The effects of geology and land use on the export of phosphorus from watersheds

The export of total phosphorus from 34 watersheds in Southern Ontario was measured over a 20-month period. The annual average export for igneous watersheds (i.e. those of the Canadian Shield) that were forested was 4.8 mg m⁻² yr⁻¹, significantly different from the average (11.0 mg m⁻² yr⁻¹) for watersheds that included pasture as well as forest. Similarly, on sedimentary rock, the mean export from forested watersheds (10.7 mg m⁻² yr⁻¹) differed significantly from those with forest and pasture (28.8 mg m⁻² yr⁻¹). The differences between watersheds of different geology but similar land use were also highly significant.Additional data from the literature supported our conclusions. Other forested igneous watersheds of plutonic origin averaged 4.2 mg m⁻² yr⁻¹ of total phosphorus exported: forested igneous watersheds of volcanic origin, however, averaged 72 mg m⁻² yr⁻¹. The overall average export from each type of watershed as classified by geology and land use was very similar to that for the same classification found in our study.The effects of agriculture and urbanization were to greatly increase the total phosphorus exported. Wide ranges of values probably reflect the intensity of land use.     

Impact indices for grazing actions

Proposals for animal grazing actions on federal lands in the United States are subject to both permit requirements and the environmental impact assessment (EIA) process. Such actions are often controversial due to the detrimental effects of overgrazing on vegetation, soil, riparian zones, water quality, and wildlife habitat. This paper highlights the potential negative environmental impacts of livestock grazing on rangelands in the western United States, identifies techniques or models that could be used to determine the severity of these impacts, and enumerates several indices which have been used to summarize environmental data in relation to decision‐making processes. Nine such indices, along with several additional ones which could be reasonably developed, are described herein. These indices, used either individually or in a composite format, could serve as reasonable bases to identify vulnerable rangelands, provide a framework for impact prediction, target monitoring efforts to identified rangelands, facilitate the determination of sustainable grazing practices, select mitigation measures, and document decisions for new or renewal grazing permits.     

The new era of the livestock production in Mongolia: Consequences on streams of the Great Lakes Depression

Mongolia, a landlocked country of the Central Asian plateau, is experiencing a significant modification of herding practices coupled with an increase in livestock numbers. These modifications lead to increasing impacts of grazing on the Mongolian steppes with major consequences on the waterbodies. We researched the impacts of grazing intensity on the streams of the Great Lakes Depression in northwestern Mongolia. We assessed the level of watershed and stream bank erosion and the type of vegetation structure. We calculated the livestock densities per watershed and linked them to the stream water discharge through a new metric (I_CU). I_CU was created as a function of cattle unit density and water discharge, having water discharge at a stream section reflecting its location in the drainage and therefore accounting for the surface area drained upstream. We measured also the major nutrients in the stream water and researched the causalities between the grazing and the impairment of watersheds and streams. Our results suggest that the increase of livestock numbers is reaching beyond the grassland and affecting the stream ecosystem. Two major impacts were highlighted by this study, 1) the extensive watershed and stream bank erosion and 2) the increase in concentration of suspended particles and orthophosphate in stream systems. When compared with past values from literature, our results show recent eutrophication of the streams compared to the pre-liberalization of the herding activity in Mongolia (before 1991). Consequently the continued uncontrolled increase of livestock numbers could threaten the conservation of the Mongolian waterbodies, with notable consequences on the life of the nomadic population of the Central Asian Plateau.     

Impact of climatic fluctuations and land use change on runoff and nutrient losses in rural landscapes

Results on the influence of land use and climatic changes on nutrient losses in the Porijõgi river catchment, south Estonia, are presented. The main tendency in land use changes is a significant increase in abandoned lands (from 1.7% in 1987 to 12.5% in 1994), and a decrease in arable lands (from 41.8 to 22.5%). Significant climatic fluctuations were observed from 1951–1994. Warmer winters (increase from −7.9 to −5.8°C from 1950–1994) and a change in the precipitation pattern have influenced the mean annual water discharge. This results in more intensive material flow during colder seasons and decreased water runoff in summer. Changes in water discharge and land use are also reflected in the mean annual runoff of total inorganic nitrogen (TIN) and total-P which decreased from 15.6 to 2.7 kg N ha⁻¹ yr⁻¹ (83%) and 0.32 to 0.21 kg P ha⁻¹ yr⁻¹ (34%), respectively during this period. However, nutrient losses from the forest subcatchment (upper course) did not change significantly. In contrast, the mean annual runoff of water, organic matter (after biological oxygen demand: BOD₅), TIN, total-P and SO₄ from cultivated subcatchments showed a significant decrease.     

Impacts of land-use change on mammal diversity in the upper reaches of Minjiang River, China: Implications for biodiversity conservation planning

The objective of this study was to assess land use change and the related biodiversity variations in the forest landscape of the upper reaches of Minjiang River, China. We examined temporal changes of land use at different periods. Remotely sensed images taken in 1974, 1986 and 2000 were rectified and classified based on the physiognomic characteristics of the vegetation. We applied landscape pattern metrics based on landscape composition, the shape and size of patches and patch isolation. We also calculated the suitable area for mammals in the upper reaches of Minjiang River and biodiversity of medium and large-sized mammals with Genera-Family index (G-F index). As a result of timber harvesting and increase of population, the forest area decreased and other land-use types increased. The suitable area for mammals decreased by 81,339 ha from 1974 to 2000, about 21.55% of the habitat in 1974. The number of medium and large-sized mammal species had decreased from 31 to 26, with G-F index decreased by 0.11, about 20% that of 1974. It can be concluded that landscape change and suitable habitat play an important role in protecting mammal diversity.     

Factors affecting changes in landscape diversity in rural areas of the Fagus crenata forest region of central Japan

We compared landscape diversity in a primary forest site and a coppice forest site in rural area of the Fagus crenata forest region of central Japan. We focused on the factors affecting landscape diversity, with special reference to land ownership, and the relationship between changes in landscape diversity and the spatial distribution of landscape elements. We were able to identify two patterns that led to increased landscape diversity in the study sites. In the first, which was most apparent in the primary forest site, increased diversity resulted primarily from an increase in the number of landscape elements. In the other, which was seen in the coppice forest site, increased diversity resulted from a decrease in the difference between the numbers of grid squares dominated by each landscape element while the number of landscape elements remained unchanged. Land ownership also had different implications for the increase of landscape diversity. The changes in the Contagion Index, which decreased in private land and increased in the national forest, showed that private land contains many small patches while the landscape of the national forest consists of a few large, contiguous patches. Thus, an evaluation of changes in landscape structure requires measuring a variety of indexes in addition to the diversity.     

Spatio-temporal patterns of birch regrowth in a Western Norwegian treeline ecotone

The study investigates spatio-temporal patterns of birch regrowth in a mountain valley in which intensive livestock grazing was formerly practised. Vegetation changes were identified through analysis of three sets of aerial photographs. The results of GIS analyses, one-way ANOVA and PCA showed that regrowth patterns are complex. In the early phase of succession, grazing history has a strong impact on where new forest establishes, both at a distance from the seasonal farmsteads where grazing intensity prior to abandonment was highest, and close to previously existing forest. Sprouting is most likely to be the dominating regeneration strategy in this early phase. In a later phase of succession, the impact of grazing history on forest distribution patterns decreases, as exemplified by the increasing distance from existing forest. The largest amounts of birch forest then establish in warm locations with moderate moisture. Protection against wind appears to be important for birch establishment.     

Effects of land use changes on herbivores of masai mara ecosystem

The Narok District has undergone rapid changes in land use patterns from nomadic pastoralism to a sedentary and farming lifestyle. In this study we describe wildlife and livestock numbers and past and present land‐use patterns in three group ranches from 1975 to 1997. The purpose of this paper is to examine the effect of land‐use changes on herbivore populations. Research methods included observation and interpretation of satellite imageries and aerial photographs, field checks, participant observation and secondary data. Results indicate that human settlement areas have increased significantly (x² = 11.475, 3 df, p=0.001), while natural vegetation area has decreased insignificantly (x² = 0.2, 3 df, p = 0.777) between 1975 and 1997. Trend analysis indicated an increase in livestock numbers (601100 + 843 year; r² = 0.127; P=0.018), a decrease in wildlife numbers (953400–632 year; r² = 0.272; P = 0.036) and an overall increase in large herbivore numbers (155000+211 year; r² = 0.150; P =0.043). The information gained in this study can be used in the process of zoning the dispersal areas for different land uses. Also, if supported by a further study it can establish the optimum sustainable land use(s) around Masai Mara Reserve, that can assure the coexistence of man and wildlife.     

土地利用类型视角下重庆市主城区生态 控制区区划及生态廊道构建研究

科学合理地构建生态网络并划定生态控制区能够有 效提升城市韧性,保护生物多样性。以重庆市主城区为研究对 象,采用形态学空间分析(MSPA)和景观指数法,对土地利用 类型中的耕地、林地、水体和草地进行网络要素组成统计和景 观格局分析,并提取耕地、林地2类重要的土地利用类型,依 据斑块面积和斑块重要性指数进行重要性分级,将级别高的斑 块作为生态源地。而后,基于最小累积阻力模型(MCR)构建 生态廊道,通过重力模型完成了生态廊道的重要性分级。结果 表明：1)重庆市主城区中耕地与林地面积之和占比达69.86% 且景观破碎化程度较为严重;2)应对耕地和林地斑块进行分级 规划保护,划分耕地与林地的生态控制区;3)重庆市主城区共 计构建出281条廊道,其中林地型廊道28条、耕地型廊道253 条;4)通过识别生态廊道的土地利用类型,根据重要性分级结 果对生态控制区进行调整,最终识别和划定了重庆市耕地控制 区和林地控制区。研究结果可为重庆市主城区生态控制区的划 定、调整及生态网络的构建提供依据和启示。     

The influence of coniferous afforestation on lowland farmland bird communities in Ireland: different seasons and landscape contexts

Current governmental policy in Ireland is encouraging afforestation, 80% of which is likely to consist of exotic conifer species, in low-lying agricultural areas. Whereas most studies of bird diversity in forest/farmland mosaic landscapes have focused on high quality woodland remnants in a hostile agricultural matrix, this study has considered the influence of man-made plantations in a less intensively farmed context. Bird communities of three lowland agricultural landscapes (each 2000 ha in area) with intermediate or low levels of coniferous forest cover (33% or 8% approximately) were sampled in winter and summer. Though total abundance and species richness of birds of farmland habitats in the partially forested and open sites did not differ, the presence of trees in the surrounding landscape did influence abundance of some common species such as Blue Tit Parus caeruleus, Robin Erithacus rubecula and Blackbird Turdus merula. In winter, species composition of farmland habitats with and without hedgerow trees differed between forested and open landscapes. Also, the abundance of certain species varied between farmland adjacent to and remote from forest edges, in both seasons. In these landscapes, coniferous plantations did not greatly affect the mainly generalist farmland bird community, either positively or negatively. However, if the proportion of land-use occupied by forestry were to increase, reducing the available hedgerow habitat and forest edge/area ratio, diversity and abundance of declining farmland bird species might be negatively affected.     

Over-parameterised, uncertain 'mathematical marionettes' - how can we best use catchment water quality models? An example of an 80-year catchment-scale nutrient balance

The Integrated Catchment Model of Nitrogen (INCA-N) was applied to the River Lambourn, a Chalk river-system in southern England. The model's abilities to simulate the long-term trend and seasonal patterns in observed stream water nitrate concentrations from 1920 to 2003 were tested. This is the first time a semi-distributed, daily time-step model has been applied to simulate such a long time period and then used to calculate detailed catchment nutrient budgets which span the conversion of pasture to arable during the late 1930s and 1940s. Thus, this work goes beyond source apportionment and looks to demonstrate how such simulations can be used to assess the state of the catchment and develop an understanding of system behaviour. The mass-balance results from 1921, 1922, 1991, 2001 and 2002 are presented and those for 1991 are compared to other modelled and literature values of loads associated with nitrogen soil processes and export. The variations highlighted the problem of comparing modelled fluxes with point measurements but proved useful for identifying the most poorly understood inputs and processes thereby providing an assessment of input data and model structural uncertainty. The modelled terrestrial and instream mass-balances also highlight the importance of the hydrological conditions in pollutant transport. Between 1922 and 2002, increased inputs of nitrogen from fertiliser, livestock and deposition have altered the nitrogen balance with a shift from possible reduction in soil fertility but little environmental impact in 1922, to a situation of nitrogen accumulation in the soil, groundwater and instream biota in 2002. In 1922 and 2002 it was estimated that approximately 2 and 18 kg N ha^− 1 yr^− 1 respectively were exported from the land to the stream. The utility of the approach and further considerations for the best use of models are discussed.     

Identifying the spatial mixture distribution of bird diversity across urban and suburban areas in the metropolis: A case study in Taipei Basin of Taiwan

This study utilized a finite mixture distribution model (FMDM) to identify the distribution of bird diversity in urban and suburban areas of the Taipei basin. The spatial patterns of Shannon's diversity index were estimated using Sequential Gaussian simulation (SGS) with bird investigation data. To validate the results of FMDM, bird groups were classified by two-way indicator species analysis (TWINSPAN) based on bird presence-absence records. The probabilities exceeding FMDM's cut-off values for suburban bird communities were obtained from SGS realizations. The results showed that bird diversity in the Taipei basin could be comprised of two-component mixture distributions for urban and suburban bird communities, respectively. The FMDM bird diversity classifications fit the TWINSPAN groups of urban and suburban species. The spatial maps of bird diversity in the study area provide evidence that a metropolis can cause changes in the spatial characteristics of bird communities at the landscape level. Furthermore, the bird diversity and land use maps could be useful for future conservation and urban planning in Taipei Basin, particularly urban green spaces and wetlands. The maps could also be utilized in network planning of green belts or corridors for ecological conservation.     

Changes in farming system and population as drivers of land cover and landscape dynamics: The case of enclosed and semi-openfield systems in Northern Galicia (Spain)

In this study, we aimed to document the changes in the bocage and semi-openfield landscapes of Northern Galicia from the second half of the 20th century and analyse the factors driving landscape changes. In particular, we examined (1) the dynamics of the field systems characteristics in these landscapes and (2) the interrelations with changes in dominant land cover, population and farming systems (in terms of productive structure, land use system and farming practices) dynamics. The picture of the1950s showed mainly semi-openfield field systems and nucleated villages that extended through valleys in the lowland, with banks in rough coastline sectors. In the highlands we found enclosed fields and scattered hamlets interspersed within large extensions of scrubland. In between both systems, a transitional area with mixed characteristics appeared. In 2000, the transitional area expanded from the former semi-openfields and banks areas, while the highlands still retain the enclosed character. The dominant land cover has experienced significant changes throughout the area, following an increase in woodland. A reorientation of the farming system was observed, a shift in which cropland lost importance with regard to grassland, the use of scrubland became marginal and forestry increased. The decrease in the number of farms and livestock shows decline in agricultural activity. This can be closely related to changes in dominant land cover and cropping patterns. Despite recent changes, this area still retains characteristic features of traditional landscapes such as the spatial pattern of field systems and ancestral cultural practices (e.g. extensive grazing of the scrubland).     

LOCAL KNOWLEDGE OF SWIDDEN FARMERS AND CHALLENGES FOR SUSTAINABLE LAND USE: LESSONS FROM A WATERSHED MANAGEMENT PROJECT IN NORTHERN LAOS

In Laos, located in mainland Southeast Asia, shifting cultivation has been one of the important means of livelihood, in terms of food security as well as religious and cultural anchorage, for local communities in a number of areas, especially in upland areas in the country. In Pakbeng District, Oudomxay Province, northern Laos, due to the implementation of various land and forest management policies and a village relocation and consolidation program, local communities were restricted from access to the forests and faced a shortage of agricultural lands. After facing difficulties in securing sufficient lands, the local farmers used the forests in a destructive manner. The author of this article was engaged with the Community-based Watershed Management Project, as a program director of an environmental NGO and tackled challenges to achieve a land and forest management system suitable for land use by local communities. The NGO attempted to apply an alternative approach to incorporate swidden farmers’ land use system into official land and forest management institutions.     

Relationships between urbanization and the oak resource of the Minneapolis/St. Paul Metropolitan area from 1991 to 1998

Urbanization was associated with loss and transformation of the oak forest in the Twin Cities (Minneapolis and St. Paul) metropolitan area (TCMA) over a recent 7-year interval. Between 1991 and 1998, urbanization increased based on several indicators: population density, area of developed land, and area of impervious surface—total impervious area and area within three classes of increasing degree of imperviousness (protected, affected, and degraded). We quantified relationships between changes in urbanization and changes in several parameters describing the oak forest at the scale of ecological subsection. Increased total and affected impervious area were strongly correlated with decreased area of oak forest when changes of the urbanization indicators and oak were expressed as percentages of the subsection area. Relationships were reversed when changes were expressed as percentages of the 1991 values. Increased population density was strongly correlated with increased loss in numbers and increased isolation of oak patches, but weakly correlated with loss of oak forest area. This is the first study to quantify relationships between changes in urbanization and changes in a specific forest cover type. Our results demonstrate complexities of urbanization impacts on a metropolitan forest resource, and highlight the importance of selected variables, spatial and temporal scales, and expressions of change when quantifying these relationships.     

Local and landscape scale variables impact parasitoid assemblages across an urbanization gradient

Urbanization is a major driver of land cover change worldwide, yet little is known about how urbanization affects beneficial arthropod communities. This study examined how local and landscape scale variables associated with urbanization influenced parasitic Hymenoptera abundance and diversity in residential and commercial properties along a rural to urban landscape gradient in Wisconsin. At a landscape scale, 300 m surrounding sites, land cover percentages were calculated for five cover classes: impervious cover, forest, grassland, agriculture, and urban green space. In addition, habitat diversity (Simpson's index) was calculated for the landscape surrounding study sites. At a local scale (within the boundaries of an individual property), flower diversity, flower area, tree density, and hardscape were measured and related to parasitoid abundance and diversity. During 2006 and 2007, parasitoids were sampled twice a month June-August using yellow sticky cards. Parasitoid abundance was a positive function of flower diversity, a local scale variable. The positive relationship between parasitoid abundance and flower diversity only occurred in areas containing high to moderate levels of urban development, suggesting parasitoids locally benefited from the increased availability of floral resources in urban but not rural sites. Parasitoid diversity decreased as impervious cover increased in the surrounding landscape. Parasitoid diversity decreased by approximately 10% in highly urbanized sites relative to rural sites, a pattern driven by several parasitoid families not detected in urban sites. These results suggest conservation strategies that focus on landscape variables at multiple scales can play an integral role in preserving beneficial arthropods across urban landscapes.     

Spatial and temporal dynamics of land use pattern in Turkey: A case study in İnegöl

Recognition and understanding of landscape dynamics as a historical legacy of disturbances are necessary for sustainable management of forest ecosystems. This study analyzed forest dynamics and spatial–temporal changes in land use/land cover pattern in a sub-temperate like alluvial forest land with 1778 km² area along the Eagan Sea coast of Turkey (İnegöl). This area is studied by comparing Landsat images from 1987 to 2001 and evaluated with spatial analyses of forest cover type maps from 1972, 1983, 1993 to 2004 using GIS. The study investigated temporal changes of spatial structure of forest conditions over the period using Fragstats™.The results showed that the forested areas increased both in between 1972 and 1993 years (3.3%) and between 1987 and 2001 years (6.7%). In terms of spatial configuration, İnegöl forests are generally fragmented in the latter periods due to intensive forest utilization, illegal use, expansion of settlements and infrastructural development in the lowlands. Land use pattern significantly changed over time depending on a few factors such as unregulated management actions, social pressure and demographic movements. In conclusion, land use changes have developed in favor of forestry over time between 1972–1993 and 1987–2001. The study revealed that demographic movements have a minor effect on landscape dynamics. Both spatial and temporal changes and the factors affecting these changes should be determined for developing sustainable management of forest resources.     

Evaluation of an ecological land type classification system, Natchez Trace State Forest, western Tennessee, USA

In an effort to aid future research and forest management decisions, we incorporated data on forest type, soils and topography into a geographic information systems (GIS)-based ecological land classification system for Natchez Trace State Forest (NTSF) in western Tennessee. The area is still recovering from the effects of cultivation, logging, forest clearing and grazing during the 1800s and early 1900s, but the data indicated that most stands now contain sawtimber-sized trees after more than 50 years of secondary succession. Our analyses showed that forest types were not randomly associated with soil characteristics or topography. For example, the most heavily gullied lands were strongly associated with pine forests while hardwoods were more associated with upland soils and certain types of sideslopes. Mature hardwood stands, which were deemed to be of the greatest conservation value, were classified into eight ecological land types based on soil type, aspect, orientation and topographic setting for further study. When these land types were evaluated with respect to data on forest composition and environmental conditions collected in the field, we found that the variables used to derive the eight classes were important in influencing floristic patterns. It was, however, clear that the classes themselves imperfectly captured patterns of overstory community composition for a number of reasons. Thus, while land types provide a potentially valuable management tool, their utility and successful implementation are dependent upon a recognition of their inherent limitations.     

山地城市空间的三维集约生态界定

以山地城市空间三维集约特质为切入点,提出保护城市内外的河川、分水岭、林地、陡坡、冲沟、滑坡等不适于城市建设的生态敏感地域,以自然生态敏感地域与人工生态绿化区的精细组合为基础,构建山地城市建设空间的三维生态界定体系。在界定系统的有机整合过程中实现集约生态效益,在优化城市土地利用的同时,营造良好的城市空间环境品质。     

Lichen biota in the low land of the Ob basin

The article reviews the lichen diversity in the low land of the Ob basin based on the data published by the author and other specialists. So far, species diversity has reached 430 taxonomic units from 102 genera and 42 families. There are data about the distribution of certain lichen species for the main types of habitat and substrates with in cenosis. The largest variety is shown in communities of dark coniferous forests and mixed forests with declining aspens in the tree layer (215 species), of forested fens (161 species), and inundated forest cenosis (100 species). The least variety is found in ground slope communities (13 species) and phytocenoses of transition moors (12 species).