Michael Mirtl

The next generation of site-based long-term ecological monitoring: Linking essential biodiversity variables and ecosystem integrity

Global change effects on biodiversity and human wellbeing call for improved long-term environmental data as a basis for science, policy and decision making, including increased interoperability, multifunctionality, and harmonization. Based on the example of two global initiatives, the International Long-Term Ecological Research (ILTER) network and the Group on Earth Observations Biodiversity Observation Network (GEO BON), we propose merging the frameworks behind these initiatives, namely ecosystem integrity and essential biodiversity variables, to serve as an improved guideline for future site-based long-term research and monitoring in terrestrial, freshwater and coastal ecosystems. We derive a list of specific recommendations of what and how to measure at a monitoring site and call for an integration of sites into co-located site networks across individual monitoring initiatives, and centered on ecosystems. This facilitates the generation of linked comprehensive ecosystem monitoring data, supports synergies in the use of costly infrastructures, fosters cross-initiative research and provides a template for collaboration beyond the ILTER and GEO BON communities.

Long‐term impacts of nitrogen and sulphur deposition on forest floor vegetation in the Northern limestone Alps, Austria

ABSTRACT Question: Are there effects of long-term deposition of airborne nitrogen and sulphur on the forest floor vegetation from permanent plots collected in 1993 compared to 2005. Location: Northern limestone Alps in Austria. Methods: Single species responses were analysed by correlating trends in cover-abundance values, as derived from marginal models, with Ellenberg indicator values. Changes in the species composition of plots were analysed by correlating changes in mean Ellenberg indicator values with the displacement of plots within a multidimensional scaling ordination. Results: Trends in single species abundance were positively correlated with indicator values of soil pH but were independent of nutrient availability. A general trend towards the homogenisation of vegetation, due to convergent time vectors of the relevés, became obvious. Oligotrophic sites previously situated at the distal ends of ordination axes shifted towards the centre since they were enriched by species preferring mesotrophic conditions. The bulk of plots with intermediate site conditions hardly showed any trends. A concomitant analysis demonstrated that temporal changes in species composition exceed the variation in cover abundance estimates among different field botanists. Conclusions: N deposition can lead to a homogenisation of forest floor vegetation. Larger limestone areas with diverse soil conditions, such as the Northern limestone Alps in Austria, as a whole are thus negatively affected by airborne N deposition. Nevertheless, the vegetation was at least as strongly affected by an increase of basiphilous species as a result of decreasing S deposition. Nomenclature: Adler et al. (1994).

Development of LTSER Platforms in LTER-Europe: Challenges and Experiences in Implementing Place-Based Long-Term Socio-ecological Research in Selected Regions

This chapter introduces place-based, Long-Term Socio-Ecological Research (LTSER) Platforms conceptually and in practice. LTER-Europe has put strong emphasis on utilising the data legacy and infrastructure of traditional LTER Sites for building LTSER Platforms. With their unique emphasis on socio-ecological research, LTSER Platforms add a new and important dimension to the four pillars of LTER-Europe’s science strategy (systems approach, process-oriented, long-term and site-based). In this chapter, we provide an overview of the regionalised or place-based LTSER concept, including experiences garnered from Platform models tested within LTER-Europe, and we discuss the current status of LTSER Platforms on the European continent. The experiences gathered in 6 years of practical work and development of regional socio-ecological profiles as conceptual frameworks in the Austrian Eisenwurzen LTSER Platform will be used to assess weaknesses and strengths of two implementation strategies (evolutionary vs. strategically managed) and to derive recommendations for the future. The chapter represents the close of the first substantive loop of LTSER research that began in 2003 from conceptualisation to implementation and, through the introspective analysis here, a reconsideration of the central concepts.

Introducing the Next Generation of Ecosystem Research in Europe: LTER-Europe’s Multi-Functional and Multi-Scale Approach

LTER-Europe is the umbrella network for Long-Term Ecosystem Research (LTER) and Long-Term Socio-Ecological Research (LTSER) in Europe. It forms part of the global LTER network (ILTER). Comprising 18 formal national member networks and five emerging ones LTER-Europe represents more than 400 LTER sites and 23 LTSER platforms. Besides this in-situ component LTER-Europe stands for a network of scientists, disciplines, institutions, data and metadata, and research projects. The Network of Excellence ALTER-Net (FP6) provided the frame for meeting the objective to integrate the highly fragmented European infrastructure with LTER potential across national and disciplinary boarders. LTER-Europe has become the terrestrial and aquatic component in the network of networks, currently organised by the ESFRI preparatory project LifeWatch. The interdisciplinary expertise represented by the ALTER-Net consortium allowed further development of the LTSER concept. LTSER platforms have been developed as multi-scale and multi-level infrastructure for investigating interactions of human and natural systems on the regional or sub-regional level. These hot spots of interdisciplinary research (IDR) and data sets are now complementing the first pillar of LTER-Europe’s network, the network of LTER sites. The character and functional niche of LTER-Europe is best described by four core characteristics, namely “in-situ, long-term, system and process”: LTER-Europe’s research is generating or using data gathered together with a maximum of other sources of knowledge at concrete locations in the long term. This allows for the detection and quantification of processes of ecosystems and socio-ecological systems, which determine the sustainable provision of ecosystem services. Summarising, LTER-Europe is a multi-functional network, but also a process structuring and optimising a distributed research infrastructure, catalysing the development of research projects meeting societal needs and helping to streamline and harmonise the entire sector on the institutional, national, European and global level.

Conceptualising Long-Term Socio-ecological Research (LTSER): Integrating the Social Dimension

In order to support the emerging network of long-term ecological research (LTER) sites across Europe, the European Union has launched ALTER-Net, a network aiming at lasting integration of long-term socio-economic, ecological and biodiversity research. Due to its high population density and long history of human habitation, however, Europe’s ecosystems are generally intensively used. Social and natural drivers are so inextricably intertwined that the notion of ‘socio-ecological’ systems is appropriate. Traditional natural science-based approaches are insufficient to understand these integrated systems, as they cannot adequately capture their relevant socio-economic dimensions. This is particularly relevant because the EU launched ALTER-Net has an explicit aim to support sustainability, a goal that requires integration of socio-economic and ecological dimensions. As such, LTER is challenged to significantly expand its focus from ecological to socio-ecological systems, thus transforming itself from LTER to long-term socio-ecological research or LTSER. In order to support this transformation, this chapter explores several approaches for conceptualising socio-economic dimensions of LTSER. It discusses how the socio-economic metabolism approach can be combined with theories of complex adaptive systems to generate heuristic models of society–nature interaction which can then be used to integrate concepts from the social sciences. In particular, the chapter discusses possible contributions from the fields of ecological anthropology and ecological economics and shows how participatory approaches can be integrated with innovative agent-based modelling concepts to arrive at an integrated representation of socio-ecological systems that can help to support local communities to move towards sustainability.

Genesis, goals and achievements of Long-Term Ecological Research at the global scale: A critical review of ILTER and future directions

Since its founding in 1993 the International Long-term Ecological Research Network (ILTER) has gone through pronounced development phases. The current network comprises 44 active member LTER networks representing 700 LTER Sites and ~80 LTSER Platforms across all continents, active in the fields of ecosystem, critical zone and socio-ecological research. The critical challenges and most important achievements of the initial phase have now become state-of-the-art in networking for excellent science. At the same time increasing integration, accelerating technology, networking of resources and a strong pull for more socially relevant scientific information have been modifying the mission and goals of ILTER. This article provides a critical review of ILTERs mission, goals, development and impacts. Major characteristics, tools, services, partnerships and selected examples of relative strengths relevant for advancing ILTER are presented. We elaborate on the tradeoffs between the needs of the scientific community and stakeholder expectations. The embedding of ILTER in an increasingly collaborative landscape of global environmental observation and ecological research networks and infrastructures is also reflected by developments of pioneering regional and national LTER networks such as SAEON in South Africa, CERN/CEOBEX in China, TERN in Australia or eLTER RI in Europe. The primary role of ILTER is currently seen as a mechanism to investigate ecosystem structure, function, and services in response to a wide range of environmental forcings using long-term, place-based research. We suggest four main fields of activities and advancements for the next decade through development/delivery of a: (1) Global multi-disciplinary community of researchers and research institutes; (2) Strategic global framework and strong partnerships in ecosystem observation and research; (3) Global Research Infrastructure (GRI); and (4) a scientific knowledge factory for societally relevant information on sustainable use of natural resources.

Establishment of a cross-European field site network in the ALARM project for assessing large-scale changes in biodiversity

The field site network (FSN) plays a central role in conducting joint research within all Assessing Large-scale Risks for biodiversity with tested Methods (ALARM) modules and provides a mechanism for integrating research on different topics in ALARM on the same site for measuring multiple impacts on biodiversity. The network covers most European climates and biogeographic regions, from Mediterranean through central European and boreal to subarctic. The project links databases with the European-wide field site network FSN, including geographic information system (GIS)-based information to characterise the test location for ALARM researchers for joint on-site research. Maps are provided in a standardised way and merged with other site-specific information. The application of GIS for these field sites and the information management promotes the use of the FSN for research and to disseminate the results. We conclude that ALARM FSN sites together with other research sites in Europe jointly could be used as a future backbone for research proposals.

Soil type affects migration pattern of airborne Pb and Cd under a spruce-beech forest of the UN-ECE integrated monitoring site Zöbelboden, Austria

Anthropogenic trace element emissions have declined. However, top soils all over the world remain enriched in trace elements. We investigated Pb and Cd migration in forest soils of a remote monitoring site in the Austrian limestone Alps between 1992 and 2004. Large spatial variability masked temporal changes in the mineral soil of Lithic Leptosols (Skeltic), whereas a significant reduction of Pb concentrations in their forest floors occurred. Reductions of concentrations in the less heterogeneous Cambisols (Chromic) were significant. In contrast, virtually no migration of Pb and Cd were found in Stagnosols due to their impeded drainage. Very low element concentrations (<1 microg l(-1)) in field-collected soil solutions using tension lysimeters (0.2 microm nylon filters) imply that migration largely occurred by preferential flow as particulate-bound species during intensive rainfall events. Our results indicate that the extent of Pb and Cd migration in soils is largely influenced by soil type.

Long-term environmental monitoring infrastructures in Europe: observations, measurements, scales, and socio-ecological representativeness

The challenges posed by climate and land use change are increasingly complex, with ever-increasing and accelerating impacts on the global environmental system. The establishment of an internationally harmonized, integrated, and long-term operated environmental monitoring infrastructure is one of the major challenges of modern environmental research. Increased efforts are currently being made in Europe to establish such a harmonized pan-European observation infrastructure, and the European network of Long-Term Ecological Research sites - LTER-Europe - is of particular importance. By evaluating 477 formally accredited LTER-Europe sites, this study gives an overview of the current distribution of these infrastructures and the present condition of long-term environmental research in Europe. We compiled information on long-term biotic and abiotic observations and measurements and examined the representativeness in terms of continental biogeographical and socio-ecological gradients. The results were used to identify gaps in both measurements and coverage of the aforementioned gradients. Furthermore, an overview of the current state of the LTER-Europe observation strategies is given. The latter forms the basis for investigating the comparability of existing LTER-Europe monitoring concepts both in terms of observational design as well as in terms of the scope of the environmental compartments, variables and properties covered.

Ecosytem Services: A Rapid Assessment Method Tested at 35 Sites of the LTER-Europe Network

Abstract The identification of parameters to monitor the ecosystem services delivered at a site is fundamental to the concept’s adoption as a useful policy instrument at local, national and international scales. In this paper we (i) describe the process of developing a rapid comprehensive ecosystem service assessment methodology and (ii) test the applicability of the protocol at 35 long-term research (LTER) sites across 14 countries in the LTER-Europe network (www.lter-europe.net) including marine, urban, agricultural, forest, desert and conservation sites. An assessment of probability of occurrence with estimated confidence score using 83 ecosystem service parameters was tested. The parameters were either specific services like food production or proxies such as human activities which were considered surrogates for cultural diversity and economic activity. This initial test of the ecosystem service parameter list revealed that the parameters tested were relatively easy to score by site managers with a high level of certainty (92% scored as either occurring or not occurring at the site with certainty of over 90%). Based on this assessment, we concluded that (i) this approach to operationalise the concept of ecosystem services is practical and applicable by many sectors of civil society as a first screen of the ecosystem services present at a site, (ii) this study has direct relevance to land management and policy decision makers as a transparent vehicle to focus testing scenarios and target data gathering, but (iii) further work beyond the scale investigated here is required to ensure global applicability.