Agricultural Landscape Pattern Research Articles

Agrivoltaics and landscape change: First evidence from built cases in the Netherlands

The need to advance energy transition has arisen from the global challenge of climate change. Shifts to renewable energy sources, such as solar energy, are crucial for reducing carbon emissions and mitigating climate change. The use of agrivoltaics—the combination of food and renewable energy production with photovoltaic technology—is gaining scientific attention. Agrivoltaics is a type of multifunctional energy landscape and thus reduces land use conflicts between energy and food production. However, while agrivoltaics has begun to proliferate at a global scale, the associated landscape changes have so far received little attention. This knowledge gap is critical, as there is clear evidence that landscape change often contributes to low levels of acceptance of solar power installations. To address this gap, this study examines landscape changes brought by agrivoltaic installations in the Netherlands. Four representative built cases were examined making use of key landscape change indicators extracted from the literature and fieldwork. The study revealed varying degrees of landscape change across the examined cases. Changes in the agricultural landscape pattern and openness emerged as prominent landscape changes. Changes in crop type and in historical linear landscape structures—often associated with the implementation of conventional solar power plants—were not identified. Policy attention to the siting and design of agrivoltaic systems in the landscape is needed to positively influence social acceptance of this relatively novel solution and thereby advance energy transition.

Effect of agricultural landscape pattern on the qualitative food web of epigaeic arthropods in low hilly areas of northern China

Under the macro background of global change and sustainable development, the sustainable and healthy development of agricultural landscapes is crucial for human well-being. Formulating targeted protection measures based on biodiversity conservation is currently a hot topic and challenge. Our study focused on Jianping County, a typical hilly area in northern China, to understand the impact of regional agricultural landscape patterns on qualitative food webs. We calculated food web parameters by constructing predator-pest qualitative food web matrices and compared the differences in food web structure characteristics under different agricultural landscape patterns. By using function regression method, we established landscape indices and food web parameter models. The results showed that the average number and community structure of predatory natural enemies and pests varied across different agricultural landscape patterns, but the common groups were similar. Maintaining a proportion of 30–40 % non-crop habitats is optimal for the stability of qualitative food webs. Different landscape elements have varying regulatory effects on the structure of qualitative food webs, and the food web parameter model can explain these effects more directly. Specifically, the Landscape Shape Index (LSI) is significantly positively correlated with Generality (G), while the Contagion Index (CONTAG) is significantly negatively correlated with vulnerability (V). We propose that in low hilly areas, where non-crop diversity is the primary source of heterogeneity, promoting measures for non-crop habitats through landscape planning will help maintain the richness of epigaeic arthropods and the stability of qualitative food webs. This research is of great significance in promoting ecological control and sustainable development of agroecosystems in low hilly areas.

Agricultural space function transitions in rapidly urbanizing areas and their impacts on habitat quality: An urban–Rural gradient study

Agricultural space functions in rapidly urbanizing areas experience rapid transition with urban–rural development process, leading to habitat fragmentation and degradation. Previous studies focused more on impacts of agricultural landscape patterns on habitat quality at the regional scale, ignoring transition processes of agricultural space functions and functional combinations under an urban–rural gradient perspective and their different impacts on habitat quality. This study constructed a holistic framework oriented by four main agricultural space functions, including production, living, ecological, and landscape culture functions, to map transition characteristics of agricultural space function combinations in the main urban area of Hangzhou, a typically rapidly urbanizing area in China, from 2000 to 2019 under the urban–rural gradient. Impacts of these transition processes on habitat quality were further investigated.The results showed that spatiotemporal differences in variations of various agricultural space functions leaded to urban–rural gradient changes in the transition of agricultural space function combinations. From the urban development area to the urban–rural transition area and rural development area, the dominant output type was the single function area, while the dominant input type was the comprehensive function area, composite function area, and single function area, respectively. Areas with decreased habitat quality were mostly concentrated around urban construction land, and they had the highest proportion in the urban development area. All transition types in the urban development area had a negative impact on habitat quality, while the transition process from a more complex function combination to a simpler one in the urban–rural transition area and rural development area had a greater positive impact, and areas transformed from the lagged development area to other functional combinations also produced a positive impact. These findings provide ideas for rational spatial decision-making about limited agricultural resources in rapidly urbanizing areas.

Impacts of Policy-Driven Transformation in the Livelihoods of Fishermen on Agricultural Landscape Patterns: A Case Study of a Fishing Village, Island of Poyang Lake

The agricultural landscape patterns of fishing village have undergone visible transformations in recent decades. Scholars pay less attention to fishermen with diverse livelihoods. Therefore, it is necessary to sort out the changing characteristics of fishermen’ livelihoods and agricultural landscape patterns under different policy periods. We use in-depth interviews, remote sensing technology, and mathematical analysis to systematically study the changes in fishermen’s livelihoods and in agricultural landscape patterns in a typical fishing village. The results show that policy have profoundly affected fishermen’ livelihoods. Livelihood transformation have altered local land use practices, which had a direct impact on agricultural landscape patterns. The livelihood of fishermen has changed from diverse to single, and their cropping structure were gradually becoming simpler and more specialised. After grazing ban and comprehensive fishing ban, many fishermen migrated to towns and cities, it accelerated the loss of population in the fishing village, which caused the amount of abandoned land increasingly. Left-behind fishermen became rice farmers by contracting abandoned paddy fields. The expanses of abandoned land and bamboo woodland had increased, which caused agricultural landscape patterns gradually becoming fragmented, heterogeneous and complex.

Flowering agricultural landscapes enhance parasitoid biological control to Bemisia tabaci on tomato in south China.

Agricultural landscape pattern may enhance biocontrol services by supporting parasitoid populations, including parasitoids of Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae). In this study, we selected four landscape types in Yunnan province, in south China, which were characterized by flower fields, mountain, river, and urban areas as their main elements. We then carried out systematic surveys in tomato fields found within each landscape type, to determine the diversity, occurrence, and parasitism rate of parasitoids. We found that parasitoids from the genus Encarsia and Eretmocerus were the main natural enemies present, and the most abundant species were recorded in the flower and the mountain landscapes. Also, Encarsia formosa (Hymenoptera: Chalcidoidea) formed the highest relative abundance regardless of the landscape type. We also found that the population density of B. tabaci in flower landscapes was the lowest than that in other landscape types. During the main activity period of B. tabaci, the parasitism rate in the flower landscape was higher than that in other landscape types. Our findings showed that the occurrence of B. tabaci was relatively mild in the flower landscapes. The landscape type was also beneficial to parasitoids as it enhanced their parasitism rate. Therefore, agriculture environmental schemes should consider increasing the size of flower fields in the surrounding landscape to enhance the sustainable control of B. tabaci by the natural agricultural ecosystem.

Dynamic changes and transitions of agricultural landscape patterns in mountainous areas: A case study from the hinterland of the Three Gorges Reservoir Area

Dynamic changes and transitions of agricultural landscape patterns in mountainous areas: A case study from the hinterland of the Three Gorges Reservoir Area

Regulation of dynamics and densities of whitefly Bemisia tabaci by agricultural landscapes in south China

Agricultural landscape patterns can affect the population dynamics of pest insects. We selected four landscapes (flower field, mountain, river and urban) based on principal components analysis in Yunnan Province, south China. Through systematic investigation carried out in tomato fields, we intended to clarify the population dynamics and densities of Bemisia tabaci under different landscape types. During the main activity period of B. tabaci, the population densities of B. tabaci nymphs in tomato fields in the river and the urban landscape types were the highest compared to the other landscape types; the population densities of female adults in tomato fields in the river landscape type were also the highest. While the population densities of B. tabaci nymphs and female adults in the flower landscape type, no more than five individuals (ind.) 100 cm−2 leaf in both years, were the lowest. The density of B. tabaci nymphs in the middle position of tomato plants was higher than those in the other positions, while the density of adults in the upper position of tomato plants was higher, regardless of landscape types. Our findings showed that the population growth of B. tabaci can be easily controlled by the flower landscape type.

A study on the evolution mechanism of agricultural landscape pattern of Dadu River Valley in Danba Region

Taking the Dadu River Basin in the Danba area of Ganzi Prefecture, Sichuan Province as the research area, based on the 2013 and 2016 Landsat8 remote sensing images, the temperature vegetation drought index (TVDI) method is used to divide the Dadu River dry valley into 6 arid gradient regions. Using ArcGIS10.5 software and Fragstats4.2 software to calculate the landscape pattern index of different arid gradient areas in different years, combined with the survey results of agricultural policies, development models, and agricultural landscape patterns in key regions, analyze the evolution of agricultural landscape patterns under different drought gradients. The results show that, except for other forestlands, the degree of landscape fragmentation is decreasing year by year on the gradient of light and moderate drought, and the degree of spatial heterogeneity is higher. On the gradient of extreme drought, the degree of landscape fragmentation is higher, and the degree of spatial heterogeneity is lower.

Dynamic role of grasslands as sources of soil-dwelling insect pests: New insights from in silico experiments for pest management strategies

Sustainable pest control strategies hinge on the knowledge of movement ecology within the agricultural landscape where contrasted habitat qualities intermingle, thereby influencing arthropod dispersal. Hence, habitat manipulation in space and time can be a lever for action to control pests with regard to landscape compositional constraints. In this study, we examined the role of grassland arrangements in field colonisation by soil-dwelling pests within a dynamic agricultural landscape, and discussed the implications for pest management with a focus on wireworms. For this purpose, we proposed a framework combining (i) a spatially explicit and mechanistic model describing the pest population dynamics in both aerial and soil compartments involved along its life cycle, and (ii) spatiotemporal representations of various landscape contexts. We addressed the role of grassland in plot history, in plot neighbourhood, or in both history and neighbourhood. Our results show that species with a short life cycle are more responsive to changes in land use, and that the neighbourhood effect strongly relies on dispersal mechanisms (random vs directed movements). We also highlight how the arrangement of grassy landscape elements in space and time can mitigate crop infestation by soil-dwelling pests, thereby emphasizing the relevance of managing grassland regimes. Once informed by critical pest life traits, our approach opens avenue for the exploration of the spatiotemporal land use manipulation meant for pest management. Future research consists in the exploration of suppressive patterns in simplified but realistic agricultural landscapes, generated under agronomic constraints at the farm or landscape scales.

Regulating effect of agricultural landscape pattern on ecological pest control by natural enemies.

It's well known that regional agricultural landscape pattern can significantly regulate the relationship between plants, herbivorous insects and natural enemies. The improvement of the ecosystem services of regional agricultural landscape pattern has profound impacts on pest control, which has received much interests in current landscape ecology and pest control studies. This review systematically summarized the impacts of agricultural landscape pattern, as well as its succession on the diversity and ecological pests control of important natural enemies. From the perspective of different natural enemies, the impacts of agricultural landscape pattern on natural predators, parasi-toids, beneficial microorganisms and its ecological pests control functions were all recapped. We outlined crop spatial distribution and vegetation habitat management strategies. This review could provide useful insights in improving the ecosystem services of natural enemies in agricultural landscape based on the vegetation habitat management, and offer theoretical support for regional ecological agriculture in response to the strategy of 'chemical pesticide reduction application'.

Identifying win–win situations in agricultural landscapes: an integrated ecosystem services assessment for Spain

European agricultural landscapes are facing contradictory phenomena in that some areas are experiencing unsustainable land-use intensification while others are being abandoned. Specifically, agricultural intensification is increasing resulting in numerous negative environmental impacts on European soils, water and biodiversity; increased crop ecological footprints; and creation of social conflicts and inequalities. Within this context, we mapped and assessed ecosystem services from Spanish agricultural landscapes to identify ecological and economical win–win situations that could provide good examples of sustainable landscape management. We aim to spatially identify gaps and areas of overlap of ecological and economic values of ecosystem services at the national scale for Spanish agricultural landscapes. Additionally, we analyse possible connections among social concerns and preferences related to environmental issues and ecosystem services with economic and ecological values of local agricultural landscapes. First, we quantified and mapped the economic value of crop production at the national level. Second, we mapped the ecological value of agricultural landscapes based on the “high nature value farming” index. Third, we explored the spatial correlations between economic and ecological values to identify major agricultural landscape patterns at the national level and specific win–win situations at the local level. Fourth, we conducted a public survey of the Spanish population about environmental concerns and their preferences towards ecosystem services. Fifth, we analysed the links among the social concerns and preferences with the ecological and economic values of agricultural landscapes at the national level. Our results allow us to better understand the main landscape patterns and help develop more balanced management strategies. For instance, the results show how current landscape management in Spain is polarized between areas with high economic values and areas with high ecological performance. The maps produced also allow the identification of agricultural landscapes with high economic and ecological values that can be used as good examples for sustainable landscape management. Additionally, the public survey revealed that environmental concerns of the Spanish population and the importance the population places on agricultural ecosystem services received very low scores. The results from this study show that the possibility of balancing and reconciling the supply of ecological and economic values from agricultural landscapes exists in practice. The results help identify areas in Spain where actions should be taken to enhance sustainable landscape planning at the national level. Among the analysed environmental concerns of the Spanish population, the three environmental concerns that had the lowest scores are those that are tightly linked to the type of action needed to shift towards more sustainable agroecological systems. Finally, we discuss how complex interactions among ecosystem services should become part of the planning strategies for new sustainable landscape management at the national level.

How measures of agricultural landscape patterns are affected by crop rotation dynamics

Landscape patterns have been measured as a fundamental part of landscape ecology, especially with increasing computational power and availability of landcover data. Among the challenges associated with landscape measurement is identifying the appropriate scale of application, both temporal and spatial. Measurement of landscape patterns in highly-dynamic landscapes is especially challenged by temporal scale selection. This short communication focuses on how landscape pattern measurements vary in response to normal variability in a highly-dynamic landscape For a small agricultural landscape with known crop rotation dynamism sequences, a simulation model provided 30 years of crop rotations. These 30 different landscapes were measured with landscape pattern measurements and the variability of the measurements was assessed. Almost half of the measurement values were outliers, and 12 of the 30 years had at least one outlier landscape pattern measurement value, even though the basis of landscape change was a normative agricultural practice. For a consistent but dynamic landscape, some landscape measurements or simulation years had high variability, demonstrating that inferences from highly-dynamic landscapes need to be based on fine-resolution time steps. The application of landscape pattern measurements continues to be a common method in landscape ecology, and temporal dimensions are key to detecting change and what might be causing or responding to that change. The temporal resolution of change implies that highly-dynamic landscapes require more-frequent sampling, and that comparisons for agricultural landscapes over long time periods requires more than a single temporal endpoint.

农业景观异质性对生物多样性与生态系统服务的影响研究进展

PDF HTML阅读 XML下载 导出引用 引用提醒 农业景观异质性对生物多样性与生态系统服务的影响研究进展 DOI: 10.5846/stxb201806211354 作者: 作者单位: 河南大学黄河中下游数字地理技术教育部重点实验室;河南大学环境与规划学院,河南大学教育科学学院,河南大学黄河中下游数字地理技术教育部重点实验室;河南大学环境与规划学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31600374，41771202）；河南省教育厅科学技术研究重点项目（16A180022）；河南省博士后科研项目（2015049） Impact of agricultural landscape heterogeneity on biodiversity and ecosystem services Author: Affiliation: Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions,Ministry of Education,Henan University;China;College of Environment and Planning,Henan University;China,,Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions,Ministry of Education,Henan University;China;College of Environment and Planning,Henan University;China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:农业景观是人类生活所需资料的最主要来源地，农业景观及其提供的生物多样性和生态系统服务是影响人类福祉的最主要因素之一。系统梳理了景观异质性变化对生物多样性和生态系统服务影响的相关研究，总结指出：（1）农业景观格局变化会强烈的影响着区域生物多样性和生态系统服务，但总体上更关注了空间异质性，对于时间和功能异质性的研究仍需加强；（2）尺度效应、大尺度上景观背景的差异、种间差异、营养级联效应等会对景观异质性和生物多样性、生态系统服务间的关系产生显著的、综合的、交互的影响效应。未来区域农业景观中如何通过景观构建和管理措施的施行来确保生物多样性与生态系统服务供给的持续稳定仍需进一步加强以下内容的研究：景观异质性变化在时间上和功能上的影响效应及其阈值的探讨；跨尺度、多因素、多物种类群与多生态系统服务的综合及其交互作用；不同生物类群和不同生态系统服务间的权衡；景观异质性提高与有效生境面积下降及其引起的生物随机丧失间的权衡等问题。 Abstract:Biodiversity and ecosystem services, a frontier and hotspot of international ecology and geography research, are key to realizing the healthy development of regional ecosystems. The well-being and survival of humanity depend upon the stability and sustainability of services provided by the agricultural landscape. This study systematically reviewed research on the effects of landscape heterogeneity on biodiversity and ecosystem services. We found that changes in the agricultural landscape pattern strongly impact regional biodiversity and ecosystem services. However, previous studies have focused more on spatial heterogeneity; research on the temporal and functional heterogeneity of landscapes still needs to be strengthened. In addition, the scale effects, differences in the large-scale landscape context, interspecific differences, and trophic cascade effects have significant, comprehensive, and interactive effects on the relationships between landscape heterogeneity and biodiversity and ecosystem services. In the future, research on how to ensure a stable and sustainable supply of biodiversity and ecosystem services through the methods of landscape reconstruction and agricultural landscape management at the regional scale should be further strengthened. Specifically, four potential limitations to further expansion must be addressed, including the effects of temporal and functional heterogeneity on biodiversity, ecosystem services and their thresholds at the landscape scale; the cross-scale, multi-factor, multi-species, and multi-scale integration and interactions; the trade-offs of different biological groups and different ecosystem services; and the trade-offs between improving landscape heterogeneity and decreasing the effective habitat area, as well as the loss of biodiversity caused by declining habitat area. 参考文献 相似文献 引证文献

Agricultural landscape pattern and agricultural tourism potential of Nevsehir

Agricultural land being shaped depending on soil, climate and land structure, and consist of various size which vary from thousands of acres of land where a particular crop is grown to smaller formal gardens. Agricultural landscape is a sample of transition from natural landscape to cultural landscape, and it has emerged where people began growing crops for economic purposes. Besides the production of agricultural products, agricultural landscapes also have ecological, economic and social impacts such as soil protection, cultural green texture and creating aesthetic appearance, creating a living environment for the wildlife and contributing to tourism. Agrotourism, by combining agriculture and tourism, offers new sources of income for farmers. In this context, in recent years agricultural tourism is becoming increasingly important within the framework of sustainable tourism. In this study, distribution and parceling forms of agricultural landscapes that shaped the agricultural landscaping pattern of Nevsehir have been revealed by field survey, and rural settlement plan was created by specifying the characteristics of agricultural settlement types. Then, the potential of agricultural tourism, which one of the nature-based tourism activities that support the development of rural areas in the region has been assessed. Also possible applicable models for Nevsehir were put forward. As a result, viniculture in Nevsehir province, which has an important share in the regional economy, is important in terms of agricultural tourism. However, the economic problems experienced by the producers and the low incidence of the vineyard affects the viniculture culture negatively. In this context, agricultural tourism is important in terms of supporting and strengthening rural development in research area.

Tree species diversity and spatial distribution patterns on agricultural landscapes in sub-humid Oromia, Ethiopia

Trees are important components of agricultural landscapes in different parts of Ethiopia, and information on their type, diversity and distribution in sub-humid agroecologies is essential for designing interventions. A study was conducted to evaluate tree diversity and their spatial patterns in agricultural landscapes under different land use categories in four selected sub-humid sites in Western Oromia, Ethiopia. Tree inventory was conducted on 100 homesteads (19 ha), 18 crop lands (35 ha) and 11 grazing lands (5.5 ha) belonging to 100 randomly selected households. A total of 82 tree species were identified: 67 in the homesteads, 52 in the crop lands and 29 in the grazing lands. The density of trees varied from 68 trees per ha in crop lands to 801 trees per ha in homesteads. Diversity indices revealed that homestead was the most diverse with Shannon index of 2.42, and Simpson index of 0.84. The density of trees among the tree communities in the four sites varied from 133 in Bako Tibe to 476 in Jima Arjo, but not any one of the sites had more diverse tree community as revealed by the Renyi diversity profiles analysis. The three dominant tree species in the agricultural landscapes were Eucalyptus camaldulensis, Vernonia amygdalina and Cordia africana. Pearson correlation analysis showed that high tree species density, richness and diversity had high association with homesteads than with crop lands and grazing lands. It also revealed significant positive correlations between land size and evenness, and latitude and evenness whereas there were significant negative correlations between family size and Shannon diversity index, and land size and tree density. The majority (81.6%) of the trees were established through plantation and only 18.4% were regenerated naturally. The proportion of planted trees varied from 68% in Gobu Seyo to 94.1% in Guto Gida. The study showed that agricultural landscapes harbour high diversity of tree species with a spatial pattern, and increasing the tree cover with focus in the crop lands is essential for improved resilience of the agricultural systems and for circa-situm conservation of biodiversity.

The Spatial Pattern of Teritory on The Landscape-Dwelling Community Juruan Laok Village East Madura

The Madurese community is known as an individual, independent and subsistent corn farming community, identified as having three main territories: residential territory, open space territory and agricultural landscape territory. The distance between clusters of distant residential causes is referred to as individual society as well as independent. The dependence of life on crops causes the distance of dwelling with the agricultural landscape so close that it is called subsistence society. Land-based economic morality, due to the persistence of maintaining spatial territory. So the fundamental question of research is how the third spatial pattern of territory in the village of Laok Madura Madura? The strategy used is ethnography, with qualitative research design. The main data collection methods were in-depth interviews, no open questions, with typical case sampling techniques in four occupancy based on five criteria: civitas, activity, shelter pattern, agricultural landscape pattern and artifacts existence of crop storage object. Internal validation in the form of observation, measurement and architectural documentation, caused by the characteristic of ethnic sub-ethnic of Madura, so that the head of village is not a source of internal validation, but the participant as the owner of the dwelling. The analysis is done by comparing with anthropological-architectural concept, human space concept, also with related theme study. The results obtained at least found the embodiment of the concept of spatial patterns called habitat. The concept of a spatial pattern called habitat consists of: place, environment and landscape. The arrangement of the three forms a hierarchical bubble that places in the environment, while place and environment are in the landscape. Referring to the concept of architectural-anthropological, the hierarchy of these three elements is referred to as: habitat.

Spasial ruang pada hunian masyarakat peladang-muslim desa juruan laok madura timur

Jagung dan Islam adalah identitas kultur etnis Madura, sehingga dikenal sebagai masyarakat peladang-muslim.Mereka juga dikenal sebagai masyarakat mandiri, subsistensi dan sangat bergantung pada lanskap agrarisnya.Penelitian sebelumnya banyak membahas spasial hunian-kekerabatan dan spasial hunian-kesakralan terutama padahunian Madura perantauan. Penelitian ini berbeda karena berusaha memahami spasial lanskap-hunian padamasyarakat peladang jagung di desa Juruan Laok Madura Timur, pada lingkup mikro. Rancangan penelitian bersifatkualitatif dengan strategi etnografi. Pengumpulan data primer utama berupa wawancara mendalam dengan tak-tikpertanyaan terbuka dan sampling bertujuan. Validasi internal menggunakan observasi, pengukuran dan dokumentasiarsitektural, mengingat sifat subsistensinya dan kepala desa bukan narasumber utama. Diambil empat kasus hunianterpilih berdasarkan civitas, aktivitas, pola hunian, pola lanskap pertanian dan eksistensi obyek penyimpanan panen

Spatiotemporal dynamics of climate and agricultural landscape patterns in Xinjiang, China (2000-2015)

This study integrated remote sensing, geographic information system, landscape ecology, and spatial analysis, and is based on meteorological data and four remote sensing images (2000-2015). The aim of this study was to analyse climate trends and spatiotemporal changes in agricultural landscape patterns, and calculate agricultural ecosystem service value (AESV) in Xinjiang, China. In addition, correlation analysis further enabled the quantification of agricultural landscape pattern changes in response to climate change. Results showed that temperature and precipitation registered a fluctuating ascending trend in most areas of Xinjiang. Landscape diversity and fragmentation increased during the same period. AESV showed a trend of gradual increase, the waste disposal and the water retention are the most important ecological functions. Besides, agricultural landscape pattern significantly correlated to climate and the effect of precipitation on agricultural landscape patterns has been greater than the effect of temperature during 2000-2015.

Exploring spatially varying and scale-dependent relationships between soil contamination and landscape patterns using geographically weighted regression

Landscape pattern is an important determinant of soil contamination at multiple scales, and a proper understanding of their relationship is essential for alleviating soil contamination and making decisions for land planners. Both soil contamination and landscape patterns are heterogeneous across spaces and scale-dependent, but most studies were carried out on a single scale and used the conventional multivariate analyses (e.g. correlation analysis, ordinary least squared regression-OLS) that ignored the issue of spatial autocorrelation. To move forward, this paper examined spatially varying relationships between agricultural soil trace metal contamination and landscape patterns at three block scales (i.e. 5 km × 5 km, 10 km × 10 km, 15 km × 15 km) in the Pearl River Delta (PRD), south China, using geographically weighted regression (GWR). This paper found that GWR performed better than OLS in terms of increasing R square of the model, lowering Akaike Information Criterion values and reducing spatial autocorrelation. GWR results revealed great spatial variations in the relationships across scales, with an increasing explanatory power of the model from small to large block scales. Despite a few negative correlations, more positive correlations were found between soil contamination and different aspects of landscape patterns of water, urban land and the whole landscape (i.e. the proportion, mean patch area, the degree of landscape fragmentation, landscape-level structural complexity, aggregation/connectivity, road density and river density). Similarly, more negative correlations were found between soil contamination and landscape patterns of forest and the distance to the river and industry land (p < 0.05). Furthermore, most significant correlations between soil contamination and landscape variables occurred in the western PRD across scales, which could be explained by the prevailing wind, the distribution of pollutant sources and the pathway of trace metal inputs.

Local and landscape drivers of predation services in urban gardens.

In agroecosystems, local and landscape features, as well as natural enemy abundance and richness, are significant predictors of predation services that may result in biological control of pests. Despite the increasing importance of urban gardening for provisioning of food to urban populations, most urban gardeners suffer from high pest problems, and have little knowledge about how to manage their plots to increase biological control services. We examined the influence of local, garden scale (i.e., herbaceous and arboreal vegetation abundance and diversity, ground cover) and landscape (i.e., landscape diversity and surrounding land use types) characteristics on predation services provided by naturally occurring predators in 19 urban gardens in the California central coast. We introduced sentinel pests (moth eggs and larvae and pea aphids) onto greenhouse-raised plants taken to gardens and assigned to open or bagged (predator exclosure) treatments. We found high predation rates with between 40% and 90% of prey items removed in open treatments. Predation services varied with local and landscape factors, but significant predictors differed by prey species. Predation of eggs and aphids increased with vegetation complexity in gardens, but larvae predation declined with vegetation complexity. Smaller gardens experienced higher predation services, likely due to increases in predator abundance in smaller gardens. Several ground cover features influenced predation services. In contrast to patterns in rural agricultural landscapes, predation on aphids declined with increases in landscape diversity. In sum, we report the relationships between several local management factors, as well as landscape surroundings, and implications for garden management.