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Land-use Activities (land-use + activity)
Selected AbstractsTOPCAT-NP: a minimum information requirement model for simulation of flow and nutrient transport from agricultural systemsHYDROLOGICAL PROCESSES, Issue 14 2008P. F. Quinn Abstract Future catchment planning requires a good understanding of the impacts of land use and management, especially with regard to nutrient pollution. A range of readily usable tools, including models, can play a critical role in underpinning robust decision-making. Modelling tools must articulate our process understanding, make links to a range of catchment characteristics and scales and have the capability to reflect future land-use management changes. Hence, the model application can play an important part in giving confidence to policy makers that positive outcomes will arise from any proposed land-use changes. Here, a minimum information requirement (MIR) modelling approach is presented that creates simple, parsimonious models based on more complex physically based models, which makes the model more appropriate to catchment-scale applications. This paper shows three separate MIR models that represent flow, nitrate losses and phosphorus losses. These models are integrated into a single catchment model (TOPCAT-NP), which has the advantage that certain model components (such as soil type and flow paths) are shared by all three MIR models. The integrated model can simulate a number of land-use activities that relate to typical land-use management practices. The modelling process also gives insight into the seasonal and event nature of nutrient losses exhibited at a range of catchment scales. Three case studies are presented to reflect the range of applicability of the model. The three studies show how different runoff and nutrient loss regimes in different soil/geological and global locations can be simulated using the same model. The first case study models intense agricultural land uses in Denmark (Gjern, 114 km2), the second is an intense agricultural area dominated by high superphosphate applications in Australia (Ellen Brook, 66 km2) and the third is a small research-scale catchment in the UK (Bollington Hall, 2 km2). Copyright © 2007 John Wiley & Sons, Ltd. [source] Anthropogenic disturbance and the formation of oak savanna in central Kentucky, USAJOURNAL OF BIOGEOGRAPHY, Issue 5 2008Ryan W. McEwan Abstract Aim, To deepen understanding of the factors that influenced the formation of oak savanna in central Kentucky, USA. Particular attention was focused on the link between historical disturbance and the formation of savanna ecosystem structure. Location, Central Kentucky, USA. Methods, We used dendrochronological analysis of tree-ring samples to understand the historical growth environment of remnant savanna stems. We used release detection and branch-establishment dates to evaluate changes in tree growth and the establishment of savanna physiognomy. We contrasted our growth chronology with reference chronologies for regional tree growth, climate and human population dynamics. Results, Trees growing in Kentucky Inner Bluegrass Region (IBR) savanna remnants exhibited a period of suppression, extending from the establishment date of the tree to release events that occurred c. 1800. This release resulted in a tripling of the annual radial growth rate from levels typical of oaks suppressed under a forest canopy (< 1 mm year,1) to levels typical of open-grown stems (3 mm year,1). The growth releases in savanna trees coincided with low branch establishment. Over the release period, climatic conditions remained relatively constant and growth in regional forest trees was even; however, the growth increase in savanna stems was strongly correlated with a marked increase in Euro-American population density in the region. Main conclusions, Our data suggest that trees growing in savanna remnants originated in the understorey of a closed canopy forest. We hypothesize that Euro-American land clearing to create pasturelands released these trees from light competition and resulted in the savanna physiognomy that is apparent in remnant stands in the IBR. Although our data suggest that savanna trees originated in a forest understorey, this system structure itself may have been a result of an unprecedented lack of Native American activity in the region due to population loss associated with pandemics brought to North America by Euro-Americans. We present a hypothetical model that links human population dynamics, land-use activities and ecosystem structure. Our model focuses on the following three land-use eras: Native American habitation/utilization; land abandonment; and Euro-American land clearance. Ecological understanding of historical dynamics in other ecosystems of eastern North America may be enhanced through recognition of these eras. [source] Geoarchaeology of the Milfield Basin, northern England; towards an integrated archaeological prospection, research and management frameworkARCHAEOLOGICAL PROSPECTION, Issue 2 2002David G. Passmore Abstract This paper presents the results of geoarchaeological investigations undertaken on the valley floor of the Milfield Basin in Northumberland, northern England. The area has a regionally and nationally important archaeological record, including a series of major neolithic and Anglian settlements, but has hitherto lacked archaeological assessment and management guidelines appropriate to the wide range of late-glacial and post-glacial environmental settings in the basin. This project has used geomorphological techniques to delimit and classify a total of nine valley floor landform elements in terms of their geomorphology and their known and potential archaeological and palaeoenvironmental associations. Terraced glaciodeltaic and glaciofluvial sand and gravel landforms comprise the oldest landform elements described here and have formed the primary regional focus for prehistoric and early historic settlement and associated subsistence and ritual activity. These landforms have experienced little post-glacial geomorphological activity, but their multiperiod archaeological landscapes lie beneath a shallow soil cover and are vulnerable to land-use activities that disturb terrace soils and underlying sediments. A second group of landform elements are of Holocene age and include localized surface peats, alluvial fans, colluvial deposits and extensive deposits of terraced alluvium. Archaeological landscapes in these environments may lie buried intact and unrecorded beneath protective covers of sediment although locally they may have been subject to erosion and reworking by fluvial and slope processes. Holocene alluviation may account, at least in part, for the paucity of recorded archaeology in these parts of the basin. However, peat and organic-rich sedimentary sequences identified here (including four 14C dated peat sequences) offer an opportunity to elucidate the environmental context and land-use histories of local prehistoric and early historic communities in the basin, and hence also should be regarded as an archaeological resource. Discussion of landform elements and their archaeological associations is followed by a brief outline of evaluation criteria developed with the aim of ensuring effective long-term management of archaeological and palaeoenvironmental resources. It is concluded that geoarchaeological analysis of landform elements may be considered central to development of frameworks intended to underpin future programmes of archaeological research and the development of cultural resource management and evaluation strategies. Copyright © 2002 John Wiley & Sons, Ltd. [source] Geostatistical and multi-elemental analysis of soils to interpret land-use history in the Hebrides, ScotlandGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 4 2007J.A. Entwistle In the absence of documentary evidence about settlement form and agricultural practice in northwest Scotland before the mid-18th century, a geoarchaeological approach to reconstructing medieval land use and settlement form is presented here. This study applies multielemental analysis to soils previously collected from a settlement site in the Hebrides and highlights the importance of a detailed knowledge of the local soil environment and the cultural context. Geostatistical methods were used to analyze the spatial variability and distribution of a range of soil properties typically associated with geoarchaeological investigations. Semivariograms were produced to determine the spatial dependence of soil properties, and ordinary kriging was undertaken to produce prediction maps of the spatial distribution of these soil properties and enable interpolation over nonsampled locations in an attempt to more fully elucidate former land-use activity and settlement patterns. The importance of identifying the spatial covariance of elements and the need for several lines of physical and chemical evidence is highlighted. For many townships in the Hebrides, whose precise location and layout prior to extensive land reorganization in the late 18th,early 19th century is not recoverable through plans, multi-elemental analysis of soils can offer a valuable prospective and diagnostic tool. © 2007 Wiley Periodicals, Inc. [source] | ||||||||||