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1.
2.
Context

Species distribution modelling is a common tool in conservation biology but two main criticisms remain: (1) the use of simplistic variables that do not account for species movements and/or connectivity and (2) poor consideration of multi-scale processes driving species distributions.

Objectives

We aimed to determine if including multi-scale and fine-scale movement processes in SDM predictors would improve accuracy of SDM for low-mobility amphibian species compared with species-level analysis.

Methods

We tested and compared different SDMs for nine amphibian species with four different sets of predictors: (1) simple distance-based predictors; (2) single-scale compositional predictors; (3) multi-scale compositional predictors with a priori selection of scale based on knowledge of species mobility and scale-of-effect; and (4) multi-scale compositional predictors calculated using a friction-based functional grain to account for resource accessibility with landscape resistance to movement.

Results

Using friction-based functional grain predictors produced slight to moderate improvements of SDM performance at large scale. The multi-scale approach, with a priori scale selection, led to ambiguous results depending on the species studied, in particular for generalist species.

Conclusion

We underline the potential of using a friction-based functional grain to improve SDM predictions for species-level analysis.

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3.
Influence of landscape structure on local and regional climate   总被引:21,自引:1,他引:20  
This paper discusses the physical linkage between the surface and the atmosphere, and demonstrates how even slight changes in surface conditions can have a pronounced effect on weather and climate. Observational and modeling evidence are presented to demonstrate the influence of landscape type on the overlying atmospheric conditions. The albedo, and the fractional partitioning of atmospheric turbulent heat flux into sensible and latent fluxes is shown to be particularly important in directly affecting local and regional weather and climate. It is concluded that adequate assessment of global climate and climate change cannot be achieved unless mesoscale landscape characteristics and their changes over time can be accurately determined.  相似文献   

4.
We examined factors that affect egg distributions of amphibians, which are currently declining globally, in urban areas. We counted the number of egg masses of two amphibian species (Hynobius retardatus and Rana pirica) in ponds in urban green spaces during two years (2011 and 2012) and investigated the effects of local and landscape factors on them. Forest area in green spaces and pond area had positive effects, and distance from continuous forests in the suburbs and the rate of pond shore protection had negative effects on the number of eggs. Among these factors, distance from continuous forests and pond area had strong effects on egg distributions. These results suggest the importance of water habitat size and the need for colonization by amphibians from surrounding continuous forests. To conserve urban amphibian assemblages, the preservation of ponds with sufficient area and continuous forests close to urban habitats would be important.  相似文献   

5.
The contribution to urban green space by private or domestic gardens in residential zones was investigated in the city of Sheffield, UK, as part of a wider study of the garden resource and its associated biodiversity. The attributes of 61 gardens, including patterns of landcover and vegetation cover, were explored in relation to housing characteristics and the nature of the surrounding landscape. The number of surrounding houses, and the areas of buildings and of roads were negatively correlated with garden area. The proportion of a housing parcel comprising garden increased with parcel size, although the proportion that was rear garden remained relatively constant. Garden size played an overwhelming role in determining garden composition: larger gardens supported more landcovers, contained greater extents of three-quarters of the recorded landcovers, and were more likely to contain trees taller than 2 m, vegetable patches, and composting sites. Unvegetated landcovers made greater proportional contributions as garden size declined. All categories of vegetation canopy increased with garden size, and large gardens supported disproportionately greater cover above 3 m. House age was a less significant factor determining garden landcover. Gardens of newer houses were more likely to occur towards the edge of the urban area, and older properties, that contained fewer hedges, possessed less canopy between 2–3 m. The extent and occurrence of different landcovers in gardens, and their consequences for wildlife, are considered for residential patches in urban areas. The implications for urban planners are discussed.  相似文献   

6.
Dyderski  Marcin  Żarnowiec  Jan  Stebel  Adam  Chmura  Damian 《Landscape Ecology》2022,37(7):1871-1884
Landscape Ecology - The spread of invasive bryophytes in Central Europe started in the 2nd half of the twentieth century. However, still it is not known which climatic and land-use factors shape...  相似文献   

7.
Cao  Qian  Liu  Yupeng  Georgescu  Matei  Wu  Jianguo 《Landscape Ecology》2020,35(6):1269-1290
Landscape Ecology - Studies have shown that land use and land cover change (LUCC) has myriad impacts on local and regional climate. Synthesizing the recent findings in this field helps advance...  相似文献   

8.
Wetlands, carbon, and climate change   总被引:3,自引:0,他引:3  
Wetland ecosystems provide an optimum natural environment for the sequestration and long-term storage of carbon dioxide (CO2) from the atmosphere, yet are natural sources of greenhouse gases emissions, especially methane. We illustrate that most wetlands, when carbon sequestration is compared to methane emissions, do not have 25 times more CO2 sequestration than methane emissions; therefore, to many landscape managers and non specialists, most wetlands would be considered by some to be sources of climate warming or net radiative forcing. We show by dynamic modeling of carbon flux results from seven detailed studies by us of temperate and tropical wetlands and from 14 other wetland studies by others that methane emissions become unimportant within 300 years compared to carbon sequestration in wetlands. Within that time frame or less, most wetlands become both net carbon and radiative sinks. Furthermore, we estimate that the world’s wetlands, despite being only about 5–8 % of the terrestrial landscape, may currently be net carbon sinks of about 830 Tg/year of carbon with an average of 118 g-C m?2 year?1 of net carbon retention. Most of that carbon retention occurs in tropical/subtropical wetlands. We demonstrate that almost all wetlands are net radiative sinks when balancing carbon sequestration and methane emissions and conclude that wetlands can be created and restored to provide C sequestration and other ecosystem services without great concern of creating net radiative sources on the climate due to methane emissions.  相似文献   

9.
Vegetation plays a critical role in climate regulation by cooling and humidifying urban regions. The climate regulation capacity of vegetation varies in different seasons, and its association with the coupling of temperature and humidity remains poorly understood. Here, we investigated the climate regulation potential of vegetation by establishing a set of indices, namely, cooling intensity (CI), cooling efficiency (CE), humidifying intensity (HI), and humidifying efficiency (HE), using continuous decadal field measurements (2013–2022) of temperature and humidity in vegetation and built-up areas in Beijing, China. Additionally, we examined the coupling effect and threshold of cooling and humidification using these indices. Climate regulation by vegetation was insignificant at night. However, the daytime results were as follows: (1) the maximum CI and CE were similar in four seasons, and their ratio was 2:3:2:1 in spring, summer, autumn, and winter, respectively; (2) the ratio of maximum HI was 4:10:7:3, whereas that of the maximum HE was 7:8:7:2 in spring, summer, autumn, and winter, respectively; and (3) the coupling of ambient temperature and humidity affected the climate regulation of vegetation. The CE and HE of vegetation increased significantly when the ambient temperature exceeded 15.1 °C and 8.5 °C, respectively. The CI and HI decreased with increasing humidity and were highest in a high temperature and low humidity ambient environment. Our study presents scientific insights into vegetation cooling and humidifying effects under different climate backgrounds and provides an enhanced understanding of the coping ability of vegetation in a severe heat island environment.  相似文献   

10.
Although the effects of climate change on species distributions have received considerable attention, land-use change continues to threaten wildlife by contributing to habitat loss and degradation. We compared projected spatial impacts of climate change and housing development across a range of housing densities on California’s birds to evaluate the relative potential impacts of each. We used species-distribution models in concert with current and future climate projections and spatially explicit housing-development density projections in California. We compared their potential influence on the distributions of 64 focal bird species representing six major vegetation communities. Averaged across GCMs, species responding positively to climate change were projected to gain 253,890 km2 and species responding negatively were projected to lose 335,640 km2. Development accounted for 32 % of the overall reductions in projected species distributions. In terms of land area, suburban and exurban development accounted for the largest portion of land-use impacts on species’ distributions. Areas in which climatic suitability and housing density were both projected to increase were concentrated along the foothills of the Sierra Nevada and areas of the north coast. Areas of decreasing climatic suitability and increasing housing density were largely concentrated within the Central Valley. Our analyses suggest that the cumulative effects of future housing development and climate change will be large for many bird species, and that some species projected to expand their distributions with climate change may actually lose ground to development. This suggests that a key climate change adaptation strategy will be to minimize the impacts of housing development. To do this effectively, comprehensive policies to guide land use decisions are needed at the broader scales of climate change.  相似文献   

11.
空间诱变育种及其在瓜类上的应用   总被引:7,自引:0,他引:7  
空间诱变育种(或航天育种)是航天技术与现代生物技术、常规育种技术相结合的新育种技术。论述了空间诱变育种的概念、方法、机理、特点及国内外研究概况,并分析了空间诱变育种技术在瓜类育种上的应用,对其前景进行了展望。  相似文献   

12.
Distribution patterns of wild species are affected by environmental variables, such as climate, anthropogenic land use or habitat quality, which act simultaneously at different scales. To examine the relative importance of particular factors and scales on population response we investigated the speckled wood butterfly Pararge aegeria (L.) as a model organism occupying semi-natural habitats. Its distribution was recorded in 23 study sites (5×5 km) over a 2 year study period. The sites were located in agricultural landscapes within seven Temperate European countries. Environmental predictors were mapped at a local and a regional scale. Logistic regression models were then developed to represent humid (beneficial) and dry (adverse) weather conditions during larval development. The humid year model predicted that P. aegeria is equally but generally not very dependent on local and regional factors, resulting in generally high occurrence probabilities. In contrast, the dry year model predicted severe restrictions of P. aegeria to both high quality patches and landscapes with beneficial structural and climatic preconditions. As both models resulted in entirely different predictions, our study showed that the sensitivity of P. aegeria to local and landscape features might change, and that factors of less importance could easily become limiting factors. The results stress that high quality landscape is important at both the local and regional scale even for species that are considered relatively robust. They also sound a note of caution when predictions about population response for management purposes are based on just a single or a few year(s) of observation.  相似文献   

13.
Despite growing knowledge of ecosystem services (ES), and heightened awareness of their political and socio-economic relevance, mainstreaming and implementing ES in landscape planning and decision-making are still in their infancy. The objective of this special issue, therefore, is to explore requirements for, approaches to, and potential impacts of, integrating ES in landscape planning and management. The issue includes three key research themes: (i) Requirements and interests of planners and decision-makers for integrating ES in different application contexts, (ii) Approaches to applying ES in (participatory) planning, and (iii) Potential impacts of integrating ES in policy and decision-making. These themes are addressed by 12 papers that refer to case studies in Africa, Australia, and Europe. Four lessons are highlighted: (i) Information on ES is considered useful by many practitioners, but the type, production and communication of ES information need to be adapted to the specific context of a planning case; (ii) A broad range of approaches are available for integrating the ES concept in (participatory) planning with different and complementary contributions to decision-support; (iii) Effectively integrating ES in planning requires careful scoping of the context, objectives and capacities; (iv) Integrating ES in planning can effectively support the co-production of relevant knowledge and the collaboration of diverse actors. A new research field of ‘Planning-for-ES Science’ is emerging which focuses on, among other issues, the critical evaluation of real-world case studies of applying the ES concept in different fields of practice.  相似文献   

14.
试验表明,‘龙柱’碧桃嫁接繁育时,切接生产一级苗比例高达33. 4%,在4月上中旬气温较高时,采用蜡封、粗细0. 8~1. 0 cm接穗,成活率最高为90. 8%,适宜生产高端景观绿化苗;芽接时,采用砧穗粗细匹配、新采接穗、避开雨天、7月上旬~8月下旬适于嫁接,成活率高达94.6%,单株平均净收入为3.23元,高于切接苗0.19元/株,经济效益好。  相似文献   

15.

Context

The scale of environmental relationships is often inferred through the use of species distribution models. Yet such models are frequently developed at two distinct scales. Coarse-scale models typically use information-poor (e.g., presence-only) data to predict relative distributions across geographic ranges, whereas fine-scale models often use richer information (e.g., presence–absence data) to predict distributions at local to landscape scales.

Objectives

We unite presence–absence and presence-only data to predict occurrence of species, what we refer to as integrated distribution models. We determine if integrated models improve predictions of species distributions and identification of characteristic spatial scales of environmental relationships relative to presence–absence modeling and ensemble modeling that averages predictions from separate presence-only and presence–absence models.

Methods

We apply recent advances in integrated distribution models to predict Sherman’s fox squirrel (Sciurus niger shermani) distribution in north-central Florida. Presence-only data were collected through a citizen-science program across its geographic range, while presence–absence data were collected using camera trapping surveys across 40 landscapes.

Results

Integrated models estimated environmental relationships with greater precision and identified larger characteristic scales for environmental relationships than using presence–absence data alone. In addition, integrated models tended to have greater predictive performance, which was more robust to the amount of presence–absence and presence-only data used in modeling, than presence–absence and ensemble models.

Conclusions

Integrated distribution models hold much potential for improving our understanding of environmental relationships, the scales at which environmental relationships operate, and providing more accurate predictions of species distributions. Many avenues exist for further advancement of these modeling approaches.
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16.
Landscape Ecology - Landscape and local factors govern tree regeneration across heterogeneous post-fire forest environments. But their relative influence is unclear—limiting the degree that...  相似文献   

17.
李(plum)是重要的核果类果树之一,属蔷薇科(Rosaceae)李属(Prunus),我国是中国李(Prunus salicina L.)的起源地,有着悠久的栽培历史、丰富的种质资源和广泛的地区分布。中国李也是世界范围内商业化栽培的种之一,主要供鲜食,具有较高的经济价值和生态价值。我国李年产量占世界总产量的50%以上,是世界李生产第一大国。原产我国的李地方品种类型多样,果实口感佳、香味浓郁,深受消费者青睐,在悠久的栽培过程中保留、筛选了大批适应当地气候特点和具有鲜明特色的李品种,对我国李产业和地方经济发展起到了积极的推动作用。为了满足果树生产中对李新品种的需求,我国育种工作者从上世纪五六十年代开始了以抗寒、丰产、优质、观赏为目标的李育种工作,主要集中在中国李育种上。据不完全统计,截至2017年,我国自主育成、通过品种审定并正式发表的李品种有64个,东北三省科研单位育成品种37个,占总数的57.81%,是我国李育种的主要育种单位。纵观我国历年育成的李品种,主要是通过实生和杂交方式获得,以地方品种实生和中国李杂交为主,芽变品种占少数,近几年通过地方品种与国外品种杂交培育出一批优良新品种。笔者整理绘制了一张我国历年育成的李品种系谱图,发现目前我国选育的李品种中,多数亲本是具有我国地域特点的地方优良品种,且直接或间接来自少数几个亲本。‘福摩萨’‘六号李’‘绥棱红’和‘绥李3号’是骨干亲本,在我国李鲜食和随后的观赏品种选育中发挥了一定的作用,同时也反映出我国育成的品种之间亲缘关系近,存在亲本选择有局限、遗传基础较狭窄的突出问题。除此之外,我国李育种还存在重要性状遗传规律研究缺乏、砧木育种进展缓慢、抗病育种尤其抗李痘病育种意识淡薄等问题。综上所述,笔者旨在对我国李育种的进展、成果和存在问题进行梳理,并提出相应的建议,以资借鉴。  相似文献   

18.
我国榛属植物种质资源的研究、利用与创新   总被引:3,自引:0,他引:3  
榛子为榛科榛属植物,全世界有16种,我国原产8个种和2个变种;我国现有榛林的95%是野生平榛,选育的平欧杂种榛和引进的欧洲榛是目前主要的栽培种。从平榛资源调查和选优、平欧杂种榛种质创新和品种选育、我国其他榛属资源的利用和国外榛属资源的引种等方面对我国榛子的育种现状进行了介绍;对我国及国外榛属植物种质资源的研究进展进行了总结,对比了我国与世界先进水平的差距;并从现有平欧杂种榛在科研和生产中亟待解决的问题、第1代平欧杂种榛的目标性状改良及今后榛属植物的育种策略等方面,对榛属育种与资源利用提出了一些见解,以期与国内同行专家进行交流。  相似文献   

19.
20世纪60年代新西兰的Don Mc Kenzie博士从果农J.H.Kidd配置的杂交后代中选出了世界级的苹果品种‘嘎拉’。随后,新西兰植物与食品研究所于80年代初期开始了持续专业的苹果育种研究,先后培育出了一系列优良的世界性品种。苹果育种技术也从常规育种进入了分子育种时代,一跃成为世界苹果育种强国,吸引了世界众多果树科研单位和育种者争相学习其先进技术和科研成果。为了进一步提升中国苹果育种水平,缩小与苹果育种强国的差距,作者系统的介绍了新西兰的苹果品种和砧木选育的发展历程、选育方法,特别是生物技术在新品种选育中的应用,并对比分析目前中国苹果品种及砧木选育的方法,提出中国苹果育种方法的改进建议,希望对中国的苹果育种工作有所启发。  相似文献   

20.
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