Upland Land Use Research Articles

Land use composition, configuration and nutrient: Key drivers of benthic metabolism in streams

Benthic metabolism is an essential process which plays a critical role in the carbon and nutrient cycles and in the transfer of material and energy in stream ecosystems. Benthic algae are one of principal primary producers in stream food webs that converts dissolved inorganic carbon to organic matter, and algae are more palatable basal resources for aquatic consumers due to its higher unsaturated fatty acid content than terrestrial carbon. Despite the importance of algae, few studies have investigated how the benthic metabolism is influenced by distal factors, such as upland land use and landscape configuration, and proximal factors, such as stream temperature, nutrient availability, and light availability at various spatial scales. Here, we measured the benthic metabolism and proximal factors at the outlet of 14 selected sub-catchments in a subtropical river. Land use and landscape metrics at the catchment, riparian, and reach scales were processed as distal factors. Using stepwise regression models, we found that the proximal factors, such as water temperature (WT) and total phosphorus (TP), significantly increased primary production, and that nitrate-nitrogen (NO3--N), pH, and electrical conductivity (EC) decreased gross primary production (GPP). Also, TP was positively correlated with respiration (R) while NO3--N negatively impacted R. Structural equation modeling demonstrated that the patch cohesion index negatively affected GPP by restraining WT and TP at the catchment scale while the increased shape index elevated the WT and TP to promote GPP. Our results suggested that stream metabolism is vulnerable to anthropogenic disturbances, such as upland land use and landscape patterns. Thus, land use planning and administration, particularly at catchment scale, should consider how to minimize the influence of human activities on ecosystem function in streams.

Middle Holocene Lithic Technological Organization and Upland Land Use in the Upper Susitna River Basin, Alaska

ABSTRACT The middle Holocene period is marked by an apparent increase in the use of upland subsistence resources across North America. This pattern has also been observed in the uplands of central Alaska; however, we have limited understanding of the nature of upland hunter-gatherer land-use strategies during this time. This study presents a lithic technological organization analysis of three middle Holocene sites in the upper Susitna River basin, central Alaska Range, to evaluate middle Holocene land-use strategies. The Middle Holocene lithic assemblages presented here have characteristics of a low mobility land-use system in contrast with preceding periods. An important driver of middle Holocene upland land-use intensification may have been a warming climate and associated shift in vegetation patterns and caribou range. Understanding the intensity with which hunter-gatherers in the past utilized upland landscapes has implications for understanding ecological change in marginal ecosystems.

Perspectives from the Global South inform and affirm the contemporary river conservation paradigm: A commentary on Feio et al.

Perspectives from the Global South inform and affirm the contemporary river conservation paradigm: A commentary on Feio et al.

Analysis of Soil Quality Index type of land use on dry land in Blang Bintang sub-district, Aceh Besar Regency

This study aimed at examining the analysis of the soil quality index of dry land use on dry land in Blang Bintang District, Aceh Besar District. This research was conducted using a descriptive method based on the results of surveys and field observations as well as laboratory analysis. General biophysical conditions of the area and physical and chemical characteristics of the soil obtained from observations and indicators of soil quality through soil analysis in the laboratory. Soil sampling points were determined using the purposive sampling method, namely the points that have been determined on selected dry land in Blang Bintang District, Regency of Aceh Besar. The moderate soil quality index in the upland land use type is one of the reasons for the sampling of the Inceptisol soil type in the Blang Bintang sub-district, which has less fertile soil characteristics. Upland land use is the percentage of sand (57%) which is greater than the percentage of dust (36%) and clay (6%). This can be seen in the low content of C-organic (1.19), H2O, K-dd, P-available and N-total and high volume weight (1.34).

A Critical Review of the IUCN UK Peatland Programme\u2019s \u201cBurning and Peatlands\u201d Position Statement

Despite substantial contrary evidence, there has been a growing tendency to present prescribed vegetation burning as a management practice that is always damaging to peatland ecosystems in the UK. This is exemplified by the “Burning and Peatlands” position statement published by the International Union for Conservation of Nature UK Peatland Programme. Indeed, while we strongly agree with several of the statements made within this position statement, it also contains a series of unverified assertions and misleading arguments that seemingly serve to simplify the narrative and paint prescribed burning as a wholly damaging peatland management tool. Given that this position statement is published by one of the UK’s most prominent peatland conservation organisations, it is likely to be consulted when debating upland land use policy. Therefore, for the benefit of policymakers, we provide a point-by-point critical review of the “Burning and Peatlands” position statement. We also discuss several further points for researchers and policymakers to consider that are consistently ignored by those attempting to simplify the narrative about prescribed burning. Our aim in producing this discussion paper is to encourage the research and policy community to move towards an evidence-based position about prescribed burning impacts on UK peatlands.

The role of agroforestry in swidden transitions: a case study in the context of customary land tenure in Central Lao PDR

Agroforestry has been promoted as a promising model of rural development in Lao PDR (Laos), where much upland land use is in transition. Relatively little is known about the contributions of agroforestry systems to Lao farmers’ livelihoods, how these systems compare to alternatives, or the extent to which they might contribute to the national policy objective of replacing swidden agriculture. The consequences of customary land tenure for such transitions in Laos are also poorly understood. We investigated independent adoption by farmers in a Central Lao village of an agroforestry system that combines ‘yang bong’ (Persea kurzii) trees on 7-year rotations with intercrops of rice and bananas. The returns to land from this agroforestry system were more financially rewarding for farming households than swidden cultivation, demonstrating that farmers can develop land use intensification pathways that replace swidden cultivation. However, case study farmers anticipated further expansion of banana monocrops rather of agroforestry systems. In addition, the adoption of the agroforestry system has fostered wealth differentiation in the case study village, reflecting both prior and emerging inequities in the customary land tenure system. Our results indicate that it is important to closely understand the institutional and livelihood contexts of agroforestry systems, to better appreciate their role and potential in supporting sustainable land use transitions. In this case study, the intersection of customary land use practices, national policy goals and land allocation policies, new market opportunities, and farmers’ dynamic livelihood strategies, both define and constrain the contribution of agroforestry to land use transitions.

Integrated assessment, valuation and mapping of ecosystem services and dis-services from upland land use in Wales

Upland land use in Wales has high potential value in relation to the delivery of ecosystem services which is currently uncaptured. In this study we assessed the ecosystem services and dis-services generated by the two dominant land uses (forestry and agricultural) in the uplands of Wales in qualitative and monetary units. We also mapped the distribution of ecosystem services and dis-services across the two dominant land uses. Our results provide an initial baseline estimate of the supply and economic value of ecosystem services and dis-services from upland forestry and agricultural land use in Wales. The qualitative assessment showed the highest levels of ecosystem service supply were derived from forestry land use and the highest levels of ecosystem dis-services were derived from agricultural land use. The economic value of ecosystem service benefits from upland land use in Wales is £1,472.25 million year−1 and the total costs of ecosystem dis-services are £101.54 million year−1 using 2018 values. When an economic weighting is applied the per hectare economic value of ecosystem service benefits from agriculture at £1,434.02 ha−1 year−1 is higher than that of forestry at £1,261.09 ha−1 year−1 and the per hectare costs of ecosystem dis-services from agriculture at £96.10 ha−1 year−1 was marginally lower than that of forestry at £98.58 ha−1 year−1. Overall our results highlight an imbalance in the current delivery of ecosystem services from upland land use in Wales with the majority of benefits coming in the form of private benefits through provisioning services. By using systematic qualitative and economic assessment tools this study has highlighted critical data gaps and provides a basis for rebalancing ecosystem service delivery and increasing levels of public benefits through expansion of tree cover within the Welsh uplands. Our mapping highlights where land use adaption and transformation may be approached to address the imbalance in ecosystem service supply.

Effects of Wetland Presence and Upland Land Use on Wild Hymenopteran and Dipteran Pollinators in the Rainwater Basin of Nebraska, USA

Pollination is an ecosystem service that is in jeopardy globally. Decreasing trends in wild pollinator populations are primarily attributed to habitat loss and degradation. These concerns are especially apparent in the Rainwater Basin of Nebraska, USA where more than 90% of the land has been cultivated and 90% of the wetlands have been lost. We compared hymenopteran and dipteran pollinator abundance, richness, and diversity in 28 wetlands and their adjacent uplands within 3 dominant land-condition types: cropped, restored, and reference state. We used vane traps to capture local pollinator insects and sweep nets to collect insect pollinators on flowers. Vane-trap captures revealed a greater abundance, richness, and diversity of hymenopteran pollinators in uplands as compared to wetlands over the entire growing season in all land-condition types. However, net collections showed that hymenopterans foraged more in wetlands than in uplands, especially in restored wetlands. The exception was September when hymenopterans were captured in uplands more than wetlands while feeding on late season forbs. Dipteran vane-trap and sweep-net captures primarily consisted of hoverflies (Syrphidae). Hoverflies were more abundant in wetlands than uplands. All pollinators used both wetlands and uplands for resources. Thus, insect-pollinator conservation can be enhanced by promoting native forb communities and pollinator habitat through wetland restoration and the planting of buffer strips.

Stoichiometric control on riparian wetland carbon and nutrient dynamics under different land uses

Riparian wetland provides important ecosystem function, such as water filtration and nutrient retention. When land use change in upland from native forest to sugarcane cultivation have important impacts on carbon (C) and nutrient availability in downstream wetland systems. Here, we examined concentrations and stoichiometry of C and nutrients in total, labile, biomass pools in upland soil, riparian wetland and sediment along two distinct transects (sugarcane versus forest). Sugarcane cultivation significantly reduced total C, nitrogen (N), labile C and N in riparian soils by 69%, 62%, 33% and 45%, respectively, but significantly increased NO3−-N and δ15N by 99% and 56% in riparian areas. The presence of native forest resulted in significantly higher NH4+-N concentrations in downstream wetlands. Concentrations of microbial biomass C and N were generally lower, but the abundance of genes associated with nitrifiers (ammonia oxidizing bacteria and archaea) was higher in the sugarcane transect than in the forest transect. These significantly differences between two transects could be attributed to different organic inputs and biogeochemical processes associated with the different vegetation types and management practices in the upland systems. Difference in δ13C signature from the two transects further confirmed the significant influence of vegetation type on downstream wetlands. Sugarcane cultivation led to a consistent stoichiometric shift in both resource and microbial biomass towards lower C:P and N:P ratios across upland soils, wetlands and sediment, compared with the forest transect. The average total and microbial biomass C:N:P ratios in soil under sugarcane were 136:9:1 and 180:33:1, respectively. The average total and microbial biomass C:N:P ratios in soil under forest were 410:22:1 and 594:76:1, respectively. It is concluded that since microbial demand of C and nutrients is driven by the stoichiometry of the biomass, which is regulated by the resource stoichiometry, a change of resource induced by upland land use change leads to a shift in the stoichiometry of microbial biomass C, N and P.

How transnational labor migration affects upland land use practices in the receiving country: Findings from the China-Myanmar borderland

This paper examines the effects of transnational labor migration from Myanmar (Burma) on upland land use practices on the Chinese side of the China-Myanmar borderland, particularly in the context of out-migration and the aging of the local labor force. The study is based on a combined framework, with economic and geopolitical dimensions, and using in-depth fieldwork. The findings are as follows: (1) The increase of available labor from Myanmar, as a substitution for and supplementation of the outgoing local labor force that is migrating to China’s cities, helps local villagers cultivate crops, thus influencing smallholder land use. (2) This inward migration from Myanmar to China is long-term (rather than only being seasonal), based on the year-round nature and demands of China’s farming activities. (3) Due to the in-migration of labor from Myanmar, local villagers will flexibly adapt to planting cash crops that provide stable market prices. Such practices may delay the marginalization of farmland use. We argue that agricultural intensification can be achieved in the upland of the China-Myanmar borderland in the context of out- and in-migration. Smallholders can obtain profits from agricultural activities by hiring Burmese laborers, which helps to avoid a land abandonment scenario. This paper contributes to the existing body of literature on agrarian changes and rethinks agricultural growth in the upland rural society.

What Awaits Myanmar’s Uplands Farmers? Lessons Learned from Mainland Southeast Asia

Mainland Southeast Asia (MSA) has seen sweeping upland land use changes in the past decades, with transition from primarily subsistence shifting cultivation to annual commodity cropping. This transition holds implications for local upland communities and ecosystems. Due to its particular political regime, Myanmar is at the tail of this development. However, with Myanmar’s official strategy of agricultural commercialization and intensification, recent liberalization of the national economy, and influx of multinational agricultural companies, the effects on upland land transitions could come fast. We analyze the current state of upland land use in Myanmar in a socio-economic and political context, identify the dynamics in three indicator commodity crops (maize, cassava, and rubber), and discuss the state driven economic, tenurial and policy reforms that have occurred in upland areas of mainland Southeast Asian countries in past decades. We draw on these insights to contextualize our study and hypothesize about possible transition pathways for Myanmar. The transition to annual commodity cropping is generally driven by a range of socio-economic and technical factors. We find that land use dynamics for the three indicator crops are associated with market demand and thus the opening of national Southeast-Asian economies, research and development of locally suitable high yielding varieties (HYVs), and subsidies for the promotion of seeds and inputs. In contrast, promotion of HYVs in marginal areas and without adequate agricultural extension services may results in agricultural contraction and yield dis-intensification. The environmental impacts of the transition depend on the transition pathway, e.g., through large-scale plantation projects or smallholder initiatives. The agricultural development in upland MSA follows a clear diffusion pattern with transition occurring first in Thailand, spreading to Vietnam, Cambodia and Laos. While these countries point to prospects for Myanmar, we hypothesize that changes will come slow due to Myanmar’s sparse rural infrastructure, with uncertainty about tenure, in particular in areas still troubled by armed conflicts, and unwillingness of international investors to approach Myanmar given the recent setbacks to the democratization process.

Heavy metal concentrations in riparian soils along the Han River, China: The importance of soil properties, topography and upland land use

Riparian zones can act as an important sink for various contaminants, including heavy metals. The retention and accumulation of heavy metals in riparian soils varies spatially and is related to many local factors, such as soil properties, topography and land use. However, the relative importance of such factors in determining the heavy metal contamination of riparian soils remains unclear. In this study, we investigated the concentrations of 10 heavy metals (i.e., Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr and Zn) and their relationships to environmental features in 67 soil samples collected from 26 riparian sites along the Han River, China. Our results showed that there were significant and positive correlations among the concentrations of all heavy metals except for Ba, Mn and Sr. Heavy metal concentrations were, in general, positively associated with conductivity, fine substrate, carbon, nitrogen and phosphorus contents in soils but were negatively related to soil pH and density. Among the topographic conditions studied, elevation and distance from the river mouth were positively associated with the concentrations of Ba, Cd, Cr and Ni in riparian soils. Upland land use had a significant effect on the concentrations of Co, Cu and Zn. Generalized linear models revealed that soil properties, topography and land use together accounted for 11–69% of the variance in single metal concentrations, while redundancy analysis showed that such factors could explain 48% of the variance in overall metal levels. Our findings suggest that heavy metal concentrations in riparian soils are regulated not only by soil properties but also by physical characteristics such as topography and land use.

SMPIL Comments on the Long Island Nitrogen Action Plan

ABSTRACTIn early 2016, the New York State Department of Environmental Conservation, in conjunction with the Long Island Regional Planning Council, released the Conceptual Draft Scope for the Long Island Nitrogen Action Plan (LINAP).1 Pursuant to standard administrative procedures, the planners sought public comment in response to the Draft Scope Plan. SMPIL Consulting assessed and identified numerous areas for improvement and, therefore, submitted comments to the LINAP planners. These comments incorporated scientific and legal suggestions on a myriad of topics including upland land use, modeling, climate change, and adaptive management. The following article details these comments and notes the responses of the Department of Environmental Conservation as published on their Web site.

Flooding and media storms – controversies over farming and upland land-use in the UK

This viewpoint considers the impacts of media coverage of last winter’s flooding upon the farming community and the implications for their role as key partners in the delivery of landscape changes necessary to address flooding. The paper focuses on the experiences of the Pontbren farmers in Mid Wales, whose land is the site of a much-referenced study on the benefits of tree planting to address flood risk. It is argued that media sensationalism, and in many instances conflation of the science around this issue, has served to undermine good-will and engagement from farmers. Consequently, this viewpoint emphasises the importance of highlighting synergies as starting points for dialogue; as is the case when negotiating all forms of landscape multifunctionality.

Upslope development of a tidal marsh as a function of upland land use.

To thrive in a time of rapid sea-level rise, tidal marshes will need to migrate upslope into adjacent uplands. Yet little is known about the mechanics of this process, especially in urbanized estuaries, where the adjacent upland is likely to be a mowed lawn rather than a wooded natural area. We studied marsh migration in a Long Island Sound salt marsh using detailed hydrologic, edaphic, and biotic sampling along marsh-to-upland transects in both wooded and lawn environments. We found that the overall pace of marsh development was largely unaffected by whether the upland being invaded was lawn or wooded, but the marsh-edge plant communities that developed in these two environments were quite different, and some indicators (soil salinity, foraminifera) appeared to migrate more easily into lawns. In addition, we found that different aspects of marsh structure and function migrated at different rates: Wetland vegetation appeared to be a leading indicator of marsh migration, while soil characteristics such as redox potential and surface salinity developed later in the process. We defined a 'hydrologic migration zone', consisting of elevations that experience tidal inundation with frequencies ranging from 20% to 0.5% of high tides. This hydrologically defined zone - which extended to an elevation higher than the highest astronomical tide datum - captured the biotic and edaphic marsh-upland ecotone. Tidal inundation at the upper border of this migration zone is highly variable over time and may be rising more rapidly than mean sea level. Our results indicate that land management practices at the upland periphery of tidal marshes can facilitate or impede ecosystem migration in response to rising sea level. These findings are applicable to large areas of tidal marsh along the U.S. Atlantic coast and in other urbanized coastal settings.

Terrestrial groundwater and nutrient discharge along the 240-km-long Aquitanian coast

We collected samples from sea water, runnel water, beach pore waters, water from the unconfined surficial aquifer discharging at the beach face, groundwater, and rainwater from the Aquitanian coast in order to determine the flux of dissolved inorganic nitrogen (DIN), phosphorus and silica from terrestrial submarine groundwater discharge (SGD). The flux of fresh groundwater was obtained from a water balance calculation based on precipitation and evapotranspiration and assessment of the coastal watershed from hydrograph separation. Waters with intermediate salinities between sea water and freshwaters are found all along the 240-km-long coast, indicating that SGD is ubiquitous. The estimated fresh water flux is 2.25m3d−1m−1 longshore. Terrestrial SGD provides a DIN flux of 9·106mol each year to the adjacent coastal zone. This flux is about four times lower than the release of DIN due to tidally driven saline SGD. The freshwater DIN flux is low because the upland land use consists almost exclusively of pine forest. Dissolved organic nitrogen represents more than 60% of the total dissolved nitrogen flux. Dissolved iron, phosphorus and silica have much higher concentrations in the anoxic forest aquifer than in the fresh-water end-member of the subterranean estuary sampled in the upper beach aquifer. This suggests that the salinity gradient of the estuary does not correspond to a redox gradient. The redox front between anoxic groundwater and fresh oxic waters occurs below the soil-depleted foredune/yellow dune. Anoxic P- and Si-rich waters seep directly on the beach face only in the north Gironde, where the foredunes are eroded. This study reveals the role of the sandy foredune aquifer in biogeochemical fluxes from SGD, which is to dilute and oxidize waters from the unconfined surficial upland aquifer.

Both habitat change and local lek structure influence patterns of spatial loss and recovery in a black grouse population

AbstractLand use change is a major driver of declines in wildlife populations. Where human economic or recreational interests and wildlife share landscapes this problem is exacerbated. Changes in UK black grouse Tetrao tetrix populations are thought to have been strongly influenced by upland land use change. In a long‐studied population within Perthshire, lek persistence is positively correlated with lek size, and remaining leks clustered most strongly within the landscape when the population is lowest, suggesting that there may be a demographic and/or spatial context to the reaction of the population to habitat changes. Hierarchical cluster analysis of lek locations revealed that patterns of lek occupancy when the population was declining were different to those during the later recovery period. Response curves from lek‐habitat models developed using MaxEnt for periods with a declining population, low population, and recovering population were consistent across years for most habitat measures. We found evidence linking lek persistence with habitat quality changes and more leks which appeared between 1994 and 2008 were in improving habitat than those which disappeared during the same period. Generalised additive models identified changes in woodland and starting lek size as being important indicators of lek survival between declining and low/recovery periods. There may also have been a role for local densities in explaining recovery since the population low point. Persistence of black grouse leks was influenced by habitat, but changes in this alone did not fully account for black grouse declines. Even when surrounded by good quality habitat, leks can be susceptible to extirpation due to isolation.

Impacts of climate change on land-use and wetland productivity in the Prairie Pothole Region of North America

Wetland productivity in the Prairie Pothole Region (PPR) of North America is closely linked to climate. A warmer and drier climate, as predicted, will negatively affect the productivity of PPR wetlands and the services they provide. The effect of climate change on wetland productivity, however, will not only depend on natural processes (e.g., evapotranspiration), but also on human responses. Agricultural land use, the predominant use in the PPR, is unlikely to remain static as climate change affects crop yields and prices. Land use in uplands surrounding wetlands will further affect wetland water budgets and hence wetland productivity. The net impact of climate change on wetland productivity will therefore depend on both the direct effects of climate change on wetlands and the indirect effects on upland land use. We examine the effect of climate change and land-use response on semipermanent wetland productivity by combining an economic model of agricultural land-use change with an ecological model of wetland dynamics. Our results suggest that the climate change scenarios evaluated are likely to have profound effects on land use in the North and South Dakota PPR, with wheat displacing other crops and pasture. The combined pressure of land-use and climate change significantly reduces wetland productivity. In a climate scenario with a +4 °C increase in temperature, our model predicts that almost the entire region may lack the wetland productivity necessary to support wetland-dependent species.

汉江上游金水河悬浮物及水体碳氮稳定同位素组成特征

Nitrogen and carbon are important elements regulating the structure and function of river ecosystems; therefore, determining their sources has important implications for integrated river basin management. Since physical processes and human activities can lead to different isotopic signatures in organic matter, the characteristics of the stable isotopes of carbon and nitrogen could be used to determine carbon and nitrogen sources in riverine systems. The upper Han River is the water source area for the Middle Route of the South-to-North Water Diversion Project (MR-SNWTP); hence, identifying pollutant origins in the riverine system is critically important for the interbasin water transfer project. In this study, we investigated the δ13C and δ15N values of particulate organic matter (POM) and δ15 N values of nitrogen including nitrate nitrogen (N-NO-3) and ammonium nitrogen (N-NH+4) to trace the sources of organic matter in the river ecosystem. The study site was the Jinshui River with a length of 87 km and drainage area of 730 km2 in the upper Han River during 2012— 2013. Furthermore, we measured chlorophyll content, turbidity, and the concentrations of N-NH+4 and N-NO-3 in the river system using YSI 6920. The results demonstrated spatial variability in POM, with higher content in the moderately disturbed zone and intensely disturbed zone than in the slightly disturbed zone. The concentration of ammonium showed seasonality with minimal concentrations (0.07 mg/ L) in the spring and maximum concentrations (0.45 mg/ L) in winter, whereas the maximum concentration of nitrate was 0.44 mg/ L in winter and the minimal value was 0.08 mg/ L in summer. The carbon isotope value of POM also showed an obvious seasonality, in decreasing order of spring, summer, winter, and fall. The turbidity reached its maximum in summer from the heavily rainfall in the same season due to the monsoon climate. The Chl/ turbidity ratio could be used to identify the contribution of algae to the total particulate organic materials in the river. Algae, which have a higher carbon isotope value (-21.18%--27.14%) than terrestrial organic matter (-27.34%--28.83%), were the main source of POM. POM with an N isotope range of -8.03%-14.5% primarily originated from soil organic matter and plankton. The dissolved nitrate with isotope ranges of -5.86%-17.20% for ammonium and -1.48%-15.86% for nitrogen in the riverine system primarily originated from precipitation, plankton, and fertilizer. Also, larger values for δ15 N-NH+4 and δ15N-NO-3 were observed in the growing season (i.e., spring/ summer), which was possibly due to the seasonally higher chlorophyll concentration (i.e., high algae density in the river). Additionally, the low nitrate stable isotope value and low concentration of ammonium and nitrate in summer were possibly due to nitrification and alga uptake in the riverine system. Moreover, microbial denitrification could increase the nitrate stable isotope value and decrease nitrate concentrations; our results showed that the maximum δ15 N value appeared in winter due to the low temperatures. The research implies that N-loading from the catchment reflects the upland land use pattern along the riverine system, and the isotopic technique could be an effective approach for quantifying pollutant sources in river systems.

Upland land use predicts population decline in a globally near‐threatened wader

Summary Changes in large‐scale land use may fragment and degrade habitats, affecting animal species adapted to these habitats. In the UK uplands for example, changes in sheep and game management, and afforestation, have altered the configuration of internationally important moorland habitat and are predicted to have increased predation pressure for a globally unique suite of breeding birds of international conservation importance. Some of these upland bird species have declined, with particular concern over ground‐nesting waders. Using resurveys of the rapidly declining Eurasian curlew Numenius arquata as a focal species of global conservation concern, we investigate whether upland land use predicts low nesting success and population decline. Curlew population changes over an 8‐ to 10‐year period were positively related to gamekeeper density (a surrogate of predator control intensity) and inversely to the area of woodland surrounding sites, as a likely source of predators to adjacent open ground. Model predictions suggest that increasing woodland cover from 0% to 10% of the land area within 1 km of populated sites requires an increase in human predator control effort of about 48%, to a level associated with high‐intensity grouse production, to achieve curlew population stability. Curlew nesting success, known to be a key driver of population trends, was also positively related to gamekeeper density and inversely to woodland area surrounding sites, providing a plausible mechanistic link between land use and population change. Synthesis and applications. Upland land use is associated with curlew declines, with predation a likely mechanism, and this may apply to other breeding waders. The removal of isolated woodland plantations from otherwise unafforested landscapes may help reduce predation pressure across a range of systems including moorland. However, direct predator control may also be important to conserve ground‐nesting birds in these landscapes, for example, where moorland management and forestry coexist as major land uses. Predator control may also mitigate climate change effects by enhancing wader productivity, particularly where climate effects coincide with changing land use. Emerging land uses in open landscapes, including native woodland restoration and wind farms, require careful siting to minimize further impacts on open‐area breeding birds.