• A Simple Method for Predicting the Consequences of Land Management in Urban Habitats

      Young, Christopher; Jarvis, Peter (Springer New York, 2001)
      Land management in urban areas is characterized by the diversity of its goals and its physical expression in the landscape, as well as by the frequency and often rapidity of change. Deliberate or accidental landscape alterations lead to changes in habitat, some of which may be viewed as environmentally beneficial, others as detrimental. Evaluating what is there and how changes may fit into the landscape context is therefore essential if informed land-management decisions are to be made. The method presented here uses a simple ecological evaluation technique, employing a restricted number of evaluation criteria, to gather a spatially complete data set. A geographical information system (GIS) is then used to combine the resulting scores into a habitat value index (HVI). Using examples from Wolverhampton in the United Kingdom, existing real-world data are then applied to land-management scenarios to predict probable landscape ecological consequences of habitat alteration. The method provides an ecologically relevant, spatially complete evaluation of a large, diverse area in a short period of time. This means that contextual effects of land-management decisions can be quickly visualized and remedial or mitigating measures incorporated at an early stage without the requirement for complex modeling and prior to the detailed ecological survey. The strengths of the method lie in providing a detailed information baseline that evaluates all habitats, not just the traditional “quality” habitats, in a manner that is accessible to all potential users—from interested individuals to professional planners. (Springer Verlag)
    • Compulsory Land Acquisition in Ghana - Policy and Praxis

      Larbi, Wordsworth Odami; Antwi, Adarkwah; Olomolaiye, Paul (Amsterdam: Elsevier, 2004)
      Compulsory land acquisition powers have been used extensively in Ghana since colonial times, as the main means of the state's access to land for development. The underlying principle is supremacy of the state over people and their private property, and is aimed at providing land for public and social amenities, correcting economic and social inefficiencies in private market operations and providing greater equity and social justice in the distribution of land. The paper analyses compulsory acquisition practice in Ghana in the light of these principles. It argues that few of the presumed principles have been met. Rather compulsory land acquisition has resulted in adverse socio-economic consequences including in landlessness, poverty and heightened tension in state-community relationship. The paper advocates for a new legal and institutional environment for employing compulsory acquisition powers.
    • Inter-relationships between soil-protecting land use systems, recreation and tourism on agricultural landscapes in Lithuania

      Jankauskas, Benediktas; Jankauskienė, Genovaitė; Fullen, Michael A. (Siauliai University, Lithuania, 2008)
      Soil de­gra­da­tion by soil erosion is evident on the hilly- undula­ting landsca­pe, when com­mon land use systems, containing tilla­ge crops, are practised by land ow­ners. Results of long-term field investigations enab­le the proposal of specific erosion‑resistant land ma­na­ge­ment systems, which enable us to loca­lize and sta­bilize erosion processes on are­as most vulne­rable to soil erosion. It is fe­a­sible to im­ple­ment soil-protecting land use systems (i.e. erosion- re­sistant crop rota­tions and long-term pe­rennial grasses) de­signed for fields of vary­ing size, slope gradient and soil texture. The­se agro- environmental aims can be integrated with rural tourism, thus enabling re­ha­bilita­tion of de­gra­ded land and im­proving the socio- economic situation of rural villages. Matching specific soil tilla­ge ope­ra­tions with intensity of fertiliza­tion permits further re­tarda­tion of soil erosion intensity. The proposed vision of the modern Lithua­nian villa­ge is thus to re­com­mend new activities for local land owners and to promote sustainable and environmentally- friendly economic de­ve­lopment
    • Measuring urban habitat fragmentation: an example from the Black Country, UK

      Young, Christopher; Jarvis, Peter (Springer Netherlands, 2001)
      The processes of urbanisation have left a fragmented mosaic of habitat patches of varying size, shape and character with the result that from location to location the number and quality of contacts between patches varies considerably. Traditional measurements of this habitat fragmentation, and its converse, connectivity, have rarely looked at the landscape as a whole but instead have simplified it to specific landscape subsets, or else have looked at area-to-area relationships through generalising the landscape into homogeneous pixels or grids. In this paper the character of the whole landscape is examined at scales appropriate to the spatial variability of the urban environment. Using a direct measurement of patch-to-patch contact all contacts between all patches are examined and the relationship between all contiguous and connecting habitats is quantified. This is further refined to look at connections between patches of different quality, a measure that highlights the adverse effects of urbanisation as a whole on landscape connections between quality habitats. (SpringerLink)
    • Relationships between soil organic matter content and soil erosion severity in Albeluvisols of the Žemaičiai Uplands

      Jankauskas, Benediktas; Jankauskienė, Genovaitė; Fullen, Michael A. (Lithuanian Academy of Sciences, 2007)
      This article analyses relationships between soil erosion severity and soil organic matter (humus) content. The paper describes approaches to assess cumulative soil loss due to the combined action of natural (geological) and accelerated (human induced) soil erosion on Eutric Albeluvisols in Lithuania. Evaluation of soil erosion severity helps us understand which segments of the landscape are susceptible to erosion and therefore require soil conservation. The study also evaluates changes in soil organic matter content in relation to erosion severity. Factors considered in evaluating soil erosion severity included the existing genetic soil horizons remaining after soil erosion processes, the estimated thickness of lost soil and slope inclination. The estimated depth of soil loss due to the combined action of natural and accelerated soil erosion varied from 0.1–0.8 m on the undulating topography of the Žemaičiai Uplands. Erosion rates increased with slope steepness. Therefore, natural soil fertility (as indicated by spring barley yields) decreased by 21.7, 39.7 and 62.4% on slopes of 2–5°, 5–10° and 10–15°, respectively, compared with flat land. Crop yield was strongly negatively correlated (r2 = 0.790, P < 0.001, n = 138) with erosion severity and strongly positively correlated (r = 0.922; P < 0.001, n = 80) with soil organic matter content.
    • Soil erosion and changes in the physical properties of Lithuanian Eutric Albeluvisols under different land use systems

      Jankauskas, Benediktas; Jankauskienė, Genovaitė; Fullen, Michael A. (Taylor & Francis, 2008)
      The investigations aimed to: 1) evaluate water erosion rates on undulating slopes in Lithuania under different land use systems; 2) study changes in soil physical properties on the differently eroded slopes; and 3) better understand relationships between soil physical properties and soil erodibility. Research data were obtained on loamy sand and clay loam Eutric Albeluvisols located on the undulating hilly relief of the Zcaronemaiccaroniai Uplands of Western Lithuania. The results of 18 years of water erosion investigations under different land use systems on slopes of varying steepness are presented. Attention is focused on changes in soil physical properties in relation to soil erosion severity. Measured water erosion rates in the field experiments were: 3.2-8.6 m3 ha-1 yr-1 under winter rye, 9.0-27.1 m3 ha-1 yr-1 under spring barley and 24.2-87.1 m3 ha-1 yr-1 under potatoes. Perennial grasses completely prevented water erosion, while erosion-preventive grass-grain crop rotations (67% grasses, 33% cereal grains) decreased soil losses by 75-80% compared to the field crop rotation, containing 17% tillage crops (potatoes), 33% grasses and 50% cereal grains. The grain-grass crop rotation (33% grasses and 67% cereal grains) decreased soil erosion rates by 23-24%. The percentage of clay-silt and clay fractions of arable soil horizons increased, while the total soil porosity and moisture retention capacity decreased with increased soil erosion. Phytocenoses, including sod-forming perennial grasses and grass-grain crop rotations, led to changes in the physical properties of eroded soils; soil bulk density decreased and percentage total porosity and moisture retention capacity increased. The grass-grain crop rotations increased the water-stable soil structure (measured as water-stable soil aggregates) by 11.03 per cent units and sod-forming perennial grasses increased aggregate stability by 9.86 per cent units compared with the grain-grass crop rotation on the 10-14° slope. Therefore, grass-grain crop rotations and sod-forming perennial grasses decreased soil erodibility and thus could assist both erosion control and the ecological stability of the vulnerable hilly-undulating landscape.
    • Soil erosion and conservation in northern Europe

      Fullen, Michael A. (Sage, 2003)
      Soil conservation policies are suggested at national, regional and local levels, including adoption and modification of several Australian, European and North American policies. The Australian Landcare system and programmes of the US Natural Resources Conservation Service (NRCS) are particularly informative. Several European initiatives are promising models, including the strategies of the Danish Land Development Service (Hedeselskabet) and the Icelandic Soil Conservation Service (Landsgraedsla Rikisins). The Erosienormeringsprojekt of South Limburg (The Netherlands) is a coordinated and integrated soil conservation project and seems a particularly useful model for future soil conservation in northern Europe. Several best management practices for soil conservation are identified. These include the promotion of soil conservation by a properly funded and relatively well known soil conservation service and full mapping, monitoring and costing of erosion risk by national soil survey organizations. A participatory approach to soil conservation should be adopted, involving farmers and interested members of the public, and there should be a 'cost share' partnership between government and farmers in funding conservation work on farms. Rational land-use policies need to be developed, such as the promotion of 'set-aside' on erodible soils, grass strips on arable slopes and buffer strips in riparian zones. Education programmes are necessary to actively inform the public on the importance of soil as a resource. These schemes should particularly encourage 'land literacy' among participants. It is imperative that the broader societal benefits of effective soil conservation are recognized, such as its potential contribution to habitat creation, biodiversity and carbon sequestration.
    • Urban gully assessment in São Luis City (Maranhão State), Brazil, using penetrometer data and soil properties

      Guerra, Antonio J. T.; Sathler, R.; Mendes, S.P.; Silva, S.L.S.; Guerra, T.T.; Araujo, I.H.M.; Lima, F.S.; Fullen, Michael A.; Booth, Colin A.; Mendonca, J.K.S.; et al. (International Association of Geomorphologists, 2006)
      This paper investigates soil erosion assessment in São Luis City, reporting an ongoing programme of field measurements (penetrometer measurements and gully monitoring), topsoil sampling and laboratory analyses. From the database, it is evident that the urban sector of São Luis is very prone to gully erosion, especially where land use promotes land degradation. This research work is part of the larger European Union Project ‘BORASSUS’, which investigates soil erosion assessment and rehabilitation in 10 different countries, including Brazil. In our case, we are the only country investigating urban gully erosion. Therefore, this paper presents some preliminary results, both in terms of penetrometer measurements and soil properties, and we make some initial conclusions regarding the four studied gullies, which are situated in São Luis City, Maranhão Island (2º19’9”- 2º51’S; 44º1’16”-44º19”37” W). In order to achieve the research objectives, we have carried out both field and laboratory work, so that penetrometer data could be related to laboratory data. On each one, we selected different parts, around each gully, to take three penetrometer measurements, to calculate the site mean. On completion, we calculated the mean for the whole gully, taking into account the mean for each site. We collected topsoil (0-10 cm) samples to determine selected soil properties in the laboratory (particle size distribution, particle density, bulk density and porosity), using EMBRAPA (1997) protocols. Although most penetrometer studies are related to agricultural situations, for this study we have used penetrometry to assist our understanding of gully evolution and behaviour. The whole study area shows a high sand content and low silt and clay contents; textures being sandy loams. In 60% of analysed soil samples, the silt content is higher than the clay content, confirming the higher detachability and transportability of fine sand and silt. Penetrometer measurements are related to soil compaction, due to people walking on tracks around the gullies. Those values showed direct association with parameters related to vegetation cover. We can conclude that this area presents high sensitivity to erosion, expressed by high bulk density values, high fine sand and silt contents, low clay content and low porosity.