Restoration of plant populations and communities - insights from ecology and genetics for conservation

Biodiversity is defined as the variety of life on earth, comprising genetic diversity, species diversity and ecosystem diversity. It is crucial for human life since it is the foundation of functioning ecosystems, which provide necessary ecosystem services. In the past centuries, human activities have altered the world’s ecosystems and led to massive losses in biodiversity. To counteract the ongoing decrease in biological diversity therefore is a key issue in conservation. The reintroduction of native plant species is a common and useful practice in restoration and approaches range from reintroduction of plant populations to the creation of whole plant communities. Chapter One addresses the research question of this thesis and introduces the sci-entific context. The importance of biodiversity and its ongoing loss is described. Fur-ther, plant species reintroduction as an effective procedure to increase biodiversity on population and community level is presented with respect to the impact on genetic variation within restored populations and among natural and restored populations of herbaceous target species. Chapter Two focuses on the genetic diversity within and the genetic differentiation among populations of the rare and endemic plant species Cochlearia bavarica. Am-plified Fragment Length Polymorphisms (AFLP) were used to analyze the genetic variation of 32 remnant populations of the species. With respect to conservation management, recommendations are presented to increase the success of future population reintroduction and reinforcement. In Chapter Three the restoration of species-rich grassland communities by the transfer of green hay and threshed plant material was investigated. Species diversity and composition on restoration sites compared to their corresponding source sites was analyzed. Further genetic variation within and among populations on source and restoration sites of the common grassland species Knautia arvensis and Plantago lanceolata was examined using AFLPs. The study revealed no significant differences among source sites and their corresponding restoration sites, neither in species di-versity and composition nor in genetic variation within populations of the two plant species. Only marginal differences in genetic variation among populations on source sites and their corresponding restoration sites could be found. The transfer of local plant material is highly suited to preserve species composition of species-rich grass-lands and the natural genetic pattern of typical grassland plant species on a small geographical scale. Chapter Four and Five focus on the restoration of species-rich grassland communi-ties by sowing commercially produced regional seed mixtures. Even though this is a common approach in restoration ecology today, there are only few long-term studies investigating if local seed mixtures can actually be applied successfully to restore species-rich grassland communities. Further, it is often questioned whether commer-cially produced seed material is viable enough to establish vital populations and how the sowing may affect genetic variation of neighboring natural populations. Hence, the outcome of a large-scale grassland restoration project which started about 15 years ago in south-eastern Germany provides more information about the impact of this restoration measure on species diversity and genetic variation of plant species and populations on restored sites. The success of applying local seed mixtures to restore species-rich grasslands was analyzed within Chapter Four. Local seed mixtures can be used successfully to re-store species-rich grassland communities in practice: of all species that were present in the local seed mixtures 62 % were contained in the current and on average cov-ered up two thirds of the total vegetation cover. Moreover, restoration can be im-proved by using specific seed densities and species that are ecologically more suita-ble to restored sites. In Chapter Five deal with the impact of the restoration management on genetic vari-ation within and among restored and natural populations of typical grassland species. Genetic variation of three common plant species (K. arvensis, Silene vulgaris and P. lanceolata) was analyzed with AFLPs. The study revealed that using commercially produced seed mixtures in restoration caused no decease in genetic diversity within restored populations of common grassland species but did not match exactly the lo-cal genetic pattern of the study species. However, commercially produced seed ma-terial reflects the genetic potential of an entire seed transfer zone and provides seeds for the reestablishment of genetically viable populations. Finally, in Chapter Six the results of the four main chapters are reviewed in the con-text of nature conservation. Benefits and disadvantages of species (re)introductions are discussed. Recommendations are given to enhance the success of species reintroduction in restoration projects

Reintroduction of the endangered and endemic plant species Cochlearia bavarica -Implications from conservation genetics

Population reintroduction is a common practice in conservation, but often fails, also due to the effects of inbreeding or outbreeding depression. Cochlearia bavarica is a strongly endangered plant species endemic to Bavaria in Germany, constantly declining since the late 1980s. Therefore, population reintroduction is intended. In this study, we analyzed genetic diversity within and genetic differentiation between all 32 remnant populations of the species in Swabia and Upper Bavaria using amplified fragment length polymorphisms. Our aim was to increase reintroduction success by providing data to avoid negative effects of inbreeding and outbreeding and to preserve the natural genetic pattern of the species. Genetic diversity within populations was low but similar to other rare and endemic species and varied strongly between populations but did not depend on population size. Our analysis revealed a strong geographic pattern of genetic variation. Genetic differentiation was strongest between Swabia and Upper Bavaria and at the population level, whereas differentiation between subpopulations was comparatively low. Isolation by distance and genetic differentiation was stronger among populations from Upper Bavaria than from Swabia. From the results of our study, we derived recommendations for a successful reintroduction of the species. We suggest using rather genetically variable than large populations as reintroduction sources. Moreover, the exchange of plant material between Swabia and Upper Bavaria should be completely avoided. Within these regions, plant material from genetically similar populations should preferably be used for reintroduction, whereas the exchange among subpopulations seems to be possible without a negative impact on genetic variation due to natural gene flow

Restoration of species‐rich grasslands by transfer of local plant material and its impact on species diversity and genetic variation—Findings of a practical restoration project in southeastern Germany

Restoration of species-rich grasslands is a key issue of conservation. The transfer of seed-containing local plant material is a proven technique to restore species-rich grassland, since it potentially allows to establish genetically variable and locally adapted populations. In our study, we tested how the transfer of local plant material affected the species diversity and composition of restored grasslands and the genetic variation of the typical grassland plant species Knautia arvensis and Plantago lanceolata. For our study, we selected fifteen study sites in southeastern Germany. We analyzed species diversity and composition and used molecular markers to investigate genetic variation within and among populations of the study species from grasslands that served as source sites for restoration and grasslands, which were restored by transfer of green hay and threshed local plant material. The results revealed no significant differences in species diversity and composition between grasslands at source and restoration sites. Levels of genetic variation within populations of the study species Knautia arvensis and Plantago lanceolata were comparable at source and restoration sites and genetic variation among populations at source and their corresponding restoration sites were only marginal different. Our study suggests that the transfer of local plant material is a restoration approach highly suited to preserve the composition of species-rich grasslands and the natural genetic pattern of typical grassland plant species

Grassland restoration by local seed mixtures: New evidence from a practical 15‐year restoration study

Aim Local seed mixtures are frequently used to restore species-rich grasslands. However, it has hardly been tested whether local seed mixtures can actually be applied successfully in grassland restoration practice at larger scales and long-term. To close this gap, we report the results of a large-scale restoration study in which grasslands were restored about 15 years ago using different local seed mixtures. Location Bavaria, SE Germany. Methods To evaluate the efficacy of the local seed mixtures, we compared the species composition of seed mixtures and current vegetation. We then tested whether restoration success depends on site characteristics such as the size and shape (rectangle or stripe) of the grassland, restoration procedures such as topsoil removal, seed density and land use, or species habitat preferences for light, water and nutrients, and species life span (annual, perennial). Results n average, the current vegetation contained 62.4% of all species that were present in the local seed mixtures. Species from the local seed mixtures made up on average 69.1% of the total cover in the established vegetation, whereby the species composition of the local seed mixture and vegetation differed significantly from each other. The probability that a sown species would establish increased with seed density up to 300 seeds/m². Furthermore, habitat preferences significantly affected species establishment chances, with species requiring full illumination, dry and nutrient-poor soil being more successful during restoration, reflecting the high proportion of sites with topsoil removal prior to seeding in our study. Annual species had significantly lower establishment chances compared with their perennial counterparts. Conclusions Our study provides another piece of evidence that local seed mixtures can be applied successfully in large-scale grassland restoration projects. We provide several practical recommendations of how such practices can be further improved by using specific seed densities and creating new local seed mixtures using species that are ecologically more suitable to the restored sites

Restoration of grasslands using commercially produced seed mixtures: genetic variation within and among natural and restored populations of three common grassland species

The use of commercially produced seed material is a common practice in restoration. However, the impact of sowing on genetic variation of natural populations is still unclear. Aim of this study was, therefore, to test if genetic variation within and among populations restored with local seed material corresponds to the genetic variation of neighboring natural populations. We investigated each ten natural and restored populations of three common grassland species (Knautia arvensis, Silene vulgaris and Plantago lanceolata), situated in five study regions in southeastern Germany. Our study revealed significant genetic differentiation between natural and restored populations of the insect-pollinated K. arvensis and S. vulgaris although differentiation was much stronger for K. arvensis since most restored populations contained another ploidy level than natural populations. For the wind-pollinated P. lanceolata, genetic differentiation between natural and restored populations was comparable to the genetic differentiation between its natural populations. Genetic diversity within restored populations of each species was equivalent or even higher than within natural populations. Our study provides evidence that the local genetic structure especially of common insect-pollinated grassland species may be affected by the application of regional seed mixtures in restoration. Regional admixed provenancing in seed production is an important approach to preserve regional patterns and to provide seeds for the reestablishment of genetically variable populations. The method would however be an even more powerful tool in restoration when ploidy levels would be checked before seed production and seed transfer zones would be smaller

Parasites of sheep herding dogs in central Germany

This paper reports on endoparasite infections diagnosed in 2012 by standard coproscopical techniques and coproantigen Giardia ELISA in 165 dogs used for sheep herding in 36 farms in central Germany. The overall prevalence of dogs with evidence of endoparasite infections was 27.3% (95% CI 20.6-34.7). The most frequently identified faecal forms were those of ascarids (Toxocara, 6.7%; Toxascaris 3.6%), hookworms (5.5%) and taeniid cestodes (4.2%), followed by those of Trichuris whipworms (3.0%), Capillaria aerophila (1.8%), Angiostrongylus and Crenosoma lungworms (1.2% each) and Cystoisospora canis coccidians (0.6%). Molecular identification demonstrated the seven dogs shedding taeniid eggs positive for Taenia (T.) species tapeworms (five, T. hydatigena; one, T. ovis; one Taenia sp.). Screening of the faeces with the coproantigen ELISA revealed Giardia specific antigen in 5.5% of the samples. The majority of the dogs had evidence of single endoparasite infections (22.4%) while evidence for infection with two or three parasites concurrently was found in six (3.6%) and two (1.2%) of the dogs, respectively. Dogs ≤ 1 year (n = 19) were parasitized more frequently (p < 0.05) with overall gastrointestinal parasites (63.2% vs. 20.5%), ascarids (36.8% vs. 6.8%) and Giardia spp. (21.1% vs. 3.4%) than older dogs (n = 146). Dogs which had been wormed within six months of examination tested less frequently positive for gastrointestinal helminths compared to dogs not wormed (11.1% vs. 25.0%; p = 0.0567). In addition, ear swabs taken from 43 sheep dogs in 2012 were examined, and Otodectes cynotis mites were extracted from one dog. Identification of ectoparasites collected by full body search and combing from 113 sheep dogs in the years 2011 to 2013 revealed infestation of fleas and ticks (each up to five specimens per dog) on 13 and 108 dogs, respectively, with nine dogs carrying both fleas and ticks. Archaeopsylla erinacei, Ctenocephalides (C) canis, C. felis and Pulex irritans fleas were identified from one, three, two and eleven dogs, respectively. Dermacentor reticulatus, Ixodes (I.) hexagonus and I. ricinus ticks were isolated from 16, eight and 95 dogs, respectively