Do restoration measures rehabilitate fauna diversity in raised bogs? A comparative study on aquatic macroinvertebrates

To assess whether raised bog restorationmeasures contribute to the conservation andrestoration of the fauna diversity,macroinvertebrate species assemblages werecompared between water bodies created byrewetting measures and water bodies whichhave not been subject to restorationmeasures, but are remnants offormer peat cuttings and trenches used forbuckwheat culture in the past.The restoration sites were inhabited bycharacteristic raised bog species and rarespecies, but their numbers were higher atthe remnant sites not affected byrestoration management. A considerablenumber of characteristic and rare faunaspecies were only found at the remnantsites. The remnant sites includedconsiderably more variation inmacroinvertebrate species assemblages andhad a higher cumulative species richness.The number of characteristicmacroinvertebrate species was not clearlyrelated to the presence of a characteristicraised bog vegetation. In restoration sitesnumbers of rare and characteristic speciesper site tended to increase with the timeelapsed after rewetting. However,restoration measures will not automaticallyresult in restoration of a more or lesscomplete macroinvertebrate speciesspectrum, as restoration measures have sofar resulted in habitats for only a limitednumber of the characteristic species.When planning restoration measures, it isrecommended to protect the populations ofrare and characteristic species present inthe area, as these populations may becomethe sources for colonization of rewettedsites. Safeguarding habitat diversityduring the restoration process andrestoration of different elements of thehabitat diversity of complete raised bogsystems will result in the characteristicfauna diversity being conserved andrestored more successfully.     

Rehabilitation of industrial cutaway Atlantic blanket bog in County Mayo,North-West Ireland

Bord na Móna (the Irish PeatDevelopment Corporation) began peatextraction at Bellacorick, in County Mayo,in the north-west of Ireland in 1961. Thepeat production area comprised 8000 ha ofAtlantic blanket bog. To date, about 25%of the area has been taken out ofproduction as the peat resources wereexhausted. The cutaway landscape isheterogeneous, with some intact bogremnants among gravel hills bared throughpeat erosion, shallow acid highly-humifiedpeat deposits overlying relatively levelglacial till, and occasional pockets ofmineral-enriched peat in depressions. Theaims of the work described here are (a) toprovide a baseline vegetation survey of thecutaway, (b) to test potential managementtools for accelerating re-vegetation, and(c) to promote the re-establishment ofpeatland characteristics where possible.Thirteen plant communities were recorded onthe cutaway bog at Bellacorick. Extensiveareas of cutaway are colonised by Juncus effusus. Peatland communities havedeveloped where the drainage of cutaway hasbeen impeded and the water-table remains ator above the surface. Remnants of intactAtlantic blanket bog within the productionarea provide a local source of propagulesfor colonisation of adjacent bare cutaway.They also constitute locations for plantswith restricted distributions within theproduction area.Experimental plots were used to show thepositive impacts of (a) re-wetting ofcutaway surfaces in promoting thecolonisation and spread of Sphagnum,and (b) ridging of exposed gravel till thatprovides waterlogged and sheltered furrowsin which accelerated plant colonisationtakes place.A management plan is currently beingdevised for the rehabilitation of theBellacorick cutaway. Bog remnants should bemaintained as an essential part ofrehabilitation management. Rehabilitationwill include restoration of peat-formingconditions facilitated by waterlogging,which has been shown in experimental trialsto be enhanced by dam construction,infilling of drains and surface ridging. AtBellacorick, it is evident that, with time,peat-forming conditions can be restoredwith minimal management and economic cost.     

Seasonal Net Ecosystem Carbon Exchange of a Regenerating Cutaway Bog: How Long Does it Take to Restore the C‐Sequestration Function?

We measured the net ecosystem exchange (NEE) and respiration rates and modeled the photosynthesis and respiration dynamics in a cutover bog in the Swiss Jura Mountains during one growing season at three stages of regeneration (29, 42, and 51 years after peat cutting; coded sites A, B, and C) to determine if reestablishment of Sphagnum suffices to restore the C‐sequestration function. From the younger to the older stage Sphagnum cover increased, while net primary Sphagnum production over the growing season decreased (139, 82, and, 67 g m^?2 y^?1 for A, B, and C respectively), and fen plant species were replaced by bog species. According to our NEE estimations, over the vegetation period site A was a net CO₂‐C source emitting 40 g CO₂‐C/m² while sites B and C were accumulating CO₂‐C, on average 222 and 209 g CO₂‐C/m², respectively. These differences are due to the higher respiration in site A during the summer, suggesting that early regeneration stages may be more sensitive to a warmer climate. Methane fluxes increased from site A to C in parallel with Eriophorum vaginatum cover and vascular plant leaf area. Our results show that reestablishing a Sphagnum cover is not sufficient to restore a CO₂‐sequestrating function but that after circa 50 years the ecosystem may naturally regain this function over the growing season.     

Peatland restoration: A brief assessment with special reference to Sphagnum bogs

Recent literature on peatland restorationindicates as a general goal repairing orrebuilding ecosystems by restoringecosystem structure, trophic organization,biodiversity, and functions to thosecharacteristic of the type of peatland towhich the damaged ecosystem belonged, or atleast to an earlier successional stage.Attainment requires provision of anappropriate hydrological regime,manipulating surface topography, improvingmicroclimate, adding appropriate diaspores,manipulating base status where necessary,fertilizing in some cases, excludinginappropriate invaders, adaptively managingthrough at least one flood/drought cycle toensure sustainability, and monitoring on ascale of decades. Several matchingconditions favoring or opposing restorationare suggested.In the restoration of peatlands, successeshave generally been those of short-termrepair. Periods of restoration have beenmuch too short to ensure progression to, oreven well toward, a fully functionalpeatland reasonably compatible with thepristine state of similar peatlandselsewhere, although with altered surfacepatterns.Long-term monitoring ofpeatland-restoration projects is essentialfor a better understanding of how to carryout such restoration successfully.Paleoecology is suggested as anunderutilized tool in peatlandrestoration.     

让自然做功的河道生态修复——以呼和浩特大黑河城区段景观概念规划为例

河道是生态敏感、脆弱而又具有显著景观价值的重要生态廊道。只有在规划设计实践中发现和顺应河流的自然形态和自然演变规律,在尊重和保护的基础上进行生态修复,才能真正走向人地和谐。本文以呼和浩特大黑河城区段为研究对象,分别在时间和空间维度上分析总结了大黑河河道形态演变的主要规律和自然诱因,并在此基础上提出了引导洪水对河道形态进行自我修复的生态修复方法。在整体生态系统修复策略上,提出了建立“四维一体”的生态系统修复模型。从林、堤、滩、水4个方面分别探讨了生态景观设计的过程,突出了河道生态功能和景观特色的结合。     

The effect of establishing native woodland on habitat selection and ranging of moorland mountain hares (Lepus timidus), a flexible forager

Mountain hares Lepus timidus L. typify species that occupy a broad geographic range and have flexible foraging and nutritional strategies. Such species may show a range of responses to habitat modification. This study aimed to provide a basis for prediction of the impact of mountain hares on woodland establishment, and of woodland establishment on mountain hare distribution. The selection of and the extent of incorporation of new woodland into the home range of mountain hares was investigated in an area where Scots pine Pinus sylvestris L. woodland was establishing within their usual habitat in Britain, upland heather moorland. Seasonal home, day and night-range sizes of radio-tracked mountain hares were determined using the multinuclear probability polygon technique and analysed using residual maximum likelihood (REML). Habitat selection was analysed using compositional analysis. Three main habitat types were available to hares: heather moorland with trees, heather moorland and grassland-mire. Mean home-range size of mountain hares in summer was 10.3 ha and in winter 9.6 ha. There were no significant seasonal or sex differences in home-range size. Females selected grassland-mire habitat in summer and showed no strong selection for any habitat in winter. Males selected heather moorland in both summer and winter. Heather moorland with trees was not selected preferentially by mountain hares of either sex in summer or winter. The absence of selection for areas of newly establishing-Scots pine woodland suggests that any browsing damage to trees by hares is most likely to be a function of the local abundance of mountain hares, rather than a result of active preference of hares for the modified habitat.     

Effects of Rewetting Measures in Dutch Raised Bog Remnants on Assemblages of Aquatic Rotifera and Microcrustaceans

Species differ in their life cycle, habitat demands and dispersal capacity. Consequently different species or species groups may respond differently to restoration measures. To evaluate effects of restoration measures in raised bog remnants on aquatic microinvertebrates, species assemblages of Rotifera and microcrustaceans were sampled in 10 rewetted and 10 non-rewetted sites, situated in 7 Dutch raised bog remnants. A total of 129 species (Rotifera 108, Cladocera 15, Copepoda 6 species) were found. The species assemblages, total numbers of species and numbers of characteristic raised bog species did not differ between the 10 rewetted and 10 non-rewetted sites. The dominant pattern in the variation in microinvertebrate assemblages could be explained by the presence or absence of open water and variation in physico-chemical variables of surface water and organic matter. Furthermore, the species assemblages of water bodies situated in the same area were on average more similar to each other than to assemblages from other areas. These differences between areas may be due to differences in environmental conditions of water bodies, and possibly also to differences in the local species pool and the subsequent immigration sequence of species. We conclude that, in contrast to earlier findings on aquatic macroinvertebrates, populations of microinvertebrate species, including characteristic species, can either persist in the raised bog remnants during the process of rewetting or (re-)establish within a relatively short period of time (less than about 5 years).