Simple Landscape Research Articles

Quantum support vector data description for anomaly detection

Abstract Anomaly detection is a critical problem in data analysis and pattern recognition, finding applications in various domains. We introduce quantum support vector data description (QSVDD), an unsupervised learning algorithm designed for anomaly detection. QSVDD utilizes a shallow-depth quantum circuit to learn a minimum-volume hypersphere that tightly encloses normal data, tailored for the constraints of noisy intermediate-scale quantum (NISQ) computing. Simulation results on the MNIST and Fashion MNIST image datasets, as well as credit card fraud detection, demonstrate that QSVDD outperforms both quantum autoencoder and deep learning-based approaches under similar training conditions. Notably, QSVDD requires an extremely small number of model parameters, which increases logarithmically with the number of input qubits. This enables efficient learning with a simple training landscape, presenting a compact quantum machine learning model with strong performance for anomaly detection.

Landscape discourse of the Northern villages in Contemporary Vietnamese films (in the case of ‘Bến không chồng’ of Luu Trong Ninh and ‘Cuộc đời của Yến’ of Dinh Tuan Vu)

Through analysing the cinematic language, this essay wants to find out if there is a stereotype in the representation of the Northern village landscape in the films Bến không chồng (Luu Trong Ninh) and Cuộc đời của Yến (Dinh Tuan Vu) or not. From there, this research will show that that stereotype expressed a sense of nostalgia for and created regimes of truth about the Northern village. The essay also studies the discourse overlapping in these two films about the same historical period, with the same theme about women’s misery. This writing will point out that despite filming about the same landscape, Bến không chồng presents a sad, gloomy landscape; on the contrary, Cuộc đời của Yến shows a beautiful but simple landscape like in a tourism promotional video. Then, the author will give her opinions on the reasons for that discourse overlapping.

How far do forest container mosquitoes (Diptera: Culicidae) invade rural and urban areas in Japan? - Simple landscape ecology with comparison of the invasive Aedes ecology between native and invasive ranges.

The distribution of container mosquitoes in relation to distances from forests was studied in temperate Japan. Mosquito larvae were collected between May and September in 4 years from tree holes, bamboo stumps, riverine rock pools, and artificial containers; sampling ranged spatially from the mountain forest across the deforested plain developed as agriculture and urban areas to the seacoast. Although tree holes, bamboo stumps, and artificial containers existed throughout the deforested plain area, 10 container species of 6 genera were found virtually only within 5 km from the nearest forest edge. Worldwide invasive Aedes albopictus (Skuse) and Aedes japonicus (Theobald) of Asian origin showed unique occurrence patterns different from other container species and from each other. Ae. japonicus was dominant in artificial containers in and near the forest but minor in forest natural containers and only occurred within 5 km from the forest. Ae. albopictus was minor in the forest irrespective of container types but not bound to the forest and dominant in natural and artificial containers throughout rural and urban areas. The 5-km range was designated as the circum-forest zone for container mosquitoes (except Ae. albopictus) in Japan, and an expanded concept, circum-boundary zone, is proposed. The widths of these zones primarily depend on the dispersal traits of mosquitoes. Whether the relation of Ae. albopictus and Ae. japonicus to forests we observed are common in the native and invasive ranges is discussed. The study of across-ecosystem dispersal is important for mosquito management under anthropogenically changing environments due to either deforestation or green restoration.

Stagnation Detection in Highly Multimodal Fitness Landscapes

Stagnation detection has been proposed as a mechanism for randomized search heuristics to escape from local optima by automatically increasing the size of the neighborhood to find the so-called gap size, i. e., the distance to the next improvement. Its usefulness has mostly been considered in simple multimodal landscapes with few local optima that could be crossed one after another. In multimodal landscapes with a more complex location of optima of similar gap size, stagnation detection suffers from the fact that the neighborhood size is frequently reset to 1 without using gap sizes that were promising in the past. In this paper, we investigate a new mechanism called radius memory which can be added to stagnation detection to control the search radius more carefully by giving preference to values that were successful in the past. We implement this idea in an algorithm called SD-RLSm\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{\ ext {m}}$$\\end{document} and show compared to previous variants of stagnation detection that it yields speed-ups for linear functions under uniform constraints and the minimum spanning tree problem. Moreover, its running time does not significantly deteriorate on unimodal functions and a generalization of the Jump benchmark. Finally, we present experimental results carried out to study SD-RLSm\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{\ ext {m}}$$\\end{document} and compare it with other algorithms.

Analyzing the relative importance of habitat quantity and quality for boosting pollinator populations in agricultural landscapes.

To increase pollinator populations, international policy targets minimum levels of seminatural habitat cover, but it is unknown whether improving the quality of existing habitats could bring similar benefits without the need of reducing cropland area. Using data we collected in 26 Italian agricultural landscapes during the entire flying season, we explored the relative importance of habitat quantity (seminatural habitat cover) and quality (flower availability) on pollinator densities in seminatural habitats. We obtained transect-based counts and estimated the effect of habitat quantity (proportion of seminatural habitat) and quality (flower cover and richness) on wild bee and hoverfly densities. We used the relationships revealed in the data to simulate pollinator population sizes in landscapes with varying habitat quantity and quality. Wild bee densities were only related to flower availability, whereas hoverfly densities were additionally related to seminatural habitat cover. We found that in complex agricultural landscapes (above 15% seminatural habitat cover), improving habitat quality increased pollinator populations more effectively than increasing habitat quantity. However, increasing habitat quantity was by far the most effective approach for boosting pollinator populations in simple landscapes.

The macro-eco-evolutionary interplay between dispersal, competition and landscape structure in generating biodiversity.

Theory links dispersal and diversity, predicting the highest diversity at intermediate dispersal levels. However, the modulation of this relationship by macro-eco-evolutionary mechanisms and competition within a landscape is still elusive. We examine the interplay between dispersal, competition and landscape structure in shaping biodiversity over 5 million years in a dynamic archipelago landscape. We model allopatric speciation, temperature niche, dispersal, competition, trait evolution and trade-offs between competitive and dispersal traits. Depending on dispersal abilities and their interaction with landscape structure, our archipelago exhibits two 'connectivity regimes', that foster speciation events among the same group of islands. Peaks of diversity (i.e. alpha, gamma and phylogenetic), occurred at intermediate dispersal; while competition shifted diversity peaks towards higher dispersal values for each connectivity regime. This shift demonstrates how competition can boost allopatric speciation events through the evolution of thermal specialists, ultimately limiting geographical ranges. Even in a simple landscape, multiple intermediate dispersal diversity relationships emerged, all shaped similarly and according to dispersal and competition strength. Our findings remain valid as dispersal- and competitive-related traits evolve and trade-off; potentially leaving identifiable biodiversity signatures, particularly when trade-offs are imposed. Overall, we scrutinize the convoluted relationships between dispersal, species interactions and landscape structure on macro-eco-evolutionary processes, with lasting imprints on biodiversity.This article is part of the theme issue 'Diversity-dependence of dispersal: interspecific interactions determine spatial dynamics'.

Influences of crop diversification on yield, resource use efficiency, and environmental footprint in farmland landscapes in intensive farming

Enhancing crop diversification in intensive fields has the potential to increase crop yield and reduce environmental footprint. However, these relationships at the landscape scale remained unclear in intensive farming. Addressing this gap, this paper aims to elucidate how crop yield, resources use efficiency (RUE), and environmental footprint (EF) vary with crop diversification levels in the North China Plain. Management practices, including crop pattern, field size, and agronomic inputs, were collected for 421 landscapes of 1 × 1 km subplots using Sentinel-2 and Landsat-8 images and survey. The results showed that, at the landscape scale, energy and fertilizer contributed over 53 %, and 37 % of the carbon footprint, respectively. N fertilizer constituted >98 % of the nitrogen footprint. P fertilizer accounted for over 80 %, while electricity comprised >13 % of the phosphorus footprint. Compared with simplified landscapes, diversified landscapes exhibited several significant features: 1) 56 % reduction of the area ratio of winter wheat-summer maize double crop pattern (WM), 2) a significant decrease in field size, 3) the decreased use of total NPK fertilizers at 32 %, 30 %, and 30 %, respectively, 4) the increased inputs of irrigation water, diesel, electricity, pesticide and labour at 21 %, 19 %, 21 %, 77 %, and 92 %, respectively. Although yield could be reduced at 33 % when transforming simplified landscapes into moderately diversified ones, they increased with the further promotion of crop diversification. Thus, the diversified landscapes could achieve a balance in yield, RUE, and EF to enhance sustainability, whereas simplified landscapes can similarly achieve a balance to benefit productivity. We emphasize the viable potential of diversified landscapes to enhance sustainable agricultural development by optimizing crop composition. This analysis offers pioneering evidence of landscape-scale agronomic and environmental performances of crop diversification.

Landscape simplification leads to loss of plant–pollinator interaction diversity and flower visitation frequency despite buffering by abundant generalist pollinators

AbstractAimGlobal change, especially landscape simplification, is a main driver of species loss that can alter ecological interaction networks, with potentially severe consequences to ecosystem functions. Therefore, understanding how landscape simplification affects the rate of loss of plant–pollinator interaction diversity (i.e., number of unique interactions) compared to species diversity alone, and the role of persisting abundant pollinators, is key to assess the consequences of landscape simplification on network stability and pollination services.LocationFrance, Germany, and Switzerland.MethodsWe analysed 24 landscape‐scale plant–pollinator networks from standardised transect walks along landscape simplification gradients in three countries. We compared the rates of species and interaction diversity loss along the landscape simplification gradient and then stepwise excluded the top 1%–20% most abundant pollinators from the data set to evaluate their effect on interaction diversity, network robustness to secondary loss of species, and flower visitation frequencies in simplified landscapes.ResultsInteraction diversity was not more vulnerable than species diversity to landscape simplification, with pollinator and interaction diversity showing similar rates of erosion with landscape simplification. We found that 20% of both species and interactions are lost with an increase of arable crop cover from 30% to 80% in a landscape. The decrease in interaction diversity was partially buffered by persistent abundant generalist pollinators in simplified landscapes, which were nested subsets of pollinator communities in complex landscapes, while plants showed a high turnover in interactions across landscapes. The top 5% most abundant pollinator species also contributed to network robustness against secondary species loss but could not prevent flowers from a loss of visits in simplified landscapes.Main ConclusionsAlthough persistent abundant pollinators buffered the decrease in interaction diversity in simplified landscapes and stabilised network robustness, flower visitation frequency was reduced, emphasising potentially severe consequences of further ongoing land‐use change for pollination services.

Higher crop rotational diversity in more simplified agricultural landscapes in Northeastern Germany

ContextBoth crop rotational diversity and landscape diversity are important for ensuring resilient agricultural production and supporting biodiversity and ecosystem services in agricultural landscapes. However, the relationship between crop rotational diversity and landscape diversity is largely understudied.ObjectivesWe aim to assess how crop rotational diversity is spatially organised in relation to soil, climate, and landscape diversity at a regional scale in Brandenburg, Germany.MethodsWe used crop rotational richness, Shannon’s diversity and evenness indices per field per decade (i.e., crop rotational diversity) as a proxy for agricultural diversity and land use and land cover types and habitat types as proxies for landscape diversity. Soil and climate characteristics and geographical positions were used to identify potential drivers of the diversity facets. All spatial information was aggregated at 10 × 10 km resolution, and statistical associations were explored with interpretable machine learning methods.ResultsCrop rotational diversity was associated negatively with landscape diversity metrics and positively with soil quality and the proportion of agricultural land use area, even after accounting for the other variables.ConclusionOur study indicates a spatial trade-off between crop and landscape diversity (competition for space), and crop rotations are more diverse in more simplified landscapes that are used for agriculture with good quality of soil conditions. The respective strategies and targets should be tailored to the corresponding local and regional conditions for maintaining or enhancing both crop and landscape diversity jointly to gain their synergistic positive impacts on agricultural production and ecosystem management.

Single-molecule epitranscriptomic analysis of full-length HIV-1 RNAs reveals functional roles of site-specific m6As

Although the significance of chemical modifications on RNA is acknowledged, the evolutionary benefits and specific roles in human immunodeficiency virus (HIV-1) replication remain elusive. Most studies have provided only population-averaged values of modifications for fragmented RNAs at low resolution and have relied on indirect analyses of phenotypic effects by perturbing host effectors. Here we analysed chemical modifications on HIV-1 RNAs at the full-length, single RNA level and nucleotide resolution using direct RNA sequencing methods. Our data reveal an unexpectedly simple HIV-1 modification landscape, highlighting three predominant N6-methyladenosine (m6A) modifications near the 3′ end. More densely installed in spliced viral messenger RNAs than in genomic RNAs, these m6As play a crucial role in maintaining normal levels of HIV-1 RNA splicing and translation. HIV-1 generates diverse RNA subspecies with distinct m6A ensembles, and maintaining multiple of these m6As on its RNAs provides additional stability and resilience to HIV-1 replication, suggesting an unexplored viral RNA-level evolutionary strategy.

Reducing pest pressure and insecticide use by increasing hedgerows in the landscape

Reducing pesticide use while maintaining agricultural production is a key challenge. Ecological theory predicts that landscape simplification is likely to increase insect pest outbreaks and limit their control by natural enemies, and this situation could boost insecticide use. Some studies have indeed detected that simpler landscapes were associated with higher insecticide use, but very few have demonstrated that this association is caused by landscape effects on pest abundance. Here, we analysed insecticide use and pest pressure in response to landscape simplification across 557 arable farms across France. Accounting for potentially confounding covariates, we found that lower cover of hedgerows in the landscape, but not semi natural areas, were associated with higher on-farm insecticide use. We also found that greater hedgerow coverage was associated with lower aphid pest pressure. Specifically, increasing the landscape-scale cover of hedgerows from 1 % to 3 % meant that insecticide use was halved. These findings suggest that restoring hedgerow cover at the landscape scale should be targeted in order to speed-up the ecological intensification of agriculture.

A Model for Spatially Explicit Landscape Configuration and Ecosystem Service Performance, ESMAX: Model Description and Explanation

It is critical that we move our understanding of the ecosystem services (ESs) produced by landscapes from the present abundance of analysis to a fundamental basis of design. This involves enhancing the ability to understand and model the interconnected, coevolving system of humans and the rest of nature, thus contributing to the design of sustainable landscapes. In this paper, we hypothesise that the spatial configuration of landscape components (the size and arrangement of tree clumps, paddocks, crops, water features, etc.) impacts the production of regulating ESs, which in turn have a leveraging effect on provisioning and cultural ESs. Drawing on the precepts of Ecological Field Theory, we present the development and implications of a conceptual Geographic Information System (GIS)-based model, ESMAX, that utilises the idiosyncratic distance-decay characteristics of regulating ESs. These ‘ES fields’ are visualised as radiating into the landscape from their source components, addressing a gap in biophysical reality that has been identified as a shortcoming of existing ES modelling based on landcover proxies. Hypothetical landscape arrangements of simplified landscape components are tested with ESMAX across three regulating ESs: cooling effect, nitrogen retention, and habitat provision. The model calculates the overall ES performance of each landscape arrangement by tabulating the ES fields produced and, critically, the nonlinear response where fields overlap. The results indicate a primary sensitivity to the size of components and a secondary sensitivity to the arrangement of components. Consequently, ESMAX can be used to design landscape configurations that (1) maximise the production of specific regulating ESs and (2) improve the utilisation of natural ES-producing resources.

Pesticide use negatively affects bumble bees across European landscapes

Sustainable agriculture requires balancing crop yields with the effects of pesticides on non-target organisms, such as bees and other crop pollinators. Field studies demonstrated that agricultural use of neonicotinoid insecticides can negatively affect wild bee species1,2, leading to restrictions on these compounds3. However, besides neonicotinoids, field-based evidence of the effects of landscape pesticide exposure on wild bees is lacking. Bees encounter many pesticides in agricultural landscapes4–9 and the effects of this landscape exposure on colony growth and development of any bee species remains unknown. Here we show that the many pesticides found in bumble bee-collected pollen are associated with reduced colony performance during crop bloom, especially in simplified landscapes with intensive agricultural practices. Our results from 316 Bombus terrestris colonies at 106 agricultural sites across eight European countries confirm that the regulatory system fails to sufficiently prevent pesticide-related impacts on non-target organisms, even for a eusocial pollinator species in which colony size may buffer against such impacts10,11. These findings support the need for postapproval monitoring of both pesticide exposure and effects to confirm that the regulatory process is sufficiently protective in limiting the collateral environmental damage of agricultural pesticide use.

Hedgerows can increase predation rates in wheat fields in homogeneous agricultural landscapes

In agricultural landscapes, semi-natural habitats can support populations of beneficial species, such as natural enemies. Using artificial caterpillars made of plasticine, we compared arthropod and vertebrate predation rates in wheat fields adjacent to hedgerows or spontaneous grass margins in two contrasting agricultural landscapes. Overall, 25.3% of the caterpillars were attacked after 24 h, mainly by arthropods (67.1%). Predation rates in the heterogeneous and homogeneous landscapes were similar (mean ± SE; 24.9% ± 3.0% vs 25.7% ± 3.6%, n = 10 per landscape). However, we found a significant interaction between the margin and landscape type. Total (arthropods + vertebrates) predation rates were significantly higher in wheat fields next to hedgerows than in conventional wheat fields with grass margins in the homogeneous landscape (33.7% ± 4.5% vs 17.7% ± 2.5%, n = 5 per margin type and landscape), while no difference between predation rates in the two margin types was detected in the heterogeneous landscape. Total and vertebrate predation rates were positively affected by plant species richness, which suggest that one of the mechanisms through which hedgerows can support higher predator activity than spontaneous grass margins, particularly in homogeneous agricultural landscapes, is by providing higher plant diversity. Our results suggest that in simple landscapes, hedgerows may act as habitat islands of high conservation value for biodiversity, having a disproportionate value compared to hedgerows in landscapes that include forest fragments and other semi-natural habitats.

Ecosystem stability of temperate grasslands in response to variability of hydrological conditions

AbstractThe relationship between biodiversity and the stability of ecosystem functioning over time has been widely studied. The current global context has refloated this topic for biodiversity's role in buffering the effects of different disturbances. In general, the results of these studies show that ecosystem functioning is more stable over time in more diverse systems. However, these results are derived from empirical research on small‐scale studies, where species and disturbances conditions are manipulated. In this work, we used climate and floristic information data obtained from surveys over an extended period on Flooding Pampa grasslands (Argentina) with a remotely sensed indicator of the stability of net primary productivity at a regional scale over a broad temporal range to evaluate the relationship between species diversity and the stability of ecosystem functioning under different water conditions. We found a close correlation between Normalized Difference Vegetation Index responses of natural grasslands and climate variability in the study area. Besides, grasslands with higher species richness and diversity showed greater stability in ecosystem functioning at different water conditions. The results obtained could be relevant in natural resource management for the close relationship between diversity–stability in a local and regional productive context characterized by a simplified landscape of space and time.

The Homecoming of Ștefan Sadovnicov

Ștefan Sadovnicov is the artist who approaches several genres of painting. His creative activity is based on the connection of the three fields of arts: painting, music and literature. He writes poems, evokes the old times, paints. That is why the city of his childhood and youth – Bălți – appears to him represented as a universe rich in colors, shapes, sounds, etc. In all the works with this motif we feel the artist’s affection for the city of his soul. Ștefan Sadovnicov is one of the few artists of great sensitivity, depth and intelligence. The series of paintings with the title „the city that no longer exists...”, executed in the 70s–80s, are not just simple landscapes with buildings specific to the time, they retain deep meanings. The main reasons are longing, going back in time, nostalgic memories, etc. the visual artist did not simply paint the urban landscape, but selected the histories of the streets and buildings of Bălți, looked for old pictures and asked the residents. He approached the subject philosophically, drawing a parallel between the city and people who have souls.

Habitat quality, not patch isolation, drives distribution and abundance of two light-demanding butterflies in fragmented coppice landscapes

Coppice forests are socio-ecological systems especially rich in biodiversity. They have been transformed into high forest and abandoned across large areas of Europe over the past 200 years. Coppice loss is likely an important driver of insect declines. It is currently unclear whether habitat quality or decreasing connectivity of the remaining fragments is more important for the survival of insect populations. We related the abundance of two coppice-associated butterflies of conservation concern, Satyrium ilicis and Melitaea athalia, to indicators of habitat quality and habitat connectivity. We estimated butterfly densities using Distance Sampling along a successional gradient (time since last cut: 1–9 years; N = 130 plots) across one of the largest remaining simple oak-birch coppice landscapes in Central Europe. Both species reached abundance peaks within four to six years after the last cut, declining rapidly in abundance with subsequent succession. We found no evidence that coupe size, coppice availability and patch (= coupe) connectivity were related to the density of the species. Besides stand age, the cover of larval foodplants explained predicted butterfly densities well. Only Satyrium ilicis benefitted from high Red Deer densities.Implications for insect conservation: Our results suggest that habitat quality and sufficient availability of coppice of suitable age matters more than coupe size and fragmentation within a traditional managed coppice landscape. Coppice restoration aiming at the study species should ensure a shifting mosaic of successional habitat to provide a large availability of resprouting oak stools and bilberry vegetation that holds dense Melampyrum pratense stands.

Floral resources,energetic value and pesticide residues in provisions collected by Osmia bicornis along a gradient of oilseed rape coverage

Pollinators in agricultural landscapes are facing global decline and the main pressures include food scarcity and pesticide usage. Intensive agricultural landscapes may provide important food resources for wild pollinators via mass flowering crops. However, these are monofloral, short-term, and may contain pesticide residues. We explored how the landscape composition with a different proportion of oilseed rape (6–65%) around Osmia bicornis nests affects floral diversity, contamination with pesticides, and energetic value of provisions collected by this species of wild bees as food for their offspring. Altogether, the bees collected pollen from 28 plant taxa (6–15 per nest) and provisions were dominated by Brassica napus (6.0–54.2%, median 44.4%, 12 nests), Quercus sp. (1.2–19.4%, median 5.2%, 12 nests), Ranunculus sp. (0.4–42.7%, median 4.7%, 12 nests), Poaceae (1.2–59.9%, median 5.8%, 11 nests) and Acer sp. (0.6–42%, median 18.0%, 8 nests). Residues of 12 pesticides were found in provisions, with acetamiprid, azoxystrobin, boscalid, and dimethoate being the most frequently detected at concentrations up to 1.2, 198.4, 16.9 and 17.8 ng/g (median 0.3, 10.6, 11.3, 4.4 ng/g), respectively. Floral diversity and energetic value of provisions, but not the Pesticide Risk Index depended on landscape structure. Moreover, pollen diversity decreased, and energetic value increased with landscape diversity. Thus, even a structurally simple landscape may provide diverse food for O. bicornis if the nest is located close to a single but resource-diverse patch. Both B. napus and non-crop pollen were correlated with pesticide concentrations.

How landscape characteristics in a heterogeneous oil palm plantation mitigate pest abundance: A case study from Mapiripán, Colombia

The oil palm sector is widely known for its strong impact on biodiversity and human well-being. The United Nations Sustainable Development Goals (SDG) framework calls for a sustainable biodiversity management approach to oil palm plantations and thereby balancing palm oil production and biodiversity conservation. Heterogeneous agricultural landscapes, comprising different vegetation types in a complex spatial pattern, provide habitat to a variety of species and support high biodiversity. Biodiversity can thus offer pest control ecosystem services to agricultural systems. However, so far it remains unclear whether landscape structure and diversity foster or mitigate pest occurrences in plantations. Our case study is the oil palm plantation of Mapiripán in Colombia, which integrates local ecosystems such as secondary forests, relict old-grown forests, riparian forests, and water body remnants in between and around the palm stands of the plantation. With this nature-improved design, we ££pose two main questions: which landscape structural properties characterize the landscape of the oil palm plantation?, and how do specific landscape structural properties foster or mitigate the presence of two main oil palm pests (the butterfly larvae split-banded owlet (Opsiphanes cassina) and the red weevil (Rhynchophorus palmarum))? We first characterize the plantation landscape with a multivariate cluster analysis which led us to identify up to nine different landscape structural types for the Macondo plantation. A mosaic of different landscape types ranging from homogeneous and simple landscapes to heterogeneous, diversified, and connected landscape types. Second, we performed an NMDS ordination to show similarities among the landscape structural types, land cover, and pest occurrence. Our results show that the integration of local ecosystems such as forests and water bodies improves landscape connectivity and suppresses the abundance of the two main oil palm pests.

Agricultural land-use and landscape composition: Response of wild bee species in relation to their characteristic traits

In the past centuries, farmland has undergone a fundamental transformation through changed farming practices, such as the use of agrochemicals and advanced machine processing. Particularly since the 1970s, agriculturally driven land-use change has caused destruction of natural and semi-natural habitats, and as a consequence, severe loss of biodiversity. Hence, identifying landscape patterns and habitats that enhance species richness, and detecting species and traits that are most vulnerable to intensive land-use are prerequisites for conservation. To evaluate the effects of agricultural land-use and landscape composition on wild bees, we investigated 340 cross-transects in 34 test areas in the main agricultural regions of Austria within the framework of the biodiversity monitoring program BINATS. Using multivariate models (GLM, DCA), wild bees and potential explanatory parameters (e.g. Shannon landscape diversity index, plant diversity, flower cover) were documented, and their interrelationships analyzed. We found strong negative effects of increased agricultural land cover on species richness, abundance and functional richness. Species richness was positively correlated with an increasing area of semi-natural elements (e.g. extensive grassland, hedgerows, fallows) and the number of different habitat types, while wild bee abundance was best explained by the presence of semi-natural habitats and flower cover. Colletidae were significantly associated with the area of semi-natural elements, and were especially sensitive to agricultural intensification. Many species from communities that are present in complex landscapes disappeared in intensively managed farmland, and the majority of species decreased in response to simplified landscapes. A few species, however, even benefited. Our results emphasize the importance of diverse semi-natural elements and high regional flower cover within farmland for maintaining and enhancing species richness and abundance, and for promoting a positive spillover effect of pollinators to the surrounding agricultural landscape. Especially members of the family Colletidae, with a high proportion of specialized species, will benefit from diverse semi-natural habitat types. Given the unique importance of wild bees as pollinators of wildflowers and crops, it is crucial to improve and expand agri-environmental schemes to combat ongoing biodiversity loss in farmland.