Widespread decline in Central European plant diversity across six decades

Abstract Based on plant occurrence data covering all parts of Germany, we investigated changes in the distribution of 2136 plant species between 1960 and 2017. We analyzed 29 million occurrence records over an area of ~350,000 km 2 on a 5 × 5 km grid using temporal and spatiotemporal models and accounting for sampling bias. Since the 1960s, more than 70% of investigated plant species showed declines in nationwide occurrence. Archaeophytes (species introduced before 1492) most strongly declined but also native plant species experienced severe declines. In contrast, neophytes (species introduced after 1492) increased in their nationwide occurrence but not homogeneously throughout the country. Our analysis suggests that the strongest declines in native species already happened in the 1960s–1980s, a time frame in which often few data exist. Increases in neophytic species were strongest in the 1990s and 2010s. Overall, the increase in neophytes did not compensate for the loss of other species, resulting in a decrease in mean grid cell species richness of −1.9% per decade. The decline in plant biodiversity is a widespread phenomenon occurring in different habitats and geographic regions. It is likely that this decline has major repercussions on ecosystem functioning and overall biodiversity, potentially with cascading effects across trophic levels. The approach used in this study is transferable to other large‐scale trend analyses using heterogeneous occurrence data

sMon - Trend analysis of German biodiversity data

Most biodiversity data are collected by volunteers organised in natural history societies or citizen science projects, often closely aligned with (sub )national agencies and local authorities. Data may be heterogeneous in space, time and quality. Here, we present first results of trend analyses of joint work with German natural history societies and state and national conservation agencies through the sMon synthesis project within iDiv. We combine and harmonize exemplary datasets of different taxa and habitats to evaluate the potentials and limits for analysing changes in the state of biodiversity in Germany. We show trend analyses of occupancy frequency data for 60 dragonfly, 42 grasshopper species and amphibia across 3 federal states 1980-2015, using Bayesian hierarchical trend analyses that build on occupancy detection models. Based on these insights and evaluation of citizen science programmes globally, we derive principles for good practice citizen science project design, data collection and archiving and explore methodologies that can deal with fragmented data of different spatio-temporal resolution and quality. This includes harnessing the potentials offered by modern technology. Combined with experiences of joint working of volunteer experts, agencies and academic scientists, this informs perspectives for future biodiversity monitoring programmes in Germany

Dark septate endophytes and arbuscular mycorrhizal fungi (Paris‐morphotype) affect the stable isotope composition of 'classically' non-mycorrhizal plants

The vast majority of terrestrial plants exchange nutrients with fungal partners forming different mycorrhizal types. The minority of plants considered as non-mycorrhizal, however, are not necessarily free of any fungi, but are frequently colonized by elusive fungal endophytes, such as dark septate endophytes (DSE) or fine root endophytes (FRE). While a functional role of FRE in improvement of nutrient gain was recently elucidated, the function of DSE is still in discussion and was here addressed for 36 plant species belonging to the families Equisetaceae, Cypereaceae and Caryophyllaceae. Molecular and microscopic staining approaches were conducted to verify the presence of DSE in the investigated species. Stable isotope natural abundances of the elements carbon, nitrogen, hydrogen and oxygen and total nitrogen concentrations were analyzed for the respective species of the target plant families and accompanying mycorrhizal and non-mycorrhizal (Brassicaceae) plant species. Staining approaches confirmed the presence of DSE in all investigated species within the families Equisetaceae, Cyperaceae and Caryophyllaceae. A co-colonization with Paris-type arbuscular mycorrhiza (AM) was occasionally found by staining and molecular approaches in species of the Equisetaceae. Species of the Equisetaceae, Cyperaceae and Caryophyllaceae were significantly 15N-enriched in comparison to accompanying plants. In addition, a significant 13C and 2H enrichment and increased total nitrogen concentrations were found for representatives of the Equisetaceae. The 15N-enrichment found here for representatives of Equisetaceae, Cyperaceae and Caryophyllaceae provides evidence for a functional role of the ubiquitous DSE fungi. DSE fungi obviously provide access to 15N-enriched soil organic compounds probably in exchange for organic carbon compounds from plant photosynthesis. As indicated by additional 13C- and 2H-enrichments, representatives of the Equisetaceae apparently gain simultaneously organic carbon compounds from their AM fungi of the Paris-morphotype. Thus, species of the Equisetaceae have to be considered as partially, or in case of the achlorophyllous fertile Equisetum arvense, as fully mycoheterotrophic at least in some stages of their life cycle. So far mostly underappreciated fungi classified as DSE are suggested to occupy an ecologically relevant role similar to mycorrhizae and the occurrence of simultaneous functions of DSE and AM fungi in Equisetaceae is proposed

Towards a methodical framework for comprehensively assessing forest multifunctionality

Funded by Deutsche Forschungsgemeinschaft. Grant Number: DFG FOR 891/1-3 National Natural Science Foundation of China. Grant Numbers: 30710103907, 30930005, 31170457, 31210103910 Swiss National Science Foundation (SNSF) Sino-German Centre for Research Promotion in Beijing. Grant Number: GZ 986Peer reviewedPublisher PD

A checklist for using Beals’ index with incomplete floristic monitoring data : reply to Christensen et al. (2021): Problems in using Beals’ index to detect species trends in incomplete floristic monitoring data

Christensen et al. criticized the application of Beals’ index of sociological favourability to adjust for incomplete species lists when comparing repeated surveys. Their main argument was that using Beals’ conditional occurrence probabilities would systematically underestimate biodiversity change compared to using observed frequencies. Although this might be the case for rare species, as we explicitly stated in our original publication, we here use a worked-out example to show that this criticism is unjustified for species that are sufficiently represented in the reference data set. In our opinion, the misconception derives from ignoring one of the key requirements for applying Beal's index, which is the use of a sufficiently large reference data set to derive a reliable co occurrence matrix. We here show how the predicted probability for the occurrence of a species depends on the size of the reference data set and give recommendations on the premises for applying Beals’ approach for monitoring purposes

Stretching the IR theoretical spectrum on Irish neutrality: a critical social constructivist framework

In a 2006 International Political Science Review article, entitled "Choosing to Go It Alone: Irish Neutrality in Theoretical and Comparative Perspective," Neal G. Jesse argues that Irish neutrality is best understood through a neoliberal rather than a neorealist international relations theory framework. This article posits an alternative "critical social constructivist" framework for understanding Irish neutrality. The first part of the article considers the differences between neoliberalism and social constructivism and argues why critical social constructivism's emphasis on beliefs, identity, and the agency of the public in foreign policy are key factors explaining Irish neutrality today. Using public opinion data, the second part of the article tests whether national identity, independence, ethnocentrism, attitudes to Northern Ireland, and efficacy are factors driving public support for Irish neutrality. The results show that public attitudes to Irish neutrality are structured along the dimensions of independence and identity, indicating empirical support for a critical social constructivist framework of understanding of Irish neutrality

Effective biodiversity monitoring needs a culture of integration

Despite conservation commitments, most countries still lack large-scale biodiversity monitoring programs to track progress toward agreed targets. Monitoring program design is frequently approached from a top-down, data-centric perspective that ignores the socio-cultural context of data collection. A rich landscape of people and organizations, with a diversity of motivations and expertise, independently engages in biodiversity monitoring. This diversity often leads to complementarity in activities across places, time periods, and taxa. In this Perspective, we propose a framework for aligning different efforts to realize large-scale biodiversity monitoring through a networked design of stakeholders, data, and biodiversity schemes. We emphasize the value of integrating independent biodiversity observations in conjunction with a backbone of structured core monitoring, thereby fostering broad ownership and resilience due to a strong partnership of science, society, policy, and individuals. Furthermore, we identify stakeholder-specific barriers and incentives to foster joint collaboration toward effective large-scale biodiversity monitoring

Toward a methodical framework for comprehensively assessing forest multifunctionality

Biodiversity-ecosystem functioning (BEF) research has extended its scope from communities that are short-lived or reshape their structure annually to structurally complex forest ecosystems. The establishment of tree diversity experiments poses specific methodological challenges for assessing the multiple functions provided by forest ecosystems. In particular, methodological inconsistencies and nonstandardized protocols impede the analysis of multifunctionality within, and comparability across the increasing number of tree diversity experiments. By providing an overview on key methods currently applied in one of the largest forest biodiversity experiments, we show how methods differing in scale and simplicity can be combined to retrieve consistent data allowing novel insights into forest ecosystem functioning. Furthermore, we discuss and develop recommendations for the integration and transferability of diverse methodical approaches to present and future forest biodiversity experiments. We identified four principles that should guide basic decisions concerning method selection for tree diversity experiments and forest BEF research: (1) method selection should be directed toward maximizing data density to increase the number of measured variables in each plot. (2) Methods should cover all relevant scales of the experiment to consider scale dependencies of biodiversity effects. (3) The same variable should be evaluated with the same method across space and time for adequate larger-scale and longer-time data analysis and to reduce errors due to changing measurement protocols. (4) Standardized, practical and rapid methods for assessing biodiversity and ecosystem functions should be promoted to increase comparability among forest BEF experiments. We demonstrate that currently available methods provide us with a sophisticated toolbox to improve a synergistic understanding of forest multifunctionality. However, these methods require further adjustment to the specific requirements of structurally complex and long-lived forest ecosystems. By applying methods connecting relevant scales, trophic levels, and above? and belowground ecosystem compartments, knowledge gain from large tree diversity experiments can be optimized

A Proposal for a Tool for Visualising Plant Changes in Germany

Content: Aim; Up to now 4 Workshops in Leipzig; Study in focus of this course project; Selected studies; sMon - a Synthesis Project of iDi