Molecular biogeochemistry of dissolved organic matter in the permafrost-influenced Lena Delta and the coastal Laptev Sea

Dissolved organic matter (DOM) is a ubiquitous complex mixture of organic compounds in aquatic systems. DOM is an important contributor to the global carbon cycle. The global inventory of permafrost carbon represents half of the global belowground soil carbon. The mobilization and degradation of this carbon pool would have critical implications in the Arctic. The ultra-complex mixture of organic compounds in DOM is a proxy of ecosystem metabolism and represents an imprint of past and ongoing biogeochemical processes. Ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and statistical analyses were performed on DOM samples obtained in various expeditions to the Lena Delta and Laptev Sea. The DOM composition, reactivity and properties in the permafrost-influenced Lena Delta and coastal Laptev Sea, Siberia were characterized. The systematics of the molecular DOM composition with respect to source of natural waters, reactivity during the Lena River - Laptev Sea transition, mobilization, mineralization and turnover of permafrost-derived DOM were addressed

SKAGEX The Skagerrak experiment

This report is a collection of technical reports with data from SKAGEX and presentations from the SKAGEX Workshop in Lysekil, Sweden, in November 1992

Forest landscapes and global change. New frontiers in management, conservation and restoration. Proceedings of the IUFRO Landscape Ecology Working Group International Conference

This volume contains the contributions of numerous participants at the IUFRO Landscape Ecology Working Group International Conference, which took place in Bragança, Portugal, from 21 to 24 of September 2010. The conference was dedicated to the theme Forest Landscapes and Global Change - New Frontiers in Management, Conservation and Restoration. The 128 papers included in this book follow the structure and topics of the conference. Sections 1 to 8 include papers relative to presentations in 18 thematic oral and two poster sessions. Section 9 is devoted to a wide-range of landscape ecology fields covered in the 12 symposia of the conference. The Proceedings of the IUFRO Landscape Ecology Working Group International Conference register the growth of scientific interest in forest landscape patterns and processes, and the recognition of the role of landscape ecology in the advancement of science and management, particularly within the context of emerging physical, social and political drivers of change, which influence forest systems and the services they provide. We believe that these papers, together with the presentations and debate which took place during the IUFRO Landscape Ecology Working Group International Conference – Bragança 2010, will definitively contribute to the advancement of landscape ecology and science in general. For their additional effort and commitment, we thank all the participants in the conference for leaving this record of their work, thoughts and science

Meiofauna Biodiversity and Ecology

Meiofauna are small organisms ranging 30–500 μm in body size, inhabiting marine sediments and other substrata all over the world, even the most extreme ones. We can find many different meiofaunal species in a very small handful of sediment, with the most varied and curious shapes, that share peculiar lifestyles, ecological relationships, and evolutionary traits. They contribute significantly to the processes and functioning of marine ecosystems, thanks to their high abundance and taxonomical diversity, fast turnover and metabolic rates. Some meiofaunal taxa have also revealed their considerable utility in the evaluation of the ecological quality of coastal marine sediments in accordance with European Directives. Therefore, understanding the distribution patterns of their biodiversity and identifying the factors that control it at a global level and in different types of habitats is of great importance. Due to their very small morphological characteristics utilized for the taxonomical identification of these taxa, the suite of necessary skills in taxonomy, and the general taxonomic crisis, many young scientists have been discouraged to tackle meiofauna systematics. The papers collected in this book, however, bring together important themes on the biology, taxonomy, systematics, and ecology of meiofauna, thanks to the contribution of researchers from around the world from the USA, Brazil, Costa Rica, Mexico, Cuba, Italy, Belgium, France, Denmark, Russia, Kuwait, Vietnam, and South Korea. This was certainly an additional opportunity to build a more solid network among experts in this field and contribute to increasing the visibility of these tiny organisms. A special thanks to Prof. Wonchoel Lee for the wonderful taxonomic drawings of the species described in this volume that contribute to make our cover unique

Meiofauna Biodiversity and Ecology

Sedimentary habitats cover the vast majority of the ocean floor and constitute the largest ecosystem on Earth. These systems supply fundamental services to human beings, such as food production and nutrient recycling. It is well known that meiofauna are an abundant and ubiquitous component of sediments, even though their biodiversity and importance in marine ecosystem functioning remain to be fully investigated. In this book, the meiofaunal biodiversity trends in marine habitats worldwide are documented, along with the collection of empirical evidence on their role in ecosystem services, such as the production, consumption, and decomposition of organic matter, and energy transfer to higher and lower trophic levels. Meiofaunal activities, like feeding and bioturbation, induce changes in several physico-chemical and biological properties of sediments, and might increase the resilience of the benthic ecosystem processes that are essential for the supply of ecosystem goods and services required by humans. As a key component of marine habitats, the taxonomical and functional aspects of the meiofaunal community are also used for the ecological assessment of the sediments’ quality status, providing important information on the anthropogenic impact of benthos

The role of visual adaptation in cichlid fish speciation

D. Shane Wright (1) , Ole Seehausen (2), Ton G.G. Groothuis (1), Martine E. Maan (1) (1) University of Groningen; GELIFES; EGDB(2) Department of Fish Ecology & Evolution, EAWAG Centre for Ecology, Evolution and Biogeochemistry, Kastanienbaum AND Institute of Ecology and Evolution, Aquatic Ecology, University of Bern.In less than 15,000 years, Lake Victoria cichlid fishes have radiated into as many as 500 different species. Ecological and sexual sel ection are thought to contribute to this ongoing speciation process, but genetic differentiation remains low. However, recent work in visual pigment genes, opsins, has shown more diversity. Unlike neighboring Lakes Malawi and Tanganyika, Lake Victoria is highly turbid, resulting in a long wavelength shift in the light spectrum with increasing depth, providing an environmental gradient for exploring divergent coevolution in sensory systems and colour signals via sensory drive. Pundamilia pundamila and Pundamilia nyererei are two sympatric species found at rocky islands across southern portions of Lake Victoria, differing in male colouration and the depth they reside. Previous work has shown species differentiation in colour discrimination, corresponding to divergent female preferences for conspecific male colouration. A mechanistic link between colour vision and preference would provide a rapid route to reproductive isolation between divergently adapting populations. This link is tested by experimental manip ulation of colour vision - raising both species and their hybrids under light conditions mimicking shallow and deep habitats. We quantify the expression of retinal opsins and test behaviours important for speciation: mate choice, habitat preference, and fo raging performance

Assessing the effect of temperate MPAs on elasmobranch communities

Global chondrichthyan (sharks, skates, rays and chimaeras) populations are experiencing alarming declines, driven by intense targeted and incidental extraction. Marine Protected Areas (MPAs) represent one potential solution, which has gained traction in recent years. When implemented effectively, MPAs demonstrate potential to rebuild populations and enable ecosystem recovery. However, their value as an elasmobranch conservation tool remains contested, particularly in temperate waters such as the UK. One essential component of MPA efficacy is the implementation of robust ecological monitoring regimes that allow species trajectories to be characterised and responded to, in real-time. However, several challenges, inherent to both elasmobranchs and temperate marine environments, currently impede adequate elasmobranch surveillance inside MPAs. This thesis addressed these two interlinked components of elasmobranch conservation by 1) exploring the drivers of temperate MPA success and 2) investigating opportunities for elasmobranch monitoring advancements. A literature review was conducted to explore the determinants of MPA success for temperate elasmobranch conservation. Meanwhile, novel monitoring opportunities presented by technological developments were explored, in relation to current method limitations. This was aided by an in-depth field study exploring the impact of Lyme Bay MPA on the elasmobranch community, using a 12-year BRUV dataset. Finally, a drifting pelagic BRUV was developed to address specific difficulties associated with surveying pelagic sharks and their wider food webs. This thesis found that MPAs exhibit potential to benefit temperate elasmobranchs, but their success varies vastly between contexts depending on a variety of social and biophysical factors. Furthermore, studying Lyme Bay MPA identified minimal robust evidence of benefits on the elasmobranch community, and these were mainly afforded to a small-bodied, fast-growing shark (Scyliorhinus canicula). Finally, the pelagic drifting BRUV failed to detect pelagic sharks, but demonstrated value for characterising spatial variation in the wider pelagic food web. Overall, this work indicates that temperate elasmobranch MPAs can represent an effective elasmobranch conservation tool when the necessary guardrails are in place. Furthermore, to guarantee comprehensive elasmobranch protection, MPA establishment should be supported by robust ecological monitoring and a wider network of target and limit-based conservation strategies

Plant Community Mediated Responses of Alpine Ecosystems to Anthropogenic Nitrogen Deposition

Human alteration of the nitrogen (N) cycle has resulted in a rapid increase in the availability of biologically active N. An unintended consequence of increased N availability is increased levels of N deposition into natural landscapes, including alpine ecosystems which are particularly susceptible to adverse environmental impacts. In my dissertation, I have examined alpine plant and soil responses to N deposition 1) across multiple spatial scales throughout the Southern Rocky Mountains, 2) among diverse plant communities associated with unique environmental conditions common in the alpine of this region, and 3) among ecosystem pools of N contributing to stabilization of N inputs within those communities. I used a gradient of N deposition in the southern Rocky Mountains to examine spatial variation in the responses of an alpine moist meadow to gradual changes in N deposition. I developed a response framework of expected ecosystem changes associated with increasing inputs, and found that plant metrics, such as tissue concentrations of nitrogen, were positively correlated with ambient N inputs. Soil biogeochemical responses to N were minimal along the gradient, suggesting that a reduction in N inputs may allow ecosystem recovery if plant feedbacks to N cycling are negligible. I next established a N fertilization study in three common plant communities to compare community responses to simulated N deposition and examined the applicability of the response framework throughout the alpine. I found that communities responded to inputs of N differently for both plant and soil responses, with the dry meadow community showing the strongest effects of N inputs and at the lowest levels of N input while the wet meadow community had few responses contributing to ecosystem change. Finally, I compared the fate of N inputs among ecosystem pools of N within alpine communities receiving elevated N. I found differences in N uptake among the communities, and that uptake increased with elevated N inputs. Even so, ecosystem uptake of N in plant and soil pools was very low (7-11%), supporting the conclusion that the alpine ecosystem does not retain N inputs and that increased N deposition is unlikely to be stabilized in the alpine