163,221 research outputs found
Breeding bird populations of Irish peatlands : capsule peatlands are very important habitats for birds despite low species diversity
No full textAims to describe the variation in breeding bird populations that occur on different types of Irish peatlands and their associated habitat characteristics.
Methods: Bird abundance and diversity were compared between four peatland habitat types: fens; raised bogs; Atlantic blanket bogs; and montane blanket bogs at twelve study sites using transects. Various measures of habitat quality were also taken at each location.
Results: Only 21 species were recorded during the study with Meadow Pipit Anthus pratensis and Sky Lark Alauda arvensis accounting for over 80% of all birds recorded. Fens had greater bird species diversity and densities than the other three peatland types. Raised bogs, Atlantic blanket bogs and montane blanket bogs were very similar in terms of their avian diversity. Each of the recorded bird species were associated with different aspects of the peatland habitat.
Conclusion: This study shows that despite the relatively low avian species diversity of Irish peatlands, they are of enormous conservation value due to the presence of species of high conservation concern such as Red Grouse (Willow Ptarmigan) Lagopus lagopus and Eurasian Curlew Numenius arquata.Other funderEnvironmental Protection Agency (EPA)ke, ab, sp, li - TS 26.04.1
Vegetation and peat characteristics of restiad bogs on Chatham Island (Rekohu), New Zealand
No full textRestiad bogs dominated by Sporadanthus traversii on Chatham Island, New Zealand, were sampled to correlate vegetation patterns and peat properties, and to compare with restiad systems dominated by Sporadanthus ferrugineus and Empodisma minus in the Waikato region, North Island, New Zealand. Classification and ordination resulted in five groups that reflected a disturbance gradient. The largest S. traversii group, which comprised plots from central, relatively intact bogs, had the lowest levels of total nitrogen (mean 1.20 mg cm-3), total phosphorus (mean 0.057 mg cm-3), total potassium (mean 0.083 mg cm-3), and available phosphorus (mean 18.6 μg cm-3). Modification by drainage, stock, and fires resulted in a decline of S. traversii and an increase of Gleichenia dicarpa fern cover, together with elevated peat nutrient levels and higher bulk density. Compared with peat dominated by Sporadanthus ferrugineus or Empodisma minus in relatively unmodified Waikato restiad bogs, Chatham Island peat under S. traversii has significantly higher total potassium, total nitrogen, available phosphorus, bulk density, and von Post decomposition indices, and significantly lower pH. Sporadanthus traversii and Empodisma minus have similar ecological roles in restiad bog development, occupying a relatively wide nutrient range, and regenerating readily from seed after fire. Despite differences in root morphology, S. traversii and E. minus are the major peat formers in raised restiad bogs on Chatham Island and in Waikato, respectively, and could be regarded as ecological equivalents
Restoration of lowland raised bogs damaged by peat extraction - with particular emphasis on Sphagnum regeneration.
No full text1. Revegetation trends in abandoned peat workings indicate that peat cuttings are
generally too dry for spontaneous re-establishment of raised bog vegetation. The latter
was restricted to small flooded peat pits which had recolonised 'hydroserally' to
support floating rafts of bog vegetation.
2. The water storage capacity of cut-over bog surfaces is low compared with
undisturbed bog and blocking drains in a peat field at Thorne Moors, S. Yorks, was
insufficient to prevent water-table instability. Experiments suggest this may severely
inhibit Sphagnum growth. Lagoons may increase water storage on a bog surface and
facilitate development of raised bog vegetation as floating rafts. This 'hydroseral'
approach may be necessary to restore raised bog vegetation to some areas.
3. Hydrochemical conditions of cut-over sites may differ significantly from
undisturbed bogs with implications for Sphagnum growth. Water samples from a peat
field at Thorne Moors were comparatively acidic and contained comparatively high
concentrations of most major ions (particularly NH4 and SO4), except phosphorus.
Moderate nutrient enrichment is unlikely to adversely affect Sphagnum and additions
of phosphorus to flooded peat pits significantly increased its growth. In solution
culture, low pH (3.0-3.5) was sub-optimal for Sphagnum growth, but the use of
CaCO3 to reduce acidity in the field had a toxic effect.
4. Sphagnum recolonisation may be limited by availability of propagules in cut-over
areas. Experiments indicate that deliberate re-introduction encourages Sphagnum raft
development, which is pioneered by aquatic species that regenerate more prolifically
from fragments than intact gametophytes. Sphagnum rafts are encouraged in shallow
water (< 5 0cm) and pools of small area. Numerous management options exist
physically and chemically assisting raft development
Upland wetlands in the Namoi catchment : mapping distribution and disturbance classes of fens, bogs and lagoons
No full textTo assist with planning and conservation strategies, mapping of wetlands above 700 m elevation across the Namoi Catchment (east of Tamworth) was undertaken. The number of hectares of each type within this high-elevation region, the area currently in conservation reserves and the status of these remnants was assessed. 1 001 wetlands were mapped and allocated to three wetland types (fens, bogs and lagoons) and six disturbance groups (based on agricultural clearing and presence of dams). Total wetlands cover was 4 490 ha, of which fens were the most common, followed by bogs and a single lagoon. The smallest wetland was 0.12 ha in size, the largest 113 ha and the average 5 ha. Only 10% of all wetlands were considered to be in near natural state with only 5.5% of all wetland area protected within conservation reserves
Vegetation of montane bogs in east-flowing catchments of northern New England, New South Wales
No full textThe floristics of the montane bogs in east-flowing catchments of northern New England, north-eastern New South Wales (lat 28° 47’–31° 25’ S; long 151° 50’–152° 30’ E), are described from 62 full floristic survey sites (20 x 20 m in area). Eight vegetation communities are based on flexible UPGMA analysis of cover-abundance scores of vascular plant taxa. Shrub species make up 26% of the flora and herb species 69%, with the remaining taxa trees, climbers or vines. Shrub species were of little diagnostic value, as a few common dominants were shared across most communities. The herbaceous layer was found to be of better circumscriptive value. Communities described (based on dominant herbaceous species) are: (1) Themeda australis – Gonocarpus micranthus, (2) Baumea articulata – Baloskion stenocoleum, (3) Lepidosperma limicola – Baloskion stenocoleum, (4) Baloskion fimbriatum – Lomandra longifolia, (5) Lepyrodia scariosa – Blandfordia grandiflora, (6) Lepidosperma gunnii – Lepidosperma scariosa, (7) Baloskion stenocoleum – Empodisma minus, (8) Lepidosperma limicola – Xyris operculata. The mean annual moisture index was found to account for 26% of the variation in species density. These montane bog systems are some of the richest in Australia, with a high number of rare and restricted taxa. They are vulnerable to both present landuse practices and future changes in climate, are restricted in area, and need further conservation efforts to ensure their long-term survival
Field Simulation of Global Change: Transplanting Northern Bog Mesocosms Southward
No full textA large proportion of northern peatlands consists of Sphagnum-dominated ombrotrophic bogs. In these bogs, peat mosses (Sphagnum) and vascular plants occur in an apparent stable equilibrium, thereby sustaining the carbon sink function of the bog ecosystem. How global warming and increased nitrogen (N) deposition will affect the species composition in bog vegetation is still unclear. We performed a transplantation experiment in which mesocosms with intact vegetation were transplanted southward from north Sweden to north-east Germany along a transect of four bog sites, in which both temperature and N deposition increased. In addition, we monitored undisturbed vegetation in control plots at the four sites of the latitudinal gradient. Four growing seasons after transplantation, ericaceous dwarf shrubs had become much more abundant when transplanted to the warmest site which also had highest N deposition. As a result ericoid aboveground biomass in the transplanted mesocosms increased most at the southernmost site, this site also had highest ericoid biomass in the undisturbed vegetation. The two dominant Sphagnum species showed opposing responses when transplanted southward; Sphagnum balticum height increment decreased, whereas S. fuscum height increment increased when transplanted southward. Sphagnum production did not differ significantly among the transplanted mesocosms, but was lowest in the southernmost control plots. The dwarf shrub expansion and increased N concentrations in plant tissues we observed, point in the direction of a positive feedback toward vascular plant-dominance suppressing peat-forming Sphagnum in the long term. However, our data also indicate that precipitation and phosphorus availability influence the competitive balance between Sphagnum, dwarf shrubs and graminoids
Lowland Bogs, Fens and Reedswamps
No full textThis chapter reviews the current and historical studies of the bird communities of lowland bogs, fens and reedswamps in Ireland. The habitat types and bird communities described include raised bogs, cutover and cutaway peatlands and reedswamps.Environmental Protection Agenc
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
Patterns of mid-Holocene climate change: evidence from the peat archive
No full textWith growing concerns over future climate change, the need to understand past climate variability has become an important topic of research. In this thesis, a gap in knowledge of the transition to modern climatic conditions during the mid-Holocene is identified and addressed. Mid-Holocene atmospheric moisture availability has been reconstructed from five raised mires (Kortlandamossen, Tore Hill Moss, Raeburn Flow, Gällseredsmossen, and Misten Bog) located on geographical and climatological gradients across northwest Europe.In this thesis, a new testate amoebae-based palaeohydrological transfer function for south-central Sweden and an improved indicator-weighted Hydroclimatic Index (HCI) were created in order to establish univariate measures of mid-Holocene bog surface wetness (BSW). Together with detrended correspondence analysis, the HCI and testate amoebae transfer function were applied to palaeoecological data from the five bogs, in order to reconstruct climatic variability across northwest Europe from c. 9000 before present (BP) until c. 3500 BP. A series of wet and dry excursions of the bog surfaces were identified on all five bogs. These BSW changes were compared with palaeoclimatic evidence from the wider literature on a local, regional, continental and hemispheric scale. Throughout the early- to mid-Holocene, increased BSW on Misten Bog closely coincided with episodes of reduced SST in the North Atlantic. A similar link was established between SST and BSW on Raeburn Flow and Gällseredsmossen, following the end of the Holocene Thermal Maximum (HTM). The results from the analysis demonstrate that the HTM occurred asynchronously across northwest Europe. Reconstructions from all five bogs, except Misten Bog, showed a prolonged dry phase on the bog surface starting prior to c. 7000 BP. The end of the HTM occurred between c. 5600 BP and c. 4800 BP on all sites except Kortlandamossen, where regional environmental mechanisms delayed the end of the HTM. A climatic boundary at the end of the HTM was detected around 57ºN, with sites south of 57ºN experiencing the termination between c. 5600 BP and c. 5300, while it occurred between c. 4800 BP and c. 4400 BP on the sites north of this latitude. The only period when all five sites displayed similar BSW changes was between c. 4400 BP and c. 4000 BP, a period of global climatic change. A major wetting on the bogs during this time coincided with increased BSW and glacial advances across Europe as well as high lake levels in France and Switzerland
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