements as well as the different interests of economy, society, and nature conservation. My thesis was conducted within the framework of a project to develop a concept for the establishment of riparian softwood forests combining ecological and flood protection issues along the Middle Elbe River. Main aims were to investigate ecological as well as population genetic aspects of riparian softwood forest species to deliver a basis for improving the success of restoration measures such as plantings. Five studies were conducted dealing with different aspects of riparian softwood forest restoration. In the first study the ecological relationships of distribution patterns of riparian softwood forests and hydrological variables were examined on the basis of habitat distribution models, which were developed for two softwood vegetation types as well as two age classes. They revealed that hydrological variables are significantly related to and substantially determine species distribution. Based on the observed ecological patterns advices are given for the selection of suitable planting sites. In the second study, an experimental approach, potential effects of competition and biomass loss on the regeneration capability of vegetative propagules, i.e. cuttings, of diverse riparian Salix species were tested. It revealed that cuttings, similarly as seedlings, are prone to competition mainly due to demands for light, indicating that competition should be eliminated during establishment phases to increase the success of planting measures. The additionally tested resprouting ability of the species disclosed vigorous growth capacities of all investigated floodplain species making them particularly suitable for restoration purposes. Since much debate exists on softwood forest restoration plantings from a flood protections point of view the third study was conducted to assess the effect of riparian softwood forest plantings on flooding risk combining habitat distribution models as well as a two-dimensional hydraulic-numerical model. With this approach we could demonstrate that it is possible to identify sites which meet the criteria of both ecological as well as hydraulic suitability. Hence, substantial potential for “safe” plantings can be expected in managed river-floodplain systems. The fourth study dealt with possible effects of climate change on habitat distribution of riparian softwood forest species. While current conditions still disclose large potential for softwood forest restoration, habitat projections based on climate change induced hydrological alterations point to a further loss of suitable habitat in the future. Great uncertainty in habitat availability for restoration measures due to substantial variability in hydrological projections exists. However, this uncertainty should be implemented into restoration management to preserve riparian softwood forests in the long term. While current natural population structures and dynamics of riparian softwood forest species warn about an extremely critical condition regarding the long-term persistence of these vegetation types, results of the fifth study, a genetic population analysis, are less alarming. Clonal patterns and genetic diversity of Salix viminalis as a model species were investigated as basis for the selection of suitable planting material. Though clonal structures were prevalent no dominance of single clones was detected. Levels of genetic diversity were generally high and no negative effects of floodplain or stand fragmentation on diversity levels were found. From the observed genetic patterns, advices for the selection of planting material are deduced. Overall, the results presented in this thesis deliver a sound basis for the restoration of riparian softwood forests based on reforestation. Given the restricted sustainability of these measures additionally other restoration approaches should be considered enabling the “re-dynamisation” of the floodplain and hence the self-preservation of riparian softwood forests

Effects of soil management on vegetation parameters, soil parameters, soil microbial diversity and soil functions in nine vineyards in Rhine-Hesse, Germany, studied from 2016-2017

We investigated the effects of soil management on plant diversity, vegetation cover, soil parameters, bacterial and fungal diversity, and soil functions (soil respiration and decomposition of two different substrates) using a balanced experimental design covering nine vineyards in Rhine-Hesse, Germany. In all vineyards, we applied four soil management types: complete cover, herbal seed mixture cover, alternating tillage, and complete tillage. Plots were installed in 2015. Data acquisition was done in 2016 and 2017, except for soil respiration, which was only measured in 2016. Plant diversity and vegetation cover were assessed in the field. Soil parameters (C and N, pH, P, K, Mg, Cu) were measured using standard methods. Soil bacterial and fungal diversity was assessed using DNA extraction and Illumina sequencing. The Shannon Diversity Index based on bacterial and fungal OTUs was used as a metric for diversity. Basal soil respiration rate was measured by oxygen consumption using a customized respirometer in the lab. Litter decomposition was measured in the field over a period of 90 days by using the Tea Bag Index method, which applies standardized tea types as organic material

Effects of soil management on vineyard inter-row vegetation cover and plant species richness in nine German vineyards, assessed in spring 2017

Vegetation cover and number of plant species were recorded in nine experimental vineyards in the Rhein-Hesse area, Germany. Each vineyard exhibited four experimental plots with different soil management types (complete cover, herbal seed mixture cover, alternating tillage, and complete tillage). Plant species as well as the total cover of vegetation was assessed visually by using a wooden frame of one square meter (0.5 x 2 m) in two neighboring inter-rows in each plot of each vineyard. The assessment was done in spring and autumn in two subsequent years (2016, 2017). The present table shows the data for the period 'spring 2017'

Effects of management on soil bacterial and fungal diversity (Shannon Index of the upper soil layer in nine German vineyards in 2017

Nine experimental vineyards were sampled in the Rhein-Hesse area, Germany, in June 2017. Each vineyard exhibited four experimental plots with different soil management types (complete cover, herbal seed mixture cover, alternating tillage, and complete tillage). In two inter-rows of each vineyard, a pooled sample of eight soil cores of the upper soil layer (0-10 cm) was used for DNA extraction. The samples were analyzed using Illumina Sequencing by an external sequencing company. The resulting data were further processed to obtain a matrix of OTU and read counts for soil bacteria and soil fungi. Shannon Indices were calculated from these matrixes as metrics of bacterial and fungal diversity

Effects of soil management on vineyard inter-row vegetation cover and plant species richness in nine German vineyards, assessed in autumn 2016

Vegetation cover and number of plant species were recorded in nine experimental vineyards in the Rhein-Hesse area, Germany. Each vineyard exhibited four experimental plots with different soil management types (complete cover, herbal seed mixture cover, alternating tillage, and complete tillage). Plant species as well as the total cover of vegetation was assessed visually by using a wooden frame of one square meter (0.5 x 2 m) in two neighboring inter-rows in each plot of each vineyard. The assessment was done in spring and autumn in two subsequent years (2016, 2017). The present table shows the data for the period 'autumn 2016'

Effects of soil management on microbial respiration in nine German vineyards in summer 2016

Soil microbial respiration was measured in nine experimental vineyards in the Rhein-Hesse area, Germany, in June 2016. Each vineyard exhibited 4 experimental plots with different soil management types (complete cover, herbal seed mixture cover, alternating tillage, and complete tillage). In each vineyard, eight soil samples of the upper soil layer (0-10 cm) were taken, two neighboring inter-rows per plot. Microbial soil respiration rates were obtained from a 4.5 g fresh soil sample from each inter-row moisturized to water saturation and measured with a customized micro-respirometer (Scheu 1992) for about 22 hours and reported as the average oxygen consumption per gram dry soil between measurement hours 10 - 20 h. The measurements were done at the University of Fribourg (Switzerland)