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Deciduous Woodland (deciduous + woodland)

Distribution by Scientific Domains

Life Sciences	50%
Earth and Environmental Science	33%
Humanities and Social Sciences	16%

Selected Abstracts

The contribution of geoarchaeology to understanding the environmental history and archaeological resources of the Trent Valley, U.K.

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 2 2005
Andy J. Howard
This paper provides a review of the contribution that geoarchaeological research has played in elucidating the landscape history of the Trent Valley, U.K. Ameliorating climate in the immediate postglacial led to the expansion of mixed deciduous woodland across the valley floor and the development of an anastomosing channel. In the Lower Trent, fluvial and vegetation development may have been influenced by sea-level change. Around 4000 B.C., the character of the valley floor changed, demonstrated by the dating of tree trunks interbedded within gravel deposits. Synchronicity of changing geomorphological and hydrological processes is suggested, and, while the causal mechanism of this change are not fully understood, tree trunks which were clearly felled have been identified in the valley and provide significant evidence. The later prehistoric and historic archaeological remains, including fishweirs, bridges, and mill dams, point to increasing human activity, and environmental evidence documents the increasing effects of agriculture on the catchment. © 2005 Wiley Periodicals, Inc. [source]

New perspectives on Holocene landscape development in the southern English chalklands: The upper Allen valley, Cranborne Chase, Dorset

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 2 2005
C. French
A combination of on- and off-site paleoenvironmental and archaeological investigations of the upper Allen valley of Dorset, conducted from 1998,2002, has begun to indicate a different model of prehistoric landscape development to those previously put forward for this part of the southern English chalk downlands. Woodland growth in the earlier Holocene appears to have been slower and patchier than the presumed model of full climax deciduous woodland rapidly attained in a warming environment. With open areas still strongly present in the Mesolithic, the area witnessed its first exploitation, thus slowing and altering soil development. Consequently, many areas perhaps never developed thick, well-structured, brown forest earths, but more probably thin brown earths. By the later Neolithic period, these soils had become thin rendzinas, largely as a consequence of human exploitation and the predominance of pastoral land use. The early presence of thinner and less well-developed soils over large areas of downland removes the necessity for envisaging extensive soil erosion and the accumulation of thick colluvial and alluvial deposits in the dry valleys and valley floor as often postulated. If there were major changes in the vegetation and soil complexes in this area of chalk downland, these had already occurred by the Neolithic rather than the Bronze Age as often suggested, and the area has remained relatively stable ever since. This has major implications for models of prehistoric land use in the southern chalkland region, such as a much greater degree of stability in prehistoric and historic times, variability within sub-regions, and differences between different parts of the chalk downlands than had previously been envisaged. © 2005 Wiley Periodicals, Inc. [source]

UV-B effect on Quercus robur leaf litter decomposition persists over four years

GLOBAL CHANGE BIOLOGY, Issue 4 2001
K. K. Newsham
Summary The effects of elevated UV-B (280,315 nm) radiation on the long-term decomposition of Quercus robur leaf litter were assessed at an outdoor facility in the UK by exposing saplings to elevated UV-B radiation (corresponding to a 30% increase above the ambient level of erythemally weighted UV-B, equivalent to that resulting from a c. 18% reduction in ozone column) under arrays of cellulose diacetate-filtered fluorescent UV-B lamps that also produced UV-A radiation (315,400 nm). Saplings were also exposed to elevated UV-A radiation alone under arrays of polyester-filtered fluorescent lamps and to ambient solar radiation under arrays of nonenergized lamps. After 8 months of irradiation, abscised leaves were placed into litter bags and allowed to decompose in the litter layer of a mixed deciduous woodland for 4.08 years. The dry weight loss of leaf litter from saplings irradiated with elevated UV-B and UV-A radiation during growth was 17% greater than that of leaf litter irradiated with elevated UV-A radiation alone. Annual fractional weight loss of litter (k), and the estimated time taken for 95% of material to decay (3/k) were respectively increased and decreased by 27% for leaf litter exposed during growth to elevated UV-B and UV-A radiation, relative to that exposed to UV-A alone. The present data corroborate those from a previous study indicating that UV-B radiation applied during growth accelerates the subsequent decomposition of Q. robur leaf litter in soil, but indicate that this effect persists for over four years after abscission. [source]

Tawny Owls Strix aluco with reliable food supply produce male-biased broods

IBIS, Issue 1 2007
KASI B. DESFOR
Tawny Owls Strix aluco have been reported to skew the sex ratio of their offspring towards males when facing food shortage during the nestling period (and vice versa), because female fitness is more compromised by food shortage during development than male fitness. To test the generality of these results we used a DNA marker technique to determine the sex ratio in broods of Tawny Owls in Danish deciduous woodland during two years of ample food supply (rodent population outbreak) and two years of poor food supply. Of 268 nestlings, 59% were males (95% CI: 53,65%). This proportion was higher than previously reported for the species (49% in Northumberland, UK, and 52% in Hungary), but consistent with Fisherian sex allocation, which predicts a male bias of c. 57% based on inferred differences in energy requirements of male and female chicks. Contrary to previous results, brood sex ratios were not correlated with the resource abundance during the breeding seasons, despite considerable variation in breeding frequency, brood size or hatching date across years. Brood sex ratios were unaffected by brood reduction prior to DNA sampling, and nestling mortality rates after DNA sampling were not related to gender. The inconsistency between the sex ratio allocation patterns in our study and previous investigations suggests that adaptive sex allocation strategies differ across populations. These differences may relate to reproductive constraints in our population, where reproductive decisions seem primarily to concern whether to lay eggs at all, rather than adjust the sex ratio to differences in starvation risk of nestlings. [source]

Prediction of butterfly diversity hotspots in Belgium: a comparison of statistically focused and land use-focused models

JOURNAL OF BIOGEOGRAPHY, Issue 12 2003
Dirk Maes
Abstract Aim, We evaluate differences between and the applicability of three linear predictive models to determine butterfly hotspots in Belgium for nature conservation purposes. Location, The study is carried out in Belgium for records located to Universal Transverse Mercator (UTM) grid cells of 5 × 5 km. Methods, We first determine the relationship between factors correlated to butterfly diversity by means of modified t -tests and principal components analysis; subsequently, we predict hotspots using linear models based on land use, climate and topographical variables of well-surveyed UTM grid cells (n = 197). The well-surveyed squares are divided into a training set and an evaluation set to test the model predictions. We apply three different models: (1) a ,statistically focused' model where variables are entered in descending order of statistical significance, (2) a ,land use-focused' model where land use variables known to be related to butterfly diversity are forced into the model and (3) a ,hybrid' model where the variables of the ,land use-focused model' are entered first and subsequently complemented by the remaining variables entered in descending order of statistical significance. Results, A principal components analyses reveals that climate, and to a large extent, land use are locked into topography, and that topography and climate are the variables most strongly correlated with butterfly diversity in Belgium. In the statistically focused model, biogeographical region alone explains 65% of the variability; other variables entering the statistically focused model are the area of coniferous and deciduous woodland, elevation and the number of frost days; the statistically focused model explains 77% of the variability in the training set and 66% in the evaluation set. In the land use-focused model, biogeographical region, deciduous and mixed woodland, natural grassland, heathland and bog, woodland edge, urban and agricultural area and biotope diversity are forced into the model; the land use-focused model explains 68% of the variability in the training set and 57% in the evaluation set. In the hybrid model, all variables from the land use-focused model are entered first and the covariates elevation, number of frost days and natural grassland area are added on statistical grounds; the hybrid model explains 78% of the variability in the training set and 67% in the evaluation set. Applying the different models to determine butterfly diversity hotspots resulted in the delimitation of spatially different areas. Main conclusions, The best predictions of butterfly diversity in Belgium are obtained by the hybrid model in which land use variables relevant to butterfly richness are entered first after which climatic and topographic variables were added on strictly statistical grounds. The land use-focused model does not predict butterfly diversity in a satisfactory manner. When using predictive models to determine butterfly diversity, conservation biologists need to be aware of the consequences of applying such models. Although, in conservation biology, land use-focused models are preferable to statistically focused models, one should always check whether the applied model makes sense on the ground. Predictive models can target mapping efforts towards potentially species-rich sites and permits the incorporation of un-surveyed sites into nature conservancy policies. Species richness distribution maps produced by predictive modelling should therefore be used as pro-active conservation tools. [source]

Biostratigraphic and aminostratigraphic constraints on the age of the Middle Pleistocene glacial succession in north Norfolk, UK,

JOURNAL OF QUATERNARY SCIENCE, Issue 6 2009
Richard C. Preece
Abstract Considerable debate surrounds the age of the Middle Pleistocene glacial succession in East Anglia following some recent stratigraphical reinterpretations. Resolution of the stratigraphy here is important since it not only concerns the glacial history of the region but also has a bearing on our understanding of the earliest human occupation of north-western Europe. The orthodox consensus that all the tills were emplaced during the Anglian (Marine Isotope Stage (MIS) 12) has recently been challenged by a view assigning each major till to a different glacial stage, before, during and after MIS 12. Between Trimingham and Sidestrand on the north Norfolk coast, datable organic sediments occur immediately below and above the glacial succession. The oldest glacial deposit (Happisburgh Till) directly overlies the ,Sidestrand Unio -bed', here defined as the Sidestrand Hall Member of the Cromer Forest-bed Formation. Dating of these sediments therefore has a bearing on the maximum age of the glacial sequence. This paper reviews the palaeobotany and describes the faunal assemblages recovered from the Sidestrand Unio -bed, which accumulated in a fluvial environment in a fully temperate climate with regional deciduous woodland. There are indications from the ostracods for weakly brackish conditions. Significant differences are apparent between the Sidestrand assemblages and those from West Runton, the type site of the Cromerian Stage. These differences do not result from contrasting facies or taphonomy but reflect warmer palaeotemperatures at Sidestrand and a much younger age. This conclusion is suggested by the higher proportion of thermophiles at Sidestrand and the occurrence of a water vole with unrooted molars (Arvicola) rather than its ancestor Mimomyssavini with rooted molars. Amino acid racemisation data also indicate that Sidestrand is significantly younger than West Runton. These data further highlight the stratigraphical complexity of the ,Cromerian Complex' and support the conventional view that the Happisburgh Till was emplaced during the Anglian rather than the recently advanced view that it dates from MIS 16. Moreover, new evidence from the Trimingham lake bed (Sidestrand Cliff Formation) above the youngest glacial outwash sediments (Briton's Lane Formation) indicates that they also accumulated during a Middle Pleistocene interglacial , probably MIS 11. All of this evidence is consistent with a short chronology placing the glacial deposits within MIS 12, rather than invoking multiple episodes of glaciation envisaged in the ,new glacial stratigraphy' during MIS 16, 12, 10 and 6. Copyright © 2009 John Wiley & Sons, Ltd. [source]

The Yellow-necked Mouse Apodemus flavicollis in Britain: status and analysis of factors affecting distribution

MAMMAL REVIEW, Issue 3-4 2001
Aidan C. W. Marsh
ABSTRACT A national survey of the Yellow-necked Mouse (Apodemus flavicollis) in Britain was undertaken by The Mammal Society. The live-trapping study sampled small mammal populations from 168 deciduous woodlands in autumn 1998. Within their range, Yellow-necked Mice were widespread in deciduous woodland and were more abundant than Wood Mice in 15% of the woodlands sampled. These trapping records, as well as records solicited from local recorders, record centres and individuals, supplemented the existing distribution map, confirming the general pattern, but with minor extensions to some range borders. Yellow-necked Mice were found in woodland of all ages, but were more common in woods of ancient origin than in younger woodland. Woodland size was not important in determining the presence or abundance of Yellow-necked Mice, but they were more often absent from woods more than 2 km from neighbouring substantial woodland. The presence of Yellow-necked Mice did not affect the relative abundance of Wood Mice (Apodemus sylvaticus). However, the decline in the proportion of breeding male Wood Mice at the end of the main breeding season was more marked in those woods that also contained Yellow-necked Mice. Where their ranges overlapped, Bank Voles (Clethrionomys glareolus) were less abundant where Yellow-necked Mice were also present. The distribution of the Yellow-necked Mouse was explored with respect to a number of climatic, soil and habitat variables. Maximum summer temperature was the most significant variable explaining distribution, although woodland cover variables also contributed. Soil moisture and pH, mean rainfall and winter temperature parameters did not predict Yellow-necked Mouse distribution. Low summer temperature may limit Yellow-necked Mouse distribution through its impact on tree seed production and diversity. Climatic change leading to a rise in summer temperature might encourage range expansion by Yellow-necked Mice, if their other habitat requirements are met. [source]

Carnivore biodiversity in Tanzania: revealing the distribution patterns of secretive mammals using camera traps

ANIMAL CONSERVATION, Issue 2 2010
N. Pettorelli
Abstract Biodiversity monitoring is critical to assess the effectiveness of management activities and policy change, particularly in the light of accelerating impacts of environmental change, and for compiling national responses to international obligations and agreements. Monitoring methods able to identify species most likely to be affected by environmental change, and pinpoint those changes with the strongest impacts, will enable managers to target efforts towards vulnerable species and significant threats. Here we take a new approach to carnivore monitoring, combining camera-trap surveys with ecological niche factor analysis to assess distribution and patterns of habitat use of mammalian carnivore assemblages across northern Tanzania. We conducted 11 surveys over 430 camera-trap stations and 11 355 trap-days. We recorded 23 out of 35 carnivore species known to occur in Tanzania and report major extensions to the known distribution of the bushy-tailed mongoose Bdeogale crassicauda, previously thought to be rare. Carnivore biodiversity tended to be higher in national parks than in game reserves and forest reserves. We explored habitat use for seven species for which we had sufficient information. All species tended to be found near rivers and southern Acacia commiphora woodlands (except one mongoose species), and avoided deciduous shrubland, favouring deciduous woodland and/or open grassland. All species tended to avoid croplands suggesting that habitat conversion to agriculture could have serious implications for carnivore distribution. Our study provides a first example where camera-trap data are combined with niche analyses to reveal patterns in habitat use and spatial distribution of otherwise elusive and poorly known species and to inform reserve design and land-use planning. Our methodology represents a potentially powerful tool that can inform national and site-based wildlife managers and policy makers as well as international agreements on conservation. [source]

Mapping tree species in temperate deciduous woodland using time-series multi-spectral data

APPLIED VEGETATION SCIENCE, Issue 1 2010
R. A. Hill
Abstract Questions: What is the optimum combination of image dates across a growing season for tree species differentiation in multi-spectral data and how does species composition affect overstorey canopy density? Location: Monks Wood, Cambridgeshire, eastern England, UK. Methods: Six overstorey tree species were mapped using five Airborne Thematic Mapper images acquired across the 2003 growing season (17 March, 30 May, 16 July, 23 September, 27 October). After image pre-processing, supervised maximum likelihood classification was performed on the images and on all two-, three-, four- and five-date combinations. Relationships between tree species composition and canopy density were assessed using regression analyses. Results: The image with the greatest tree species discrimination was acquired on 27/10 when the overstorey species were in different stages of leaf tinting and fall. In this image, tree species were mapped with an overall classification accuracy (OCA) of 71% (kappa 0.63). A similar OCA was achieved from the other four images combined (OCA 72%, kappa 0.64). The highest classification accuracy was achieved by combining three images: 17 March, 16 July, 27 October. This achieved an OCA of 84% (kappa 0.79), increasing to 88% (kappa 0.85) after a post-classification clump and sieve procedure. Canopy height and percentage cover of oak explained 72% of variance in canopy density. Conclusions: The ability to discriminate and map temperate deciduous tree species in airborne multi-spectral imagery is increased using time-series data. An autumn image supplemented with an image from both the green-up and full-leaf phases was optimum. The derived tree species map provides a more powerful ecological tool for determining woodland structural/compositional relationships than field-based measures. [source]

A beetle's eye view of London from the Mesolithic to Late Bronze Age

GEOLOGICAL JOURNAL, Issue 5 2009
Scott A. Elias
The aim of this paper is to reconstruct the environmental history of the London region, based on changes in beetle faunal assemblages from the Mesolithic to Late Bronze Age. Eight sites were studied, all but one of which are within 2,km of the modern course of the Thames. The sites produced 128 faunal assemblages that yielded 218 identified species in 41 families of Coleoptera (beetles). Beetle faunas of Mesolithic age indicate extensive wetlands near the Thames, bordered by rich deciduous woodlands. The proportion of woodland species declined in the Neolithic, apparently because of the expansion of wetlands, rather than because of human activities. The Early Bronze Age faunas contained a greater proportion of coniferous woodland and aquatic (standing water) species. An increase in the dung beetle fauna indicates the presence of sheep, cattle and horses, and various beetles associated with crop lands demonstrate the local rise of agriculture, albeit several centuries after the beginnings of farming in other regions of Britain. Late Bronze Age faunas show the continued development of agriculture and animal husbandry along the lower Thames. About 33% of the total identified beetle fauna from the London area sites have limited modern distributions or are extinct in the U.K. Some of these species are associated with the dead wood found in primeval forests; others are wetland species whose habitat has been severely reduced in recent centuries. The third group is stream-dwelling beetles that require clean, clear waters and river bottoms. Copyright © 2009 John Wiley & Sons, Ltd. [source]

The Yellow-necked Mouse Apodemus flavicollis in Britain: status and analysis of factors affecting distribution

Seven-Year Survival of Perennial Herbaceous Transplants in Temperate Woodland Restoration

RESTORATION ECOLOGY, Issue 3 2006
Larissa M. Mottl
Abstract Little is known about restoring the perennial herbaceous understory of Midwestern deciduous woodlands, despite the significant and widespread degradation of remnants due to human activities. Because many woodland understory species have reproductive characters that make reestablishment from seed slow or difficult, we investigated transplanting as a strategy for introducing 24 species to a degraded early-successional woodland in central Iowa, U.S.A. Plants were planted in single-species groups of generally four individuals, and then monitored for survival five times over a 7-year period, and for flowering during the first year. After 7 years, persistence of these groups was 57% averaged across species. Survival in years 5,7 does not reflect individuals that spread beyond the original planting units by self-sowing or vegetative spread and is therefore a minimum estimate of the abundance of many species at the site. Mean percent flowering was 72% across single-species groups for 15 species monitored. We consider these survival and flowering rates acceptable indicators of establishment success, especially given drought conditions at our site in the first few years and lack of weed control beyond the first year, and evidence that transplanted species were establishing outside the original planting locations. Additional work is needed to investigate regional differences in transplant success, and methods for sustainable production of species are not suitable for introduction by seed. We caution that our results do not necessarily apply to the restoration of rare species. [source]