Synergistic effects of climate and land cover: grassland birds are more vulnerable to climate change

Context

Climate change is not occurring over a homogeneous landscape and the quantity and quality of available land cover will likely affect the way species respond to climate change. The influence of land cover on species’ responses to climate change, however, is likely to differ depending on habitat type and composition.

Objectives

Our goal was to investigate responses of forest and grassland breeding birds to over 20 years of climate change across varying gradients of forest and grassland habitat. Specifically, we investigated whether (i) increasing amounts of available land cover modify responses of forest and grassland-dependent birds to changing climate and (ii) the effect of increasing land cover amount differs for forest and grassland birds.

Methods

We used Bayesian spatially-varying intercept models to evaluate species- and community-level responses of 30 forest and 10 grassland birds to climate change across varying amounts of their associated land cover types.

Results

Responses of forest birds to climate change were weak and constant across a gradient of forest cover. Conversely, grassland birds responded strongly to changing climatic conditions. Specifically, increasing temperatures led to higher probabilities of localized extinctions for grassland birds, and this effect was intensified in regions with low amounts of grassland cover.

Conclusions

Within the context of northeastern forests and grasslands, we conclude that forests serve as a possible buffer to the impacts of climate change on birds. Conversely, species occupying open, fragmented grassland areas might be particularly at risk of a changing climate due to the diminished buffering capacity of these ecosystems.

     

Changing landscapes to accommodate for climate change impacts: a call for landscape ecology

Predictions of climate change suggest major changes in temperature, rainfall as well as in frequency and timing of extreme weather, all in varying degrees and patterns around the world. Although the details of these patterns changes are still uncertain, we can be sure of profound effects on ecological processes in and functioning of landscapes. The impact of climate change will affect all types of land use, ecosystem services, as well as the behavior of humans. The core business of Landscape Ecology is the interaction of landscape patterns and processes. Most of these interactions will be affected by changing climate patterns, so clearly within the focus of our science. Nevertheless, climate change received little attention from landscape ecologists. Are we missing the boat? Why is it that our science does not contribute to building a knowledge base to help solving this immense problem? Why is there so little attention paid to adaptation of landscape to climate change? With this editorial article IALE would like to receive inputs from the Landscape Ecology scientific community in related research on adaptation of landscapes to climate change, on tools or approaches to help landscape planners and stakeholders to this new challenge where landscape ecology can play a key role.     

Assessing the potential impacts of climate change on the alpine habitat suitability of Japanese stone pine (Pinus pumila)

To assess the potential distribution of Pinus pumila, a dominant species of the Japanese alpine zone, and areas of its habitats vulnerable to global warming, we predicted potential habitats under the current climate and two climate change scenarios (RCM20 and MIROC) for 2081–2100 using the classification tree (CT) model. The presence/absence records of P. pumila were extracted from the Phytosociological Relevé Database as response variables, and five climatic variables (warmth index, WI; minimum temperature for the coldest month, TMC; summer precipitation, PRS; maximum snow water equivalent, MSW; winter rainfall, WR) were used as predictor variables. Prediction accuracy of the CT evaluated by ROC analysis showed an AUC value of 0.97, being categorized as “excellent”. We designated Third Mesh cells with an occurrence probability of 0.01 or greater as potential habitats and further divided them into suitable and marginal habitats based on the optimum threshold probability value (0.06) in ROC analysis. Deviance weighted scores revealed that WI was the largest contributing factor followed by MSW. Changes in habitat types from the current climate to the two scenarios were depicted within an observed distribution (Hayashi’s distribution data). The area of suitable habitats under the current climate decreased to 25.0% and to 14.7% under the RCM20 and MIROC scenarios, respectively. Suitable habitats were predicted to remain on high mountains of two unconnected regions, central Honshu and Hokkaido, while they were predicted to vanish in Tohoku and southwestern Hokkaido. Thus P. pumila populations in these regions are vulnerable to climate change.     

Effects of structural and functional habitat gaps on breeding woodland birds: working harder for less

The effects of habitat gaps on breeding success and parental daily energy expenditure (DEE) were investigated in great tits (Parus major) and blue tits (Cyanistes caeruleus) in urban parkland (Cardiff, UK) compared with birds in deciduous woodland (eastern England, UK). Tree canopy height, the percentage of gap in the canopy and the percentage of oak (in the wood only) within a 30 m radius of nest boxes were obtained from airborne remote-sensed data. Breeding success was monitored and parental DEE (great tits: both habitats; blue tits: park only) was measured using doubly labelled water in birds feeding young. In the park, mean (±SD) tree height (7.5 ± 4.7 m) was less than in the wood (10.6 ± 4.5 m), but the incidence of gaps (32.7 ± 22.6%) was greater (9.2 ± 14.7%). Great tits and blue tits both reared fewer young in the park and chick body mass was also reduced in park-reared great tits. Park great tits had a higher DEE (86.3 ± 12.3 kJ day⁻¹) than those in the wood (78.0 ± 11.7 kJ day⁻¹) and, because of smaller brood sizes, worked about 64% harder for each chick reared. Tits in the park with more than about 35% gap around their boxes had higher DEEs than the average for the habitat. In the wood, great tits with less oak around their boxes worked harder than average. Thus structural gaps, and functional gaps generated by variation in the quality of foraging habitat, increased the costs of rearing young. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The role of land use and land cover change in climate change vulnerability assessments of biodiversity: a systematic review

Landscape Ecology - For many organisms, responses to climate change (CC) will be affected by land-use and land-cover changes (LULCC). However, the extent to which LULCC is concurrently...     

Modelling water stress to urban amenity grass in Manchester UK under climate change and its potential impacts in reducing urban cooling

It is well known that the evapotranspiration of vegetation such as grass can help to reduce the urban heat island. However, the cooling can be reduced or lost in summer droughts, when soils dry out, an effect that is likely to be more pronounced and occur for longer as climate change proceeds. Here we modelled the likely effect of climate change on the droughting of amenity grass in Greater Manchester, UK. We used a simple Bucket model, with data on Greater Manchester's soils, and its current and anticipated precipitation and potential evapotranspiration. This was experimentally validated by measuring the weight loss of ryegrass turves. The results show a dramatic increase in drought, especially in the drier south west of the conurbation, with some areas exhibiting reduced evapotranspiration for 3–5 months by the 2080s, and evapotranspiration reducing by over a half for 1–2 months, in an average year. Such changes could have large effects on the urban heat island, resulting in increases in surface temperatures of up to 15 °C in areas where grass accounts for a large proportion of the surface cover. The problem could be overcome by irrigation of grassland so that it will continue to provide cooling, and it is shown that runoff from large rainfall events could in theory provide adequate irrigation water, particularly in highly built-up areas.     

Irrigation induced change in vegetation and evapotranspiration in the Central Valley of California

Landscape changes in the Central Valley of California, USA, have been dramatic over the past 100 years. Irrigated agriculture has replaced natural communities of California prairie, riparian forest, tule marsh, valley oak savannah, and San Joaquin saltbrush. This paper addresses the implication of vegetation change on evapotranspiration as a consequence of these changes. It was found that an increase in irrigated agriculture and a 60% reduction in the aerial extent of native vegetation has not produced significant changes in the moisture transfer to the atmosphere. The apparent reason for this result is that irrigated agriculture has substituted one actively transpiring surface for another and, therefore, has not significantly altered the transpiration flux of the landscape.     

气候资源变化对陕西省猕猴桃生产的影响分析

基于陕西省关中地区的陈仓、眉县、杨凌、周至、户县、长安、灞桥、蓝田、临渭、华阴、华县和陕南地区的城固、洋县、勉县、佛坪等15个称猴桃主产县区1961-2010年的气象资料,利用趋势分析、线性回归、突变检验等气候统计方法,重点分析该地区50年来影响猕猴桃生长发育的年平均气温、负积温、≥5℃年有效积温、≥10℃年有效积温、年降水量、4一10月猕猴桃生长期降水量等光热水资源的年际、周期以及时空分布变化趋势的规律与特点,分析了50年来气候资源变化对陕西省猕猴桃生产的影响。结果表明,猕猴桃主产县区热量资源增加明显,年平均气温和≥10℃年有效积温总体上呈现上升趋势,种植区初霜日推迟、终霜日提前,无霜期呈明显增加趋势。降水变化趋势不明显,而年日照时数呈现明显减少趋势。除降水外,光热资源的变化均发生了突变,且关中地区的变化比陕南地区较为显著。从气候变化的特点上看,关中地区的光热资源变化增加了称猴桃生产的不确定性,而汉中盆地的气候资源变化趋势相对较弱,建议在该区域可适度增加猕猴桃种植规模。同时,气候变化的加剧,极端天气事件明显增多,猕猴桃的萌芽期冻害、高温热害等由于全球变化引起的气象灾害发生频率也呈现明显增加趋势,为猕猴桃优质生产带来了很大的不确定性,因此后期针对猕猴桃主要气象灾害风险进行研究是关注的重点。     

Linking land change model evaluation to model objective for the assessment of land cover change impacts on biodiversity

Landscape Ecology - Evaluation of land cover change (LCC) is commonly done at the pixel level; however, the model’s purpose may be relevant at a different grain size. Thus, the same...     

气候变化背景下陇东塬区‘红富士’苹果始花期研究

【目的】分析苹果始花期对气候变化的响应,提取主要影响气象因子,并提出优势苹果花期预报方法;为苹果开花期气象灾害防御和管理措施的调整提供科学依据。【方法】采用偏最小二乘回归法对西峰农业气象试验站多年观测的苹果始花期与光、热、水气象因子进行分析,并开展了苹果始花期预测。【结果】苹果始花期的早晚与2月下旬至4月上旬的旬平均气温及3月平均气温呈显著负相关;苹果开花日期与积温呈现显著的相关性,≥0℃、≥5℃积温越大或0℃积温越小,花期出现越早,反之则迟;说明气温升高,开花日期出现早,反之则迟。苹果始花期与稳定通过10℃初日接近,较稳定通过5℃初日晚超过20 d。利用偏最小二乘回归模型预报苹果始花期,预测日期与实际日期相符率为97%。【结论】影响陇东苹果开花早晚的主要影响因素是热量因子,日照次之,降水影响最小,气候变暖和高光照使苹果始花期提前。偏最小二乘回归模型预测苹果始花期较传统回归模型和线性分析法预报苹果始花期更为科学。     

Sensitivity and future exposure of ecosystem services to climate change on the Tibetan Plateau of China

Context

Climate change has imposed tremendous impacts on ecosystem services. Recent attempts to quantify such impacts mainly focused on a basin or larger scale, or used limited time periods that largely ignore observations of long-term trends at a fine resolution, thereby affecting the recognition of climate change’s effect on ecosystem services.

Objectives

This study conducts a detailed and spatially explicit recognition of climate change’s effect on ecosystem services and provides an intuitive map for decision-making and climate change adaptation planning.

Methods

We used long-term time series of ecosystem service assessments and various future climate scenarios to quantify the sensitivity and future exposure of ecosystem services to climate change on the Tibetan Plateau.

Results

Carbon sequestration (CS) and habitat quality experience significant growth, while water retention did not show any trend. Sensitivity patterns of these ecosystem services vary largely. For CS, more than half of the pixels showed a positive sensitivity to climate change, even though the degree of sensitivity is not high. There is substantial spatial heterogeneity in the exposure of ecosystem services to future climate changes, and high levels of future climate change increase the intensity of exposure.

Conclusions

This study illustrates the complex spatial association between ecosystem services and climatic drivers, and these findings can help optimize local response strategies in the context of global warming. For example, the existing protected areas have notable conservation gaps for disturbance of future climate change on ecosystem services, especially in the southeastern part of the study area.

     

High and dry: high elevations disproportionately exposed to regional climate change in Mediterranean-climate landscapes

Context

Predicting climate-driven species’ range shifts depends substantially on species’ exposure to climate change. Mountain landscapes contain a wide range of topoclimates and soil characteristics that are thought to mediate range shifts and buffer species’ exposure. Quantifying fine-scale patterns of exposure across mountainous terrain is a key step in understanding vulnerability of species to regional climate change.

Objectives

We demonstrated a transferable, flexible approach for mapping climate change exposure in a moisture-limited, mountainous California landscape across 4 climate change projections under phase 5 of the Coupled Model Intercomparison Project (CMIP5) for mid-(2040–2069) and end-of-century (2070–2099).

Methods

We produced a 149-year dataset (1951–2099) of modeled climatic water deficit (CWD), which is strongly associated with plant distributions, at 30-m resolution to map climate change exposure in the Tehachapi Mountains, California, USA. We defined climate change exposure in terms of departure from the 1951–1980 mean and historical range of variability in CWD in individual years and 3-year moving windows.

Results

Climate change exposure was generally greatest at high elevations across all future projections, though we encountered moderate topographic buffering on poleward-facing slopes. Historically dry lowlands demonstrated the least exposure to climate change.

Conclusions

In moisture-limited, Mediterranean-climate landscapes, high elevations may experience the greatest exposure to climate change in the 21st century. High elevation species may thus be especially vulnerable to continued climate change as habitats shrink and historically energy-limited locations become increasingly moisture-limited in the future.