Dung fungi as an indicator of large herbivore dynamics in peatlands

This study was supported by the Ecological Continuity Trust and the Quaternary Research Association.Coprophilous fungal spores (CFS) have gained prominence in paleoecology as a proxy for large herbivore dynamics. Dung availability is one of several factors that influences spore abundance so it is unclear how closely CFS levels track herbivore biomass. This uncertainty is particularly relevant in peat- and moorland, where grazing impacts are a recurring topic in paleoecology and source of tension in environmental management, and where the method has yet to be tested. The current study used three ecological and conservation grazingexperiments in UK peat- and moorland to study modern and recent historic relationships between grazing treatment and the abundance of three key CFS types and three pollen disturbance indicators. A total of 78 surface samples and 2 short peat cores were analyzed. Dispersal distances are estimated to range from < 10m to tens of meters, based on significantly lower CFS abundance in exclosed than grazed plots at two sites, and similar CFS trends over the last century in short peats cores located 80m apart at the third site. The CFS signal thus represents activity in the surrounding landscape, despite predominantly local dispersal. CFS abundance does not correspond with animal biomass when compared across the three sites, however, and pollen disturbance indicators in the peat cores matched recent historic grazing records more consistently than CFS abundance. Potential reasons for these mismatches are discussed. Quantitative inferences about large herbivore abundance from CFS in peatlands should therefore be made with caution and recommendations are madefor further testing of the method.PostprintPeer reviewe

The application of resilience concepts in palaeoecology

The concept of resilience has become increasingly important in ecological and socio-ecological literature. With its focus on the temporal behaviour of ecosystems, palaeoecology has an important role to play in developing a scientific understanding of ecological resilience. We provide a critical review of the ways in which resilience is being addressed by palaeoecologists. We review ~180 papers, identifying the definitions or conceptualisations of ‘resilience’ that they use, and analysing the ways in which palaeoecology is contributing to our understanding of ecological resilience. We identify three key areas for further development. Firstly, the term ‘resilience’ is frequently defined too broadly to be meaningful without further qualification. In particular, palaeoecologists need to distinguish between ‘press’ vs. ‘pulse’ disturbances, and ‘ecological’ vs. ‘engineering’ resilience. Palaeoecologists are well placed to critically assess the extent to which these dichotomies apply in real (rather than theoretical) ecosystems, where climate and other environmental parameters are constantly changing. Secondly, defining a formal ‘response model’ - a statement of the anticipated relationships between proxies, disturbances and resilience properties - can help to clarify arguments, especially inferred causal links, since the difficulty of proving causation is a fundamental limitation of palaeoecology for understanding ecosystem drivers and responses. Thirdly, there is a need for critical analysis of the role of scale in ecosystem resilience. Different palaeoenvironmental proxies are differently able to address the various temporal and spatial scales of ecological change, and these limitations, as well as methodological constraints on inherently noisy proxy data, need to be explored and addressed.PostprintPeer reviewe

CMB observations from the CBI and VSA: A comparison of coincident maps and parameter estimation methods

We present coincident observations of the Cosmic Microwave Background (CMB) from the Very Small Array (VSA) and Cosmic Background Imager (CBI) telescopes. The consistency of the full datasets is tested in the map plane and the Fourier plane, prior to the usual compression of CMB data into flat bandpowers. Of the three mosaics observed by each group, two are found to be in excellent agreement. In the third mosaic, there is a 2 sigma discrepancy between the correlation of the data and the level expected from Monte Carlo simulations. This is shown to be consistent with increased phase calibration errors on VSA data during summer observations. We also consider the parameter estimation method of each group. The key difference is the use of the variance window function in place of the bandpower window function, an approximation used by the VSA group. A re-evaluation of the VSA parameter estimates, using bandpower windows, shows that the two methods yield consistent results.Comment: 10 pages, 6 figures. Final version. Accepted for publication in MNRA

Collaboration in natural resource governance: Reconciling stakeholder expectations in deer management in Scotland

The challenges of integrated, adaptive and ecosystem management are leading government agencies to adopt participatory modes of engagement. Collaborative governance is a form of participation in which stakeholders co-produce goals and strategies and share responsibilities and resources. We assess the potential and challenges of collaborative governance as a mechanism to provide an integrated, ecosystem approach to natural resource management, using red deer in Scotland as a case study. Collaborative Deer Management Groups offer a well-established example of a 'bridging organisation', intended to reduce costs and facilitate decision making and learning across institutions and scales. We examine who initiates collaborative processes and why, what roles different actors adopt and how these factors influence the outcomes, particularly at a time of changing values, management and legislative priorities. Our findings demonstrate the need for careful consideration of where and how shared responsibility might be best implemented and sustained as state agencies often remain key to the process, despite the partnership intention. Differing interpretations between agencies and landowners of the degree of autonomy and division of responsibilities involved in 'collaboration' can create tension, while the diversity of landowner priorities brings additional challenges for defining shared goals in red deer management and in other cases. Effective maintenance depends on appropriate role allocation and adoption of responsibilities, definition of convergent values and goals, and establishing communication and trust in institutional networks. Options that may help private stakeholders offset the costs of accepting responsibility for delivering public benefits need to be explicitly addressed to build capacity and support adaptation. This study indicates that collaborative governance has the potential to help reconcile statutory obligations with stakeholder empowerment. The potential of collaboration to reduce the costs of sustainable management remains contentious and, in times of increasing resource constraints, the potential mismatch between resource investment and anticipated goals is likely to become a critical issue, which may challenge the goals and capacity of the state and existing managers. (C) 2012 Elsevier Ltd. All rights reserved.</p

Pollen-based reconstruction reveals the impact of the onset of agriculture on plant functional trait composition

The onset of agriculture improved the capacity of ecosystems to produce food, but inadvertently altered other vital ecosystem functions. Plant traits play a central role in determining ecosystem properties, therefore we investigated how the onset of agriculture in Europe changed plant trait composition using 78 pollen records. Using a novel Bayesian approach for reconstructing plant trait composition from pollen records, we provide a robust method that can account for trait variability within pollen types. We estimate an overall four-fold decrease in plant size through agriculture and associated decreases in leaf and seed size. We show an increase in niche space towards the resource-acquisitive end of the leaf economic spectrum. Decreases in leaf phosphorus might have been caused by nutrient depletion through grazing and burning. Our results show that agriculture, from its start, has likely been gradually impacting biogeochemical cycles through altered vegetation composition

Davies-et-al-Supplementary – Supplemental material for The application of resilience concepts in palaeoecology

<p>Supplemental material, Davies-et-al-Supplementary for The application of resilience concepts in palaeoecology by Althea L Davies, Richard Streeter, Ian T Lawson, Katherine H Roucoux and William Hiles in The Holocene</p