The challenges of integrating biodiversity and ecosystem services monitoring and evaluation at a landscape-scale wetland restoration project in the UK

There is an increasing emphasis on the restoration of ecosystem services as well as of biodiversity, especially where restoration projects are planned at a landscape-scale. This increase in the diversity of restoration aims has a number of conceptual and practical implications for the way that restoration projects are monitored and evaluated. Landscape-scale projects require monitoring of not only ecosystem services and biodiversity but also of ecosystem processes since these can underpin both. Using the experiences gained at a landscape-scale wetland restoration project in the UK we discuss a number of issues that need to be considered, including the choice of metrics for monitoring ecosystem services and the difficulties of assessing the interactions between ecosystem processes, biodiversity and ecosystem services. Particular challenges that we identify, using two pilot data sets, include the de-coupling of monetary metrics used for monitoring ecosystem services from biophysical change on the ground and the wide range of factors external to a project that influence the monitoring results. We highlight the fact that the wide range of metrics necessary to evaluate the ecosystem service, ecosystem process and biodiversity outcomes of landscape-scale projects presents a number of practical challenges including: the need for high levels of varied expertise, high costs, incommensurate monitoring outputs and the need for careful management of monitoring results especially where they may be used in making decisions about the relative importance of project aims.This research is linked to grants EN 06-2151 and 09-2739 from the Esmée Fairbairn Foundation.This is the author accepted manuscript. The final version is available from Ecology and Society via https://doi.org//10.5751/ES-08616-21031

The influence of hydrological regimes on sex ratios and spatial segregation of the sexes in two dioecious riparian shrub species in northern Sweden

River management practices have altered the hydrological regimes of many rivers and also altered the availability of regeneration niches for riparian species. We investigated the impact of changed hydrological regimes on the sex ratios and the Spatial Segregation of the Sexes (SSS) in the dioecious species Salix myrsinifolia Salisb.–phylicifolia L. and S. lapponum L. by studying the free-flowing Vindel River and the regulated Ume River in northern Sweden. We surveyed sex ratios of these species in 12 river reaches on the Vindel River and in 17 reaches on the Ume River. In addition, we surveyed the sex and location above mean river stage of 1,002 individuals across both river systems to investigate the SSS of both species. Cuttings were collected from male and female individuals of S. myrsinifolia–phylicifolia from both rivers and subjected to four different water table regimes in a greenhouse experiment to investigate growth response between the sexes. We found an M/F sex ratio in both river systems similar to the regional norm of 0.62 for S. myrsinifolia–phylicifolia and of 0.42 for S. lapponum. We found no evidence of SSS in either the free-flowing Vindel River or the regulated Ume River. In the greenhouse experiment, hydrological regime had a significant effect on shoot and root dry weight and on root length. Significantly higher shoot dry weights were found in females than in males and significantly different shoot and root dry weights were found between cuttings taken from the two rivers. We concluded that changed hydrological regimes are likely to alter dimensions of the regeneration niche and therefore to influence sex ratios and SSS at an early successional stage, making it difficult to find clear spatial patterns once these species reach maturity and can be sexed

Quantifying soil hydrology to explain the development of vegetation at an ex-arable wetland restoration site

Wetland restoration frequently sets well-defined vegetation targets, but where restoration occurs on highly degraded land such targets are not practical and setting looser targets may be more appropriate. Where this more ‘open-ended’ approach to restoration is adopted, surveillance methods that can track developing wetland habitats need to be established. Water regime and soil structure are known to influence the distribution and composition of developing wetland vegetation, and may be quantified using Sum Exceedence Values (SEV), calculated using the position of the water table and knowledge of soil stress thresholds. Use of SEV to explain patterns in naturally colonizing vegetation on restored, ex-arable land was tested at Wicken Fen (UK). Analysis of values from ten locations showed that soil structure was highly heterogeneous. Five locations had shallow aeration stress thresholds and so had the potential to support diverse wetland assemblages. Deep aeration stress thresholds at other locations precluded the establishment of a diverse wetland flora, but identified areas where species-poor wetland assemblages may develop. SEV was found to be a useful tool for the surveillance of sites where restoration targets are not specified in detail at the outset and may help predict likely habitat outcomes at sites using an open-ended restoration approach

Analyzing the Impacts of Dams on Riparian Ecosystems: A Review of Research Strategies and Their Relevance to the Snake River Through Hells Canyon

River damming provides a dominant human impact on river environments worldwide, and while local impacts of reservoir flooding are immediate, subsequent ecological impacts downstream can be extensive. In this article, we assess seven research strategies for analyzing the impacts of dams and river flow regulation on riparian ecosystems. These include spatial comparisons of (1) upstream versus downstream reaches, (2) progressive downstream patterns, or (3) the dammed river versus an adjacent free-flowing or differently regulated river(s). Temporal comparisons consider (4) pre- versus post-dam, or (5) sequential post-dam conditions. However, spatial comparisons are complicated by the fact that dams are not randomly located, and temporal comparisons are commonly limited by sparse historic information. As a result, comparative approaches are often correlative and vulnerable to confounding factors. To complement these analyses, (6) flow or sediment modifications can be implemented to test causal associations. Finally, (7) process-based modeling represents a predictive approach incorporating hydrogeomorphic processes and their biological consequences. In a case study of Hells Canyon, the upstream versus downstream comparison is confounded by a dramatic geomorphic transition. Comparison of the multiple reaches below the dams should be useful, and the comparison of Snake River with the adjacent free-flowing Salmon River may provide the strongest spatial comparison. A pre- versus post-dam comparison would provide the most direct study approach, but pre-dam information is limited to historic reports and archival photographs. We conclude that multiple study approaches are essential to provide confident interpretations of ecological impacts downstream from dams, and propose a comprehensive study for Hells Canyon that integrates multiple research strategies

River Restoration in Spain: Theoretical and Practical Approach in the Context of the European Water Framework Directive.

River restoration is becoming a priority in many countries because of increasing the awareness of environmental degradation. In Europe, the EU Water Framework Directive (WFD) has significantly reinforced river restoration, encouraging the improvement of ecological status for water bodies. To fulfill the WFD requirements, the Spanish Ministry of the Environment developed in 2006 a National Strategy for River Restoration whose design and implementation are described in this paper. At the same time many restoration projects have been conducted, and sixty of them have been evaluated in terms of stated objectives and pressures and implemented restoration measures. Riparian vegetation enhancement, weir removal and fish passes were the most frequently implemented restoration measures, although the greatest pressures came from hydrologic alteration caused by flow regulation for irrigation purposes. Water deficits in quantity and quality associated with uncontrolled water demands seriously affect Mediterranean rivers and represent the main constraint to achieving good ecological status of Spanish rivers, most of them intensively regulated. Proper environmental allocation of in-stream flows would need deep restrictions in agricultural water use which seem to be of very difficult social acceptance. This situation highlights the need to integrate land-use and rural development policies with water resources and river management, and identifies additional difficulties in achieving the WFD objectives and good ecological status of rivers in Mediterranean countries

Stating mechanisms and refining criteria for ecologically successful river restoration: a comment on Palmer et al. (2005)

1. To encourage more project assessment and reporting of restoration outcomes, Palmer et al. (2005) propose five criteria for assessing the ecological success of river restoration. They also suggest that these criteria should help to clarify which activities should qualify for ecological restoration funding and facilitate consistency about what constitutes an ecologically successful restoration project. 2. We critique the five criteria and agree they all merit inclusion in an assessment of successful river restoration. However, the practical application of measuring self-sustainability (resilience) following restoration is potentially problematic and an explicit timeframe is needed to evaluate the results of the restoration. 3. A sixth criterion is proposed that encourages specific hypotheses and/or a conceptual model of the ecological mechanisms by which the proposed activities will achieve their target. This would enhance our understanding of the mechanisms at play for successful river restoration, and provide a more powerful deductive framework likely to lead to appropriate practices that can be applied across rivers. To explore the potential practical applicability of these six criteria, we applied them to a recently published example of river restoration to ascertain its ecological success. 4. Synthesis and applications. We agree with the criteria proposed by Palmer et al. (2005), although the problems of measuring resilience and defining a timeline for recovery should be addressed. We suggest strengthening the deductive framework of restoration projects by formulating some sort of conceptual model. This step could involve scientists, and be a useful way of involving science more explicitly in restoration activities. Agreed-upon criteria for successful restoration will greatly facilitate evaluation of river ecosystem recovery at the critical broader scales where our knowledge is still limited

The economic consequences of conserving or restoring sites for nature

Nature provides many benefits for people, yet there are few data on how changes at individual sites impact the net value of ecosystem service provision. A 2002 review found only five analyses comparing the net economic benefits of conserving nature versus pursuing an alternative, more intensive human use. Here we revisit this crucial comparison, synthesising recent data from 62 sites worldwide. In 24 cases with economic estimates of services, conservation or restoration benefits (e.g. greenhouse gas regulation, flood protection) tend to outweigh those private benefits (e.g. profits from agriculture or logging) driving change to the alternative state. Net benefits rise rapidly with increasing social cost of carbon. Qualitative data from all 62 sites suggest that monetisation of additional services would further increase the difference. Although conservation and restoration did not universally provide greater net value than the alternative state, across a large, geographically and contextually diverse sample, our findings indicate that at current levels of habitat conversion, conserving and restoring sites typically benefits human prosperity.We thank Ben Balmford, Katie Bolt and James Vause for advice. AB was supported by a Royal Society Wolfson Merit award. KSHP was supported by an AXA Research Fund (Grant no. RG64520), while at the University of Cambridge