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Agriculturally induced environmental changes in the Burren Karst, Western Ireland
Abstract
The Burren plateau of County Clare is a classic example of a plateau karst characterised by patchy, thin soils, a lack of defined surface drainage, and in the instance of the Burren, a rich floristic, archaeological and landscape heritage.
Since accession to the European Union and, in particular, as a result of Common Agricultural Policy initiatives, attempts have been made to raise farm incomes and to modernise agriculture in areas such as the Burren.
Due to the encouragement of land reclamation and silage production has largely replaced hay farming for winter fodder. These changes pose a threat to groundwater quality by enhancing the leaching of artificial fertilizers or of organic pollutants.
The Burren is highly vulnerable to water pollution from silage effluent because of its thin or absent soils and its highly karstified aquifers.
A full survey of silage clamps was made in the summers of 1991 and 1992. For each site data were collected to derive the following: mass of silage, effluent produced, hazard rating of site to groundwater, likely discharge of effluent to groundwater and groundwater dilution index. About 60% of clamps were considered to be high risk and 23% medium risk. About 92% of all sites probably allow some effluent to infiltrate groundwater.
... The increase in winter housing of cattle in recent years, and the disposal of the resultant wastes in particular, are probably important contributors to eutrophication (McGarrigle et al., 1993;Carton et al., 1995;Allott et al., 1998). Silage making may also be important for phosphorus losses to surface waters, with most incidents occurring in the summer months (Foy et al., 1994;Drew, 1996). Teagasc recommendations for phosphorus additions in silage production are greater than for pastures. ...
... The EPA's Water Quality Monitoring Programme reported median MRP (unfiltered) concentrations of 17 µg l -1 for 1995-1997 (Lucey et al., 1999). Recent studies have, however, recognised the potential of groundwater phosphorus for eutrophication (Drew, 1996;Kilroy et al., 1999;Kilroy, 2001). Drew (1996) identified nutrients in silage and fertiliser as potential threats to groundwater quality in the Burren area. ...
... Recent studies have, however, recognised the potential of groundwater phosphorus for eutrophication (Drew, 1996;Kilroy et al., 1999;Kilroy, 2001). Drew (1996) identified nutrients in silage and fertiliser as potential threats to groundwater quality in the Burren area. The potential for phosphorus transport to surface waters in karstic areas is much greater than in non-karstic areas because of the rapid channelling of water. ...
... To generalise, however, since the early 1970s there has been a growing polarisation of farming activity between fertile accessible lowlands which have become very intensively managed with high levels of mechanical and chemical inputs, and the extensive heritage-rich 'winterages' where farming activity has steadily declined. The environmental implications of this growing imbalance between farming and the landscape have generally been negative and include biodiversity loss, landscape change, water pollution, and an erosion of cultural heritage ( Drew 1996 ;Dunford 2001 ). ...
The vineyards in the Azores, and recent attempts at their recovery
... Such connectivity enables water contaminated with viable and culturable pathogenic microorganisms to reach water sources used for domestic and irrigation purposes. Consequently, the resulting rapid changes in water quality in karst environments due to aquifer heterogeneity and a variety of pollution sources are a major concern for water resource managers and stakeholders (Auckenthaler et al., 2002;Butscher et al., 2011;Drew, 1996;Reischer et al., 2011;Ryan & Meiman, 1996). Springs offer appropriate natural locations for monitoring pollutant concentration dynamics in karst aquifer systems as they provide an integrated picture of contaminant transport through a karst conduit network, compared to wells and boreholes which are not necessarily directly connected to the most transmissive parts of the aquifer (Geyer et al., 2007). ...
Microbial pollution of aquifers is a persistent water quality problem globally which poses significant risks to public health. Karst aquifer systems are exceptionally vulnerable to pollution from faecal contamination sources as a result of rapid recharge of water from the surface via discrete pathways linked to highly conductive, solutionally enlarged conduits alongside strong aquifer heterogeneity. Consequently, rapid changes in microbial water quality, which are difficult to monitor with expensive and time-consuming conventional microbiological methods, are a major concern in karst environments. This study examined flow cytometric (FCM) fingerprinting of bacterial cells in groundwater together with faecal indicator bacteria (FIB) at nine separate karst springs of varying catchment size over a 14 month period in order to assess whether such a technique can provide faster and more descriptive information about microbial pollution through such karst aquifer systems. Moreover, the data have also been evaluated with respect to the potential of using turbidity as an easy-to-measure proxy indicator of microbial pollution in a novel way. We argue that FCM provides additional data from which enhanced insights into faecal pollution sources and its fate and transport in such karst catchments can be gained. We also present valuable new information on the potential and limitations of turbidity as an indicator of faecal groundwater contamination in karst. FCM has the potential to become a more widely used tool in the field of contaminant hydrogeology.
... Most of this work has been done at a regional or landscape level (1:50,000 scale or greater) and covers a wide range of disturbances such as caused by agriculture, quarrying, mining, engineering and urban development projects (van Beynen, 2011). Some disturbance evaluations in karst areas have focused on specific karst environments or attributes such as karst aquifers and cave fauna (Drew, 1996;James, 1993) A holistic approach to evaluating karst disturbances was adopted by van Beynen and Townsend (2001). They used five categories (geomorphology, atmosphere, hydrology, biota and surface practices) and a total of 33 associated indicator attributes to measure and compare disturbances on karst landscapes. ...
... Land use changes have significant impacts on karst areas. Anthropogenic activities such as urbanization and development, deforestation, agriculture, ranching, livestock grazing, fire suppression practices, urban landscaping, landfills, waste-water discharge, sewage disposal and sewage and municipal water infrastructure can all change the nature of land surface and water resource interaction (e.g., Boyer and Pasquarell, 1999;Drew, 1996;Garcia-Fresca, et al., 2004;Harding and Ford, 1993;Parise and Pascali, 2003;Sauro, 1993;Wang et al., 2004;. Negative impacts such as soil degradation, groundwater salinization, increases in contaminant concentrations, degradation of water quality, ecosystem and biodiversity loss, and changes in aquifer storage, recharge, and water availability can result in karst regions as a result of land use changes. ...
... Parise and Pascali (2003) synthesize the worldwide causes of karst environment degradation and main consequential effects. Especially the passage from traditional agricultural practices (animal rearing and dairy farming) to modern intensive agriculture is the primary cause of karst landscape change and of negative implications for the hydrological properties of its surface (Drew, 1996). ...
... Land use changes have significant impacts on karst areas. Anthropogenic activities such as urbanization and development, deforestation, agriculture, ranching, livestock grazing, fire suppression practices, urban landscaping, landfills, waste-water discharge, sewage disposal and sewage and municipal water infrastructure can all change the nature of land surface and water resource interaction (e.g., Boyer and Pasquarell, 1999;Drew, 1996;Garcia-Fresca, et al., 2004;Harding and Ford, 1993;Parise and Pascali, 2003;Sauro, 1993;Wang et al., 2004;. Negative impacts such as soil degradation, groundwater salinization, increases in contaminant concentrations, degradation of water quality, ecosystem and biodiversity loss, and changes in aquifer storage, recharge, and water availability can result in karst regions as a result of land use changes. ...
... 长期以来, 国内外对磷素迁移传输及其污染控制研究多集中于地表径流过程 [2] ; 然而, 20 世纪 90 年代以后, 许多试验研究发现壤中流对磷素迁移有重要作用 [7] , 如在英国洛桑试验站长期土壤肥料试 验地(1843 年开始), Heckrath 和 Brookes 等对 65cm 下排水管中排出水分析发现, 水中磷素浓度很高, 占排 水中总磷含量的 66%-86%, 且以可溶的反应性无机磷(MRP)为主要成分 [8] . 研究证实, 随壤中水流输入 的磷素是导致湖泊和河流富营养化的重要营养物质来源之一 [9][10][11] ...
River network plain in Taihu Basin was selected as an experiment place, and triple duplication experiments had been carried out under artificial rainfall conditions to study the characteristics of phosphorus transfer from runoff of farmland. The results indicated that surface runoff was the main way of phosphorus losing from the agricultural field during artificial rainfall. The amount of losing phosphorus caused by surface flow and soil erosion of total phosphorus output accounted for 58.50% and 34.69% respectively, while that by interflow of total phosphorus output was only 6.81%. Particulate phosphorus was the primary pattern of phosphorus transfer which accounted for 60.73% of the total phosphorus losing. Inorganic phosphate was the primary pattern of dissolved phosphorus transfer. Compared with the particulate phosphorus, dissolved phosphorus can move more easily in the soil. Analysis of the characteristics of phosphorus transfer in surface runoff and interflow showed that soil could reduce the concentration of phosphorus when flows passed through it, in particular have obvious effect on reducing the concentration of TPP, up more than 80%. In addition, despite surface runoff was the primary way of phosphorus transfer in rainstorm-runoff process, in such a basin as Taihu, which has abundant rainfall, interflow is the main pattern at normal rainfall conditions, dissolved phosphorus transfer from interflow account for a large percentage of phosphorus loss, which has an important contribution to water environmental degradation of the region. Therefore it is of great significance to strengthen the research of dissolved phosphorus transfer for environment conservation.
... Land use changes have significant impacts on karst areas. Anthropogenic activities such as urbanization and development, deforestation, agriculture, ranching, livestock grazing, fire suppression practices, urban landscaping, landfills, waste-water discharge, sewage disposal and sewage and municipal water infrastructure can all change the nature of land surface and water resource interaction (e.g., Boyer and Pasquarell, 1999;Drew, 1996;Garcia-Fresca, et al., 2004;Harding and Ford, 1993;Parise and Pascali, 2003;Sauro, 1993;Wang et al., 2004;. Negative impacts such as soil degradation, groundwater salinization, increases in contaminant concentrations, degradation of water quality, ecosystem and biodiversity loss, and changes in aquifer storage, recharge, and water availability can result in karst regions as a result of land use changes. ...
... Subsurface karst features, such as caves and aquifers, are also easily impacted by human activity occurring both above and below the ground surface. Opening and closing cave entrances, waste from tourists, artificial lighting, and sediment compaction, just to name a few items, each negatively impact cave systems (Baker and Genty, 1998;Donahue, 1990;Gillieson, 1996;Gunn et al., 2000;Harding and Ford, 1993;James, 1993;Parise and Pascali, 2003;Silverwood, 2000), while agricultural, industrial, and municipal practices each contribute to degradation of karst aquifers and surface collapse (Arfib et al., 2000;Boulton et al., 2003;Drew, 1996;Loop and White, 2001;Sauro, 1993;Wood et al., 2002;Parise and Gunn, 2007). ...
Due to its high fragility, that derives from the intrinsic geological and hydrogeological characteristics, karst is extremely vulnerable to degradation and pollution. Although the carrying capacity of these natural environments is low, a variety of human activities is implemented on karst settings generating impacts at the surface and subsurface. The human-induced effects in karst can be assessed by applying a recently developed Karst Disturbance Index (KDI). The KDI consists of 31 environmental indicators contained within the five broad categories: geomorphology, hydrology, atmosphere, biota, and cultural. The purpose of this research is to apply the KDI to two distinct karst areas, West Florida, USA, and Apulia, Southeast Italy. Through its application, the utility of the index can be validated and other important comparisons can be made, such as differences in the karst legislations implemented in each region and the effect of time exposure to human occupation to each karst terrain. Humans have intensively impacted the karst of southeast Italy for thousands of years compared to only decades in west-central Florida. However, west-central Florida's higher population density allows the region to reach disturbance levels comparable to those reached over a longer period in Apulia. Similarly, Italian karst is more diverse than the karst found in west-central Florida, creating an opportunity to test all the KDI indicators. Overall, major disturbances for southeast Italy karst include quarrying, stone clearing, and the dumping of refuse into caves, while west-central Florida suffers most from the infilling of sinkholes, soil compaction, changes in the water table, and vegetation removal. The application of the KDI allows a benchmark of disturbance to be established and later revisited to determine the changing state of human impact for a region. The highlighting of certain indicators that recorded high levels of disturbance also allows regional planners to allocate resources in a more refined manner.
... The stored effluent then drained into the underlying carbonate karst aquifer. Drew (1996), working in the Burren country of western Ireland, investigated the threat of farm-related effluents on the underlying karst groundwater system. It was discovered that a large proportion of silage piles produced a potent form of effluent that greatly exceeds the other more commonly examined types of effluent in terms of its biological oxygen demand (B.O.D.) (Table 1). ...
There is an acknowledged lack of information available to managers of New Zealand's karst estate on the impacts of primary activities on these sensitive environments. A review of the international literature was undertaken to begin to address the issue. Subjects of particular interest were identified by Department of Conservation staff and included, in order of priority: forestry, agriculture and quarrying, followed by a second range of activities including landfilling, groundwater chemistry changes, urbanisation, cave climate and near-entrance vegetation change, and also conservation legislation. While there is a volume of literature on karst, it is largely devoted to the science of karst processes rather than the impacts of primary activities. In many cases the science is robust and the likely impacts of primary activity can be adequately assessed. In the future, improved communication by karst managers and researchers and the people living on, and in contact with karst landscapes on a daily basis will lead to better informed and directed research on the impacts of human occupancy on karst ecosystems.
... 8 In the European Union, approximately 30% of the land area is underlain by karstified limestone 9 and, where chemical monitoring data are absent, the intrinsic vulnerability of karst aquifers to pollution transfer from overlying agricultural land is assumed to be high due to rapid translocation of water from soil surfaces via karst features and conduit networks. 10,11 In Ireland, where approximately 19% of the landscape is underlain by karst, 10 there is a concern that P in groundwater from karst aquifers may contribute to poor ecology of adjacent surface waters. 12 Groundwater in Ireland is considered to be impaired and at "poor status" when an Environmental Quality Standard (EQS) of an annual mean concentration of 0.035 mg L −1 of total (molybdate) reactive P is exceeded and when the hydraulic load from that groundwater body exceeds 50% of a receiving surface water body that is at less than "good status". ...
The degree to which waters in a given watershed will be affected by nutrient export can be defined as that watershed's nutrient vulnerability. This study applied concepts of specific phosphorus (P) vulnerability to develop intrinsic groundwater vulnerability risk assessments in a 32km2 karst watershed (spring zone of contribution) in a relatively intensive agricultural landscape. To explain why emergent spring water was below an ecological impairment threshold, concepts of P attenuation potential were investigated along the nutrient transfer continuum based on soil P buffering, depth to bedrock and retention within the aquifer. Surface karst features, such as enclosed depressions, were reclassified based on P attenuation potential in soil at the base. New techniques of high temporal resolution monitoring of P loads in the emergent spring made it possible to estimate P transfer pathways and retention within the aquifer and indicated small-medium fissure flows to be the dominant pathway, delivering 52-90 % of P loads during storm events. Annual total P delivery to the main emerging spring was 92.7 and 138.4 kg total P (and 52.4 kg and 91.3 kg as total reactive P) for two monitored years, respectively. A revised groundwater vulnerability assessment was used to produce a specific P vulnerability map that used the soil and hydro-geological P buffering potential of the watershed as key assumptions in moderating P export to the emergent spring. Using this map and soil P data, the definition of critical source areas in karst landscapes was demonstrated.
... North-south underground linkages with velocities of 100-200 m hr )1 indicate a high degree of karstification, and rapid transfer Catchment and site location maps potential of contaminants from swallow holes to springs (Coxon and Drew 2000). Groundwater in this area has been identified as particularly vulnerable to agricultural contamination (Drew 1996). FS05 and FS08 are among a group of springs feeding the Fergus River upstream of Lough Inchiquin, a brown trout fishery lake that is of mesotrophic status (McGarrigle and others 2002) and has experienced sporadic algal blooms in recent years. ...
Transfer pathways of phosphorus (P) from soil to surface waters are the subject of much current research because of concerns about eutrophication. However, P transfer via groundwater discharge has received little attention. Temporal P changes at eight Carboniferous limestone karst springs from two catchments in western Ireland are examined. The eight springs were sampled fortnightly between June and October 1999 and thereafter monthly until February 2000. Each sample was analysed for total P (TP), total dissolved P (TDP) and dissolved reactive P (DRP). Total P exhibited some hydrological response at all springs (e.g. increase from 45 to 107gl–1) reflecting significant changes in particulate P (PP) (e.g. increase from 7 to 44gl–1) and dissolved organic P (DOP) (e.g. increase from 0 to 27gl–1), with DRP displaying greatest temporal stability. Greatest response to rainfall events occurred after the first major autumnal rains in September 1999, when there appeared to be dislodging of loosely bound PP and DOP, which was transported to groundwater. This response to the first autumnal rains probably reflects the hydrological switch where the catchments change from a soil moisture deficit to a soil moisture surplus situation. Daily autosampling demonstrated TP concentrations of up to 1,814gl–1 due to local pollution, highlighting the need to adopt storm event driven sampling rather than discrete sampling in karstic springs. Identification and management of springs in karst areas, with associated point recharge via swallow holes, presents an urgent and demanding challenge.
... Subsurface karst features, such as caves and aquifers, are also easily impacted by human activity occurring both above and below the ground surface. Opening and closing cave entrances, waste from tourists, artificial lighting, and sediment compaction, just to name a few items, each negatively impact cave systems (Baker and Genty, 1998;Donahue, 1990;Gillieson, 1996;Gunn et al., 2000;Harding and Ford, 1993;James, 1993;Parise and Pascali, 2003;Silverwood, 2000), while agricultural, industrial, and municipal practices each contribute to degradation of karst aquifers and surface collapse (Arfib et al., 2000;Boulton et al., 2003;Drew, 1996;Loop and White, 2001;Sauro, 1993;Wood et al., 2002;Parise and Gunn, 2007). ...
The karst disturbance index (KDI) consists of 31 environmental indicators contained within the five broad categories: geomorphology, hydrology, atmosphere, biota, and cultural. The purpose of this research is to apply the KDI to two distinct karst areas, west Florida, USA, and Apulia, Italy. Through its application, the utility of the index can be validated and other important comparisons can be made, such as differences in the karst legislations implemented in each region and the effect of time exposure to human occupation to each karst terrain. Humans have intensively impacted the karst of southeast Italy for thousands of years compared to only decades in west-central Florida. However, west-central Florida's higher population density allows the region to reach disturbance levels comparable to those reached over a longer period in Apulia. Similarly, Italian karst is more diverse than the karst found in west-central Florida, creating an opportunity to test all the KDI indicators. Overall, major disturbances for southeast Italy karst include quarrying, stone clearing, and the dumping of refuse into caves, while west-central Florida suffers most from the infilling of sinkholes, soil compaction, changes in the water table, and vegetation removal. The application of the KDI allows a benchmark of disturbance to be established and later revisited to determine the changing state of human impact for a region. The highlighting of certain indicators that recorded high levels of disturbance also allows regional planners to allocate resources in a more refined manner.
... Parise and Pascali (2003) synthesize the worldwide causes of karst environment degradation and main consequential effects. Especially the passage from traditional agricultural practices (animal rearing and dairy farming) to modern intensive agriculture is the primary cause of karst landscape change and of negative implications for the hydrological properties of its surface (Drew, 1996). The need to improve the typical poor traditional agriculture in the karstic areas of medium and high elevations, activated also in Murgia agricultural transformations more and more significant according to the availability of new techniques, with inevitable repercussions on the environment. ...
Groundwaters of the Murgia carbonate aquifer represent the main groundwater resource of the Apulia region (SE Italy). In the highlands (Alta Murgia) karst crops out in different forms and textures which have been preserved up to the 1970s: little evolved agriculture and sheep rearing produced only a marginal modification of the epikarst while a high degree of division into parcels by drystone walls helped in preserving soils from erosion. In the last years the original scenery of the Alta Murgia changed due to widespread transformations of surface karstic textures for agricultural purposes, with undeniable negative consequences on the hydrogeological balance, concerning both the infiltration and the runoff terms. Stone shattering led to flattening and deep alteration of a large part of the original karstic landscape and to demolition of drystone walls.In a study area of about 139 km2 located in the Alta Murgia, the comparison of aerial photos related to the period 1950–2001 indicated that stone shattering had occurred for about 42% of the area.The hydrological behaviour of the first soil layer of experimental parcels representing both shattered stone and natural karstic surface textures was analysed by using the numerical model Hydrus-2D with the aim of estimating the variation on infiltration rate due to stone shattering. Intensive field and laboratory measurements concerned soil texture, soil water content, pressure head, saturated hydraulic conductivity, pan evaporation and meteorological parameters.
... The heterogeneous structure of karst aquifers consists of a diffuse flow system in the rock matrix and a conduit flow system in solutionally enlarged karst voids (Atkinson 1977;Estrela and Sahuquillo 1997;Kiraly 1998), which combine to cause slow and fast water responses observed in karst spring hydrographs. Especially after precipitation events, karst groundwater is very susceptible to pathogen contamination because of point recharge to the karst conduits and little filtration within the system (Drew 1996;Ryan and Meiman 1996;Auckenthaler et al. 2002). During dry weather periods, however, when the diffuse (matrix) flow system is dominant, only low levels of contamination occur. ...
Rapid changes in spring water quality in karst areas due to rapid recharge of bacterially contaminated water are a major concern for drinking water suppliers and users. The main objective of this study was to use field experiments with fecal indicators to verify the vulnerability of a karst spring to pathogens, as determined by using a numerical modeling approach. The groundwater modeling was based on linear storage models that can be used to simulate karst water flow. The vulnerability of the karst groundwater is estimated using such models to calculate criteria that influence the likelihood of spring water being affected by microbial contamination. Specifically, the temporal variation in the vulnerability, depending on rainfall events and overall recharge conditions, can be assessed and quantified using the dynamic vulnerability index (DVI). DVI corresponds to the ratio of conduit to diffuse flow contributions to spring discharge. To evaluate model performance with respect to predicted vulnerability, samples from a spring were analyzed for Escherichia coli, enterococci, Clostridium perfringens, and heterotrophic plate count bacteria during and after several rainfall events. DVI was shown to be an indication of the risk of fecal contamination of spring water with sufficient accuracy to be used in drinking water management. We conclude that numerical models are a useful tool for evaluating the vulnerability of karst systems to pathogens under varying recharge conditions.
Cultural landscapes, which in the field of heritage studies and practice relates to caring for and safeguarding heritage landscapes, is a concept embedded in contemporary conservation. Heritage conservation has shifted from an historical focus on buildings, city centres, and archaeological sites to encompass progressively more diverse forms of heritage and increasingly larger geographic areas, embracing both rural and urban landscapes. While the origin of the idea of cultural landscapes can be traced to the late-19th century Euro-American scholarship, it came to global attention after 1992 following its adoption as a category of ‘site’ by the UNESCO World Heritage Committee. Today, cultural landscape practice has become increasingly complex given the expansion of the values and meanings of heritage, the influence of environmental challenges such as human induced climate change, technological advancements, and the need to better understand and interpret human connections to place and landscapes.
The aim of this handbook is to strike a balance between theory and practice, which we see as inseparable, while also seeking to achieve a geographical spread, disciplinary diversity and perspectives, and a mix of authors from academic, practitioner, management, and community backgrounds.
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In this chapter, the authors introduce policies relating to cultural landscapes in Latin America and the Caribbean. They present five case studies – all World Heritage listed properties – which together illustrate some of the diversity of approaches and challenges to identifying, caring for, and safeguarding landscapes in Latin America and the Caribbean. In the World Heritage system, this cultural landscape is classified as a ‘relict or fossil landscape’ and is representative of the memory of slavery in the Americas. The influence of Franco-Haitian culture persists in the toponymy, music, and traditions of eastern Cuba. The future focus of the Coffee Cultural Landscape of Colombia (CCLC) is in four major areas: education for competitiveness and strengthening of entrepreneurship in line with the values of the CCLC; promotion of tourism and community-based initiatives; financing for environmental sustainability; and the formulation of public policy for the construction, improvement, and conservation of housing using traditional techniques.
The anthropogenic activities and natural changes might cause side effects on fragile karst landscapes. A good knowledge of the complex interrelationships between external factors and karst landscape is the basis for proper conservation strategies. However, there is little empirical evidence on local resident’s perceived impacts on karst landscape in the world heritage sites. In this study, the multiple impacts of climate change and anthropogenic activity on karst landscapes were investigated in Guilin, a world heritage site, China. We conducted a questionnaire survey of residents and received 1006 valid responses in July 2020. The results showed that over 60.8% of respondents perceived the increased change of the karst landscape in the past two decades. Human production and living activity was regarded the primary reason of local karst landscape change, followed by the natural disaster and climate change. Assessing by 40 indicators of karst landscape disturbance, the karst landscape was disturbed moderately or significantly in Guilin. The significant and direct disturbances were quarrying/mining, industrial/petroleum spills, human-induced soil erosion, industrial activities, tour activities, and dumping refuse into sinks. Climate change also accelerated the degradation of karst landscape. This study contributes a research gap regarding systematic analysis of the pubic judgements of kart landscape change and its disturbances. The strategy linking physical-environmental properties to human perceptions of the landscape can be applied other ecosystem assessment and management in other regions and countries.
This chapter provides a review of the impacts of agriculture on karst terranes, and on management approaches to minimize such impacts. It discusses the range of agricultural activities with potential impacts on soil and water in karst regions, including deforestation, changes in grazing intensity and changes from pasture to tillage, application of fertilizers, and pesticides and storage of farm wastes. Case studies of impacts on soil and on water quantity and quality are presented, with a particular focus on water quality issues including suspended sediment, nitrate, phosphorus, pesticides, and microbial pathogens. The particular vulnerability of karst regions to such impacts is discussed, including the occurrence of point recharge in closed depressions and swallow holes, the thin, patchy soil cover found in many karst areas, the presence of epikarst and the occurrence of conduit flow within karst aquifers. Methods of risk evaluation are reviewed briefly and management strategies to minimize impacts of agriculture are discussed, including the use of Best Management Practices, community-based agri-environmental initiatives, and various legislative controls.
Karst environments have been impacted by human activity for thousands of years, ever since people started living in caves for shelter, needing building supplies and water. As human population has increased, so has its disturbance of the karst landscape. Quarrying, pollution, groundwater extraction, construction, and agriculture are the major culprits for disturbing both surface and subsurface karst. Ecosystems in this type of environment have been shown to be quite vulnerable to human activities. Methods to quantify this disturbance, such as the karst disturbance index, have been created to help resource managers formulate approaches to reduce this anthropogenic impact. In addition, models to measure karst vulnerability, in particular karst aquifers, have grown in number over the last two decades. When measuring human disturbance, it is important to consider matters of time and scale, as both will influence how and what data is collected.
Cyanobacterial bloom occured in Lake Gaoyang, Huangshi Dailizi and Shuangjiang Bridge of the backwater area of Xiaojiang River in Three Gorges Reservoir in late May of 2007. After the survey on the phytoplankton and water quality, it was found that cyanobacteria dominated the phytoplankton, taken up to the 81.43% of the total biomass, among which the Anabaena flos-aquaes was the dominance species. The heterocysts appearing in most species indicated that nitrogen fixation may occur. Low TN:TP ratio in April was that the heavy storm may trigger this nitrogen-fixation algal bloom. Phosphorus limitation was another characteristic, which is the result of the tremendous growth of phytoplankton. Lake Gaoyang may be the source place where algal bloom occured. Cyanobacteria moved downstream with the water flows, assembling at Huangshi Dailizi, where algal bloom was more than that in the Lake Gaoyang. As a result, total biomass and chlorophyll-a in Huangshi Dailizi was the highest among the sampling spots. Water velocity in Shuangjiang Bridge was slower due to the enlarged cross section downstream, offering a proper environment for the growth of cyanobacteria. Accompanied by the large amount of nutrients loads at Yunyang County, this may be the major reason of the detection of algal bloom in Shuangjiang Bridge.
Two turloughs on the east Burren limestones in County Galway were the subject of a study of current and recent management practices. Farmers with animals on each turlough were interviewed about stock type, stocking density, time of stocking and fertiliser application. Cattle were and still are the dominant stock, but average densities have increased by over 60% over 40 years. One turlough (Caherglassaun) has a history of fertiliser use, and stocking levels are more intense. There was no standard grazing time or stocking density for either turlough. Farmers often operated quite different regimes for the same turlough. The maximum length of any regime was almost seven months, the period without flooding. These results are discussed in relation to the designation of many turloughs as Candidate Special Areas of Conservation (CSACs). Flexibility in devising management plans for the turloughs is recommended.
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This study addresses the classification of grassland and heath communities found within the Burren uplands of Co. Clare and identifies threats to their integrity. Quadrats were taken on a range of sites, focusing on semi-natural, upland grassland and heath of conservation interest. Before analysis, the data set was divided into a heath group and a grassland group based on cover of dwarf shrubs. The data were analysed using TWINSPAN and canonical correspondence analysis. Within the grassland group, two main associations were found: the Sesleria caerulea–Breutelia chrysocoma association of lownutrient, calcareous, species-rich grasslands, and the Dactylis glomerata–Holcus lanatus association of more-mesotrophic grasslands. Within each group three sub-associations were identified. The heaths also fell into two main groups: one dominated by Dryas octopetala, and the other by Calluna vulgaris. The Dryas heath association formed three sub-associations, while the Calluna heaths formed three distinct associations, including associations of rare alpine heaths with Empetrum nigrum and Arctostaphylos uva-ursi. From direct ordination, significant environmental and management factors, such as altitude, soil depth and grazing pressure, were identified. Trends within the data set suggest a gradual increase in agriculturally favoured species with increased summer grazing. Abandoned and less-grazed areas are threatened by scrub and bracken encroachment.
The karst disturbance index (KDI) consists of 31 environmental indicators categorized within the five broad categories of geomorphology, hydrology, atmosphere, biota, and culture. This article discusses the application of the KDI to the rural karst region of Waitomo, New Zealand. Previous applications of the KDI measured disturbance to urban areas as delineated by geo-political boundaries while this study used a physical boundary of a small karst catchment. Such an approach ensures greater environmental specificity of measured disturbance levels compared to those determined according to arbitrary, politically defined areas. The study included a comparison of a local resource manager and a visiting karst expert's determinations of disturbance levels for the catchment. Overall, the Waitomo catchment was found to be moderately disturbed. The only significant, direct disturbances were deforestation and erosion; however, these lead to the indirect disturbance of cave biota, water quality and accelerated sedimentation of the catchment's waterways. We have a high degree of confidence in the validity of these results due to the ability to assess all of the applicable indicators in the index, and the consistency of scoring by both individuals who applied the index. The benefit of applying the KDI at the catchment level is the greater accuracy measuring disturbance as opposed to applying the index within geo-political boundaries that incorporate both karst and non-karst terrains. With disturbance data for a highly specific area, the Waitomo resource managers have the improved ability to effectively identify, target, remediate, and manage human disturbance of the karst landscape.
This paper examined groundwater and wetlands in the Shannon river basin in the context of implementation of the European water framework directive (WFD). The particular wetland example of turloughs (groundwater fed temporary lakes in karst areas) was examined in the context of defining river basin district boundaries and in the delineation of their catchment areas for risk assessment as required by Articles 3 and 5, respectively of WFD. Groundwater dependent terrestrial ecosystems such as turloughs are particularly challenging in terms of delineating their catchment areas for the purposes of risk assessment and implementation of measures. Turloughs are a habitats directive Annex I priority habitat, which occur mainly in Ireland and consequently, many turloughs in Ireland have been designated as special areas of conservation. Better understanding of such complex systems with high degrees of groundwater–surface water interaction will be required to ensure their protection in river basin management plans.
Karst environments, unique from other environments, require their own disturbance index. Karst resources are increasingly disturbed by a variety of processes related to social, physical, and economic factors. Recent studies have begun to qualify and quantify these disturbances, yet their focus has been limited to one or two factors such as biotic, geomorphic, or economic impacts. A more holistic approach, addressing economic, scientific, and cultural factors, is needed, to effectively assess the threats to karst areas. Currently, there is no efficient method to measure, compare, and contrast the disturbance of karst environments. We propose a hierarchal and standardized environmental disturbance index as a tool to measure regional impacts and highlight the areas of the karst system that require more protection or study. Addressed categories of disturbance include cultural, biotic, atmospheric, hydrological, and geomorphologic impacts.
Hillsborough County, Florida, is a karst region that is heavily urbanized, yet no study has been undertaken measuring the degree of human disturbance. Van Beynen and Townsend (2005) created a hierarchical and standardized disturbance index specifically designed for karst environments. To address the problem of determining human disturbance in the county, the above index was successfully applied and it was found that Hillsborough was highly disturbed (disturbance score of 0.69 of 1.0) because of its predominant urban and rural land use. Furthermore, the application of the index allowed for its refinement and the highlighting of environmental aspects in need of remediation such as soil compaction, deforestation, disturbance of archaeological sites, and the expanding urban footprint. Several minor issues arose during the application: the need for broader indicator descriptions that encompass a variety of scenarios, the need for a revised water quality indicator, inadequate data on sinkholes, and a lack of data for species richness and species population density. The utility of the index to resource managers arises from emphasizing certain areas of the environment that require immediate attention and determining temporal changes in environmental quality. Future application of the index requires potential retooling of the biota indicators, tightening of scoring descriptions for certain indicators, and further examination of the scale at which the index can be applied.
The Burren plateau of northwest Co. Clare is extensively karstified, surface water being confined to short reaches of ephemeral streams, seasonal turloughs and drainage from adjacent non-carbonate rocks. Annual precipitation is c. 1500mm of which c.980mm is not evapotranspired. Recharge is rapid, either via concentrated inputs from sinking streams at the boundary between Namurian and Visean rocks or via diffuse inputs over the limestone plateau. The limestone aquifer is characterised by low storage and rapid transmission of water. Discharge at the periphery is via a few large springs - one set of which in the valley of the upper River Fergus drains more than a third of the area. There are also important submarine springs draining the northern and western flanks of the Burren. The hydrogeomorphological history of the Burren is complicated, encompassing the decay of a surface fluvial network and the effect of changes in base level. Problems of water supply and in the maintenance of high standards of water quality are current and are likely to increase in the near future.
Between 1981–1991, 4% of the Burren area (1371ha) was reclaimed under the Programme for Western Development. Most of the reclamation was intensive and the land is being used to produce silage. Although more efficient and intensive agriculture is now possible, there has been a corresponding loss of environmental variety as scrub, semi-natural grassland, limestone pavement and ancient field boundaries have been replaced by uniform grassland fields. The great increase in fertiliser and silage usage may pose a threat to groundwater quality in the area.