Homogeneous Landscape Research Articles

Effects of ungulate density and sociality on landscape heterogeneity: a mechanistic modeling approach

Animals can be important vectors of nutrient transfer within and across landscapes, with important implications for ecosystem productivity and composition. While it is presumed large ungulates are agents of nutrient dispersal via movement and activity, research analyzing their net effects on landscapes remains scarce. We present an individual‐based model that investigates how caribou affect the distribution of nutrients on a landscape through consumption only, as well through the cumulative effects of consumption and nutrient deposition (i.e. fecal waste and carcass deposition). We explored these dynamics in simulations that altered the context of environments, either initially containing heterogeneous or homogeneous nutrient distributions, animal densities and sociality of caribou behavior. In the consumption‐only simulations, caribou density and sociality created different patterns of heterogeneity at both the landscape and local scale depending on the initial landscape conditions. In these simulations, caribou populations crashed at high densities because the lack of animal deposition resulted in low resources across the landscape. This was not the case when considering the cumulative effects of consumption and deposition, indicating the return of nutrients from animals may be important for population stability. Additionally, in simulations considering the cumulative effects of caribou, increasing caribou density increased landscape heterogeneity irrespective of the initial condition (i.e. heterogeneous and homogeneous landscapes), and maintained or increased local heterogeneity in heterogeneous and homogenous landscape, respectively. Importantly, in all simulations the net impact of caribou at the individual patch level was extremely variable, suggesting that animal inputs are highly varied throughout the landscape. Our results indicate the movement of large ungulates such as caribou can increase the heterogeneity of available nutrients within a landscape and provide an important feedback for population stability. Thus, the loss of large ungulates from natural ecosystems via anthropogenic activity is likely to result in less heterogeneous natural landscapes.

RETRACTED ARTICLE: Planning of agricultural ecological scenery based on the concept of traditional rural culture

This article has been retracted from publication in the Taylor & Francis journal, Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. Following publication, concerns were raised by multiple third-parties around the content of the special issue and the decision-making process. Following an investigation by the Taylor & Francis Publishing Ethics & Integrity team in full cooperation with the Editor-in-Chief, it was confirmed that this article included in Special Issue titled “ Envisage Computer Modelling and Statistics for Agriculture”, guest edited by Gunasekaran Manogaran was not peer-reviewed appropriately, in line with the Journal's peer review standards and policy. As the stringency of the peer review process is core to the integrity of the publication process, the Editor and Publisher have decided to retract all of the articles within the above-named Special Issue. The journal has not confirmed if the authors were aware of this compromised peer review process. The journal is committed to correcting the scientific record and will fully cooperate with any institutional investigations into this matter. The authors have been informed of this decision. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines.

Land cover change detection in the Aralkum with multi-source satellite datasets

ABSTRACT The Aral Sea, once the fourth largest freshwater lake on Earth, has lost circa 90% of its original water surface in 1960. Maps of different land cover categories provide a suitable baseline to plan and implement effective measures to combat ongoing desertification, such as reforestation of dried out Aral Sea soils. In this study, we used satellite-based remote sensing data and applied a machine learning method (Random Forest) to map land cover in the Aralkum in 2020. We tested different satellite data from optical (Landsat-8, Sentinel-2) and Radar instruments (Sentinel-1) and trained a random forest model for classifying different combinations of these data sets into ten distinct land cover classes. We further calculated per-pixel uncertainty based on posterior classification probability scores. An accuracy assessment, based on in-situ data, revealed that the average overall accuracy of land cover maps was 86.8%. Fusing optical and radar instruments achieved the highest overall accuracy (88.8%, with lower/higher 95% confidence interval values of 87.6%/89.9%, and a Kappa value of 0.865. Classification uncertainty was lower in more homogeneous landscapes (i.e. large expanses of a single land cover class like water or shrubland). Only around 9% of the study area was still water in 2020, while 32% was covered by saline soils with high erosion risk. Several potential applications of this land cover map in the Aralkum exist – spanning many areas of environmental impact assessment, policy, and planning and management or afforestation. This methodological framework can similarly provide a useful template for more broadly assessing large-scale, land dynamics at high-resolution in the entire Aralkum and surrounding areas.

Farmland biodiversity: wildflower-sown islands within arable fields and grassy field margins both promote spider diversity

Agricultural intensification and the concomitant landscape homogenization is leading to a worldwide decline in farmland biodiversity. Non-crop habitats in agroecosystems may counteract the loss of arthropods such as spiders and thus contribute to sustainable agriculture. However, the effectiveness of field margins and set-aside wildflower-sown patches in maintaining spider diversity is not well understood. Here, we investigated the effects of three different non-crop habitats, namely field margins, set-aside wildflower-sown patches under power poles (‘power pole islands’), and grassland fallows on spider diversity as compared to wheat fields in an agricultural landscape in western Germany. Using pitfall trapping and suction sampling, we show that species richness and overall conservation value were higher in non-crop habitats than in wheat fields. Interestingly, field margins and power pole islands differed from long-term grassland fallows only in conservation value, which was significantly higher in grassland fallows. Species assemblages differed considerably between grassland fallows, field margins and power pole islands, and wheat fields, documenting the added value of using different conservation strategies.Implications for insect conservationSmall-scale non-crop habitats adjacent to wheat fields were surprisingly effective in promoting spider diversity in an agricultural landscape, with field margins and power pole islands being equally effective. To maximize overall diversity in agricultural landscapes, we propose a combination of larger long-term fallows and smaller non-crop habitats such as field margins or set-aside wildflower-sown patches.

Landscape Changes of Rural Protected Landscape Areas in Czechia: From Arable Land to Permanent Grassland – From Old to New Unification?

Abstract The Czech rural landscape is a subject of research because it is affected by both intensification and extensification of land cover. This landscape was influenced in recent decades by political and socio-economic changes; we studied how these changes were reflected in the land cover development in protected areas. We selected ten Protected landscape areas (PLAs) with a significant share of open agricultural landscape and focused on land cover changes from the 1950s till the present with four milestones (1950s, 1990, 2004-2006, 2016-2019). Based on vectorised land cover data, analyses of land cover changes, land cover flows and landscape structure were performed. More than one third of the studied area had changed. Forests dominated and enlarged its extent (from 39 % to 47 %); land cover flow (LCF) from arable land to permanent grassland was the largest process during study period (17% of study area) and it expanded after 1990. Other major LCF is forest spreading on permanent grassland (5 %) and arable land (3 %). Trends of landscape metrics describing landscape structure are ambiguous and differ between PLAs. In total, Shannon’s diversity index (SDI), Shannon’s evenness index (SEI), and Mean Patch Size (MPS) increased and Number of Patches (NumP) decreased. SDI and SEI show improvement through time; however increasing anthropogenic areas are considered as factor contributing to this positive trend, despite the negative role of these categories in ecological stability. MPS and NumP show ongoing homogenization and unification of the landscape; however it differs between PLAs, with some having more favourable conditions and trends towards higher landscape heterogeneity. To conclude, homogenous landscape structure remains present in Czech rural PLAs; however, there has been a huge shift to more extensive agricultural land cover, which is similar to some European protected areas.

Effects of wildflower strips, landscape structure and agricultural practices on wild bee assemblages – A matter of data resolution and spatial scale?

Agricultural systems in Central Europe were redesigned during the last century to attain maximum yields. The results often lead to homogeneous landscapes with only few structures of ecological value and have concurrently exacerbated habitat fragmentation. Perennial wildflower strips have become a significant agri-environmental measure (AEM) to counteract the ecological consequences for wild bees and other pollinators in agricultural landscapes. The effectiveness of AEMs depends on the landscape context, but information about geodata sources and spatial scales relevant for the analysis of landscape effects on wild bees is lacking. This study uses data from various sources on land cover and agricultural practices to assess their applicability in an evaluation of perennial wildflower strips as AEM for wild bees in Saxony-Anhalt, Germany. We investigated the relationships of wild bee species diversity and abundance to the landscape context at spatial scales from 200 m to 10 km considering several factors: land cover/land use, protected areas, crop types, agri-environment schemes/greening, intensity of agriculture, and intensity of grassland farming. In general, our results revealed that landscape effects were more relevant for solitary than social wild bees on flower strips, pointing to a higher limitation of solitary wild bees in nesting resources as compared to social wild bees. Numbers of wild bee species and individuals benefitted from bare soil and ecological focus areas in the surroundings up to 3 km distance, whereas the share of Red List solitary bee species was positively influenced by a variety of factors (e.g., wood structures and grasslands) especially at large scales up to 10 km. The comparison of models based on different land cover data sources showed that the lack of geodata resolution can mask landscape effects on wild bees. Altogether, our results suggest a high potential of data from the Basic Digital Landscape Model (DLM), together with the Integrated Administration and Control System (IACS), to indicate effects of landscape structures and agricultural practices on the species composition and distribution of wild bee assemblages in Germany.

Homogenization and locality of landscape characteristics in the waterfront space based on geotagged photographs

AbstractThe urban landscape reveals the relationship between the natural evolution process and artificial intervention force in the watershed system and also represents the most direct reflection of man–land relationships in watersheds. However, the homogeneity of modern urban functions affects the expression of cultural atmospheres. As a result, quantitative and qualitative analyses of the landscape homogenization level are of great significance for considering local culture in landscape planning according to locality conditions. In this study, open geotagged photographs were assessed to determine the landscape changes and differences in the Yangtze River Basin and the spatial characteristics of locality elements in order to identify the relationship between landscape locality and urbanization. The results indicate that the landscape element level changes gradually downstream of the Yangtze River and with increasing distance from the river bank. The closer the city to the lower reaches of the Yangtze River, the less dominant the main landscape element of the city. Several landscape elements were significantly agglomerated in space, and this agglomeration distribution was attributed to the degree of urbanization.

Environmental heterogeneity and water availability shape the structure of phyllostomid bat assemblages (Mammalia: Chiroptera) in the northeastern Amazon forest

The relationship between environmental heterogeneity and species diversity has been one of the most studied patterns in ecology. However, some taxa and regions worldwide still lack studies to verify this relationship. Phyllostomidae is the most ecologically diverse family of mammals worldwide, encompassing a great proportion of the species of mammals and bats across the Amazon forest. Even though the Amazon seems to be a homogeneous landscape with an unlimited supply of water, it presents a high variation in vegetation types and proximity to large bodies of water. In our study, we have analyzed the relationship between environmental heterogeneity and proximity to large bodies of water in the structure of phyllostomid assemblages (Chao-estimated species richness and capture rates). We have found that an increase in landscape heterogeneity associated with large bodies of water and representative flooded forest increase species richness. In addition, more heterogeneous landscapes in the presence of water have presented a higher abundance of bats. Our findings might be related with the small niche widths of phyllostomids, which could have promoted specialization in some landscape features, while the presence of water could have promoted an increase in food availability (insects and fruits), leading to an increase in phyllostomid richness and abundance. This is important information for planning where to place protected areas in the northeastern portion of the Amazon, while taking into account the consequences of drought and deforestation close to water bodies on the local phyllostomid fauna, and the maintenance of the ecosystem services provided by a higher bat diversity.

Cold and heterogeneous T cell repertoire is associated with copy number aberrations and loss of immune genes in small-cell lung cancer

Small-cell lung cancer (SCLC) is speculated to harbor complex genomic intratumor heterogeneity (ITH) associated with high recurrence rate and suboptimal response to immunotherapy. Here, using multi-region whole exome/T cell receptor (TCR) sequencing as well as immunohistochemistry, we reveal a rather homogeneous mutational landscape but extremely cold and heterogeneous TCR repertoire in limited-stage SCLC tumors (LS-SCLCs). Compared to localized non-small cell lung cancers, LS-SCLCs have similar predicted neoantigen burden and genomic ITH, but significantly colder and more heterogeneous TCR repertoire associated with higher chromosomal copy number aberration (CNA) burden. Furthermore, copy number loss of IFN-γ pathway genes is frequently observed and positively correlates with CNA burden. Higher mutational burden, higher T cell infiltration and positive PD-L1 expression are associated with longer overall survival (OS), while higher CNA burden is associated with shorter OS in patients with LS-SCLC.

Grid resolution dependency of land surface heterogeneity effects on boundary‐layer structure

AbstractLand surface heterogeneity exerts a strong control on atmospheric boundary‐layer (ABL) evolution by spatially varying the distribution and partitioning of surface energy fluxes and triggering secondary circulations. The representation of this physical process in numerical weather prediction (NWP) models is especially affected in the terra incognita as the model grid resolution approaches the length‐scale of the largest eddies in the boundary layer. We explore these effects for a mesoscale strip‐like land surface inhomogeneity in land cover, soil moisture or a superposition of both embedded in an elsewhere homogeneous landscape. The study is conducted with the numerical weather prediction model ICON (ICOsahedral Nonhydrostatic), using the default operational level 2.5 Mellor–Yamada turbulence closure (MY) and a large‐eddy simulation (LES) configuration as a benchmark. While simulations with the default ABL scheme approach the LES reference when refining the spatial grid towards finer resolution, the model generates artificial circulations leading to ABL height oscillations when the horizontal grid resolution approaches the ABL height . The effect of these model‐induced circulations on the state of the boundary layer is even present with weak thermal heterogeneity under low background wind speed ( but diminishes with increasing background wind speed. The tuning of the asymptotic turbulent mixing length‐scale in the operational ABL scheme helps in reducing the amplitude of the oscillations, thereby reducing the artificially induced circulations due to thermal heterogeneity which might act as unintentional trigger for clouds and precipitation. Based on the tuned synthetic model data from sensitivity runs, we propose a new parametrization for a 2‐D as a function of , and , which is otherwise held as a constant in the ABL scheme.

Rapid simulations of hyperspectral near-field images of three-dimensional heterogeneous surfaces.

The scattering-type scanning near-field optical microscope (s-SNOM) has emerged as a powerful tool for resolving nanoscale inhomogeneities in laterally heterogeneous samples. However, most analytical models used to predict the scattering near-field signals are assuming homogenous landscapes (bulk materials), resulting in inconsistencies when applied to samples with more complex configurations. In this work, we combine the point-dipole model (PDM) to the finite-element method (FEM) to account for the lateral and vertical heterogeneities while keeping the computation time manageable. Full images, spectra, or hyperspectral line profiles can be simulated by calculating the self-consistent dipole radiation demodulated at higher harmonics of the tip oscillation, mimicking real experimental procedures. Using this formalism, we clarify several important yet puzzling experimental observations in near-field images on samples with rich typography and complex material compositions, heterostructures of two-dimensional material flakes, and plasmonic antennas. The developed method serves as a basis for future investigations of nano-systems with nontrivial topography.

Varying Partitioning of Surface Turbulent Fluxes Regulates Temperature‐Humidity Dissimilarity in the Convective Atmospheric Boundary Layer

AbstractExperimental evidence shows that temperature‐humidity () similarity in the atmospheric surface layer (ASL) is reduced as Bowen ratio () increases over land. However, underlying physical mechanisms remain not well understood. With large‐eddy simulations, dissimilarity is investigated in the steady‐state, convective boundary layer (CBL) over homogeneous landscape with varying . As increases from 0.4 to 2.0, the entrainment ratio for slightly decreases but that for q largely increases. As a result, local production of humidity variance is substantially enhanced in the upper CBL and transported to the lower CBL by vigorous large eddies, contributing significantly to nonlocal fraction. However, the increased temperature variance in the ASL associated with strong heat flux is larger than that transported from the upper CBL. Such asymmetry in vertical diffusion induced by varying partitioning of surface fluxes strongly regulates dissimilarity even under perfect conditions valid for Monin‐Obukhov similarity theory.

Land Use Modeling Predicts Divergent Patterns of Change Between Upper and Lower Elevations in a Subalpine Watershed of the Alps

The synergic influence of land use and climate change on future forest dynamics is hard to disentangle, especially in human-dominated forest ecosystems. Forest gain in mountain ecosystems often creates different spatial–temporal patterns between upper and lower elevation belts. We analyzed land cover dynamics over the past 50 years and predicted Business as Usual future changes on an inner subalpine watershed by using land cover maps, derived from five aerial images, and several topographic, ecological, and anthropogenic predictors. We analyzed historical landscape patterns through transition matrices and landscape metrics and predicted future forest ecosystem change by integrating multi-layer perceptron and Markov chain models for short-term (2050) and long-term (2100) timespans. Below the maximum timberline elevation of the year 1965, the dominant forest dynamic was a gap-filling process through secondary succession at the expense of open areas leading to an increase of landscape homogeneity. At upper elevations, the main observed dynamic was the colonization of unvegetated soil through primary succession and timberline upward shift, with an increasing speed over the last years. Future predictions suggest a saturation of open areas in the lower part of the watershed and stronger forest gain at upper elevations. Our research suggests an increasing role of climate change over the last years and on future forest dynamics at a landscape scale.

Channel‐reach morphology and landscape properties are linked across a large heterogeneous region

AbstractGiven the complex array of processes influencing river networks, conceptual frameworks of rivers are critical to our understanding of channel processes and response potential, as well as restoration efforts. Yet despite their wide usage, many classifications are based on limited observations over homogenous landscapes, raising questions about their general applicability and quantitative thresholds. Leveraging a large, transect‐based morphological field dataset across California, USA, we use data‐driven methods to evaluate multivariate patterns in channel morphology and linkages with landscape properties considering a diversity of physio‐climatic settings. Emergent patterns highlight the variability in channel form observed across an extensive dataset over heterogeneous but spatially linked watersheds. In general, identified dominant channel attributes and landscape properties align with established channel types defined through expert judgement, but key differences also emerge. Similar to past studies, bed sediment composition and sub‐reach depth variability were discriminating channel attributes. The dominance of landscape properties associated with sediment supply or transport capacity suggests that morphological diversity largely reflects these differences as posited by prior classifications. Results also show some channel forms to be largely independent of valley confinement, with several channel bedforms and dominant grain sizes occurring across valley settings. This data analysis study demonstrates the utility of considering channel reaches and landscapes as multi‐dimensional features to elucidate and test established geomorphic understanding over large field datasets.

Taxon- and functional group-specific responses of ground beetles and spiders to landscape complexity and management intensity in apple orchards of the North China Plain

Agricultural intensification has caused severe declines in ground-dwelling arthropods and associated ecosystem services. The conservation and re-establishment of semi-natural habitats in agricultural landscapes represent widely accepted measures to counter these declines. The effectiveness of these measures nonetheless varies between target taxa and their functional traits, while also being affected by local management. Here, we studied how species richness and abundance of different functional groups of carabid beetles and spiders in apple orchards were affected by landscape complexity (% semi-natural habitat) and local management intensity (mowing and soil total nitrogen (STN) content). Both abundance and species richness of non-carnivorous carabids and carabids overall were negatively affected by STN, while the abundance of carnivorous carabids and carabids overall was affected by interactive effects of mowing and landscape complexity, showing a positive response to mowing where semi-natural habitats are scarce, but negative responses in landscapes with a higher proportion of semi-natural habitats. The abundance of ground-hunting spiders and spiders overall was generally positively related to % semi-natural habitats, while the abundance of web-building spiders and the species richness of ground-hunting spiders showed a positive correlation with STN at landscapes with a low or medium abundance of semi-natural habitats, but a negative correlation where semi-natural habitats were more abundant. Non-carnivorous carabid diversity benefitted from low nitrogen application, while carnivorous carabid abundance benefitted from mowing intensity especially in simple and structurally homogenous agricultural landscapes. Both web-building and ground-hunting spiders positively responded to low nitrogen applications and intermediate landscape complexity. Overall, a low local management intensity promoted carabid beetles, while spiders were favored by increasing landscape complexity. We conclude that taxon- and functional group-specific, multi-scale conservation strategies are therefore required to conserve invertebrate predators in apple orchards.

Preserving wintering frugivorous birds in agro‐ecosystems under land use change: Lessons from intensive and super‐intensive olive orchards

Abstract Fleshy fruit production is becoming more intensive worldwide, but how this affects frugivorous birds is poorly known. In the Mediterranean region, intensive and super‐intensive olive orchards are fast expanding, potentially affecting millions of wintering songbirds. Here, we test the idea that intensification may benefit frugivorous birds, at least locally, due to increased fruit availability, while negatively affecting the wider wintering bird community due to intensive management, structural simplification and landscape homogenisation. We estimated olive abundance and surveyed birds in early, mid‐ and late winter, at traditional, intensive and super‐intensive orchards in southern Portugal. We used Hierarchical Modelling of Species Communities to relate species richness, prevalence and abundance to management intensity, winter period, olive availability and landscape context, and evaluated the role of frugivory in modulating observed responses. Olive availability was much higher throughout the winter in more intensive than in traditional orchards, both in trees and on the ground. Frugivorous bird abundance was higher in more intensive orchards, and the most abundant frugivorous species (blackcap, song thrush, robin) were positively affected by olive availability and/or increasing landscape cover by olive orchards, while intensification level had relatively minor effects after accounting for other variables. Non‐frugivorous richness and abundance were higher in traditional orchards, and many non‐frugivorous species had lower prevalence in more intensive orchards or were negatively affected by landscapes dominated by olive cultivation. Synthesis and applications. While negatively affecting the wider bird community, our results suggest that olive farming intensification can contribute to sustaining large numbers of frugivorous birds in the Mediterranean region. As frugivorous birds are not seen as damaging by olive farmers, there is an opportunity to promote their conservation in intensive and super‐intensive orchards, which requires management to increase habitat heterogeneity, and to reduce risks such as mortality associated with mechanical harvest and contamination with pesticide residues. Overall, we recommend that efforts to manage farmland biodiversity should consider the impacts and conservation opportunities of fruit crop intensification.

Landscape composition and life‐history traits influence bat movement and space use: Analysis of 30 years of published telemetry data

AbstractAimAnimal movement determines home range patterns, which in turn affect individual fitness, population dynamics and ecosystem functioning. Using temperate bats, a group of particular conservation concern, we investigated how morphological traits, habitat specialization and environmental variables affect home range sizes and daily foraging movements, using a compilation of 30 years of published bat telemetry data.LocationNorthern America and Europe.Time period1988–2016.Major taxa studiedBats.MethodsWe compiled data on home range size and mean daily distance between roosts and foraging areas at both colony and individual levels from 166 studies of 3,129 radiotracked individuals of 49 bat species. We calculated multi‐scale habitat composition and configuration in the surrounding landscapes of the 165 studied roosts. Using mixed models, we examined the effects of habitat availability and spatial arrangement on bat movements, while accounting for body mass, aspect ratio, wing loading and habitat specialization.ResultsWe found a significant effect of landscape composition on home range size and mean daily distance at both colony and individual levels. On average, home ranges were up to 42% smaller in the most habitat‐diversified landscapes while mean daily distances were up to 30% shorter in the most forested landscapes. Bat home range size significantly increased with body mass, wing aspect ratio and wing loading, and decreased with habitat specialization.Main conclusionsPromoting bat movements through the landscape surrounding roosts at large spatial scales is crucial for bat conservation. Forest loss and overall landscape homogenization lead temperate bats to fly further to meet their ecological requirements, by increasing home range sizes and daily foraging distances. Both processes might be more detrimental for smaller, habitat‐specialized bats, less able to travel increasingly longer distances to meet their diverse needs.

Forest expansion in mountain protected areas: Trends and consequences for the landscape

Mountain regions in Western Europe have gone through a massive rural–urban migration and the collapse of their traditional socioeconomic system. As a result, forest has occupied many old pastures and croplands. In protected areas – such as National Parks – changes in the landscape can affect biodiversity and other services, including the values that motivated their declaration. Any policy decision in these areas requires quantifying the extent and impact of land-cover changes and their consequences on landscape structure and functioning. In this study we analyze the patterns of change in forest cover during six decades in three mountain National Parks in Spain. Our aim is to quantify those patterns, their effects on the landscape, and discuss the potential consequences for the main natural values and services. We assessed changes in forest cover through reclassification of aerial ortophotographs taken in 1956–57 (past images) and 2016–17 (recent images). The three Parks show a relatively low change in total forest area (+5–10%), and a much larger increase in dense forest (+20–30%), with an important effect of land-use legacies, and similar patterns of landscape homogenization. There were fewer but larger forest patches in 2016 than in 1956, and most of the gain in dense forest occurred in core areas (+20%), while transition areas such as edges, bridges or loops decreased between 30 and 55%. Given their potential consequences on biodiversity and other services, these patterns of land-cover change and landscape configuration should be explicitly considered when designing the sustainable management of abandoned landscapes in protected areas.

Reduced diversity of farmland birds in homogenized agricultural landscape: A cross-border comparison over the former Iron Curtain

Agricultural intensification led to a transformation of structurally complex agricultural landscapes that resulted in a subsequent loss of landscape heterogeneity. Landscape homogenization is considered a crucial process which influences farmland biodiversity; however, separating the effects of homogenization from other environmental gradients is difficult and rarely tested. This study aimed to compare farmland bird communities in two cross-border regions (Austria and the Czech Republic) across the former Iron Curtain that have a similar share of arable land and non-crop habitats, but markedly differ in landscape homogenization. Due to historical differences in political and socio-economic systems, the farmland in Austria is dominated by small-scale farming, whereas large-scale farming is characteristic of the Czech Republic. Using two independent datasets (i.e., point-counts and transect-counts), we found substantially (ca. 1.5-fold) higher abundance and species richness of farmland birds in Austria compared to the Czech Republic. Most of the farmland bird species (although not all) were significantly more abundant in Austria in comparison to the Czech Republic and none showed a reversed pattern. A positive association between landscape heterogeneity and farmland bird diversity suggests that conservation measures promoting small and fragmented crop fields over large ones and increasing field margins may be an effective measure to increase declining farmland biodiversity. Financial support for the agricultural production of small-scale farming agroecosystems may be an option.

Cost implications of cluster plot design choices for precise estimation of forest attributes in landscapes and forests of varying heterogeneity

Tradeoffs occur when deciding between improving forest inventory precision by increasing sample size or by augmenting cluster plot design factors like size or subplot separation distance. The nature of these tradeoffs changes with variation in type and scale of the spatial pattern of the attribute of interest. To understand the impacts of relationships between type and scale of spatial heterogeneity and cluster plot design efficiency, we constructed a factorial simulation experiment and analysed relationships among forest inventory cost, cluster plot design factors, and different spatial heterogeneity scenarios constructed via simulation. To calculate cost, we constructed a cost model that accounted for both on- and between-plot costs. We found that type and scale of heterogeneity have important implications for plot design choices. Homogeneous stands and landscapes are the least costly to inventory. Subplot area and count have stronger impacts than subplot separation on cost efficiency, particularly in landscapes with aggregated forest patterns and in stands with homogeneous tree patterns. We discuss results in the context of the physical interaction between cluster plot geometry and spatial patterns at different scales, provide computer code for simulations, and suggest principles that forest inventory cluster plot design specialists should consider when designing inventories.