权衡城市扩张、耕地保护与生态效益的京津冀城市群土地利用优化配置情景分析

京津冀城市群作为影响我国经济发展的重要区域,具有多重战略意义。然而,快速的城市扩张在提高社会、经济水平的同时,伴随着资源供求矛盾加深、耕地被侵占、生态退化,以及水、大气环境污染等众多突出问题,如何优化调整城市空间结构与布局,实现社会、经济发展与生态环境保护等多目标的协同优化是京津冀规划管理与决策的关键。从土地覆盖/利用数量和空间布局两个重点方面出发,通过多目标优化模型和CLUE-S模型的构建,提出了多目标权衡下的土地扩张优化情景预案,以期为京津冀城市群扩张布局与土地利用优化配置规划与管理提供科学参考。结果表明:一方面,利用多目标遗传算法(MOGA)可以很好地实现对京津冀土地利用结构优化配置及其与社会、经济及生态效益等多目标的定量化求解,为决策人提供满足不同权衡目标的多种选择,并通过与CLUE-S模型相结合,实现京津冀城市群土地利用格局的空间优化配置情景模拟;另一方面,研究结果表明,综合考虑了社会、经济和生态效益的优化方案中,林地的增加可以相对满足政策要求,增幅较大,耕地较未优化方案减幅放缓,符合耕地保有量的要求,同时,也从空间上减少了对重要生态用地的侵占。本研究的方法与结果可为京津冀城市群土地利用规划与生态安全格局建设提供理论与应用参考。     

基于地统计学的黄土高寒区典型林地土壤水分盈亏状况研究

土壤水分是黄土高寒区水循环、地下水补给和植被恢复的关键因素,基于地统计学研究土壤水分空间分布及其盈亏状况,揭示林地土壤水分的空间分布规律、变异特征及空间结构,对于区域植被恢复具有重要价值。以大通县安门滩小流域人工林地作为研究对象,运用地统计学方法对其5月、7月和9月的土壤储水量、林地耗水量和土壤水分盈亏量进行综合分析。研究结果表明:(1)土壤储水量总体表现为9月5月7月,而林地耗水量为7月9月5月,5—7月绝大多数林地的土壤水分呈亏损状态,而7—9月所有林地土壤水分都得到了补充,总体来看,5—9月研究区多数林地的土壤水分有所盈余,土壤储水量、林地耗水量和土壤水分盈亏量均采用指数模型作为最优理论变异函数模型;(2)5月、7月和9月土壤储水量呈南高北低、西高东低的空间分异规律,且西南-东北方向变异较东南-西北方向剧烈;各月林地耗水量在西南-东北方向变异较东南-西北方向剧烈,总体表现为西南部区域低于东北部区域;在5—7月、7—9月和5—9月这三个时期内,土壤水分盈亏量的取值均呈现出东北部区域小于西南部区域的特点。综上,当地土壤水分状况与林地耗水量分布格局并不完全匹配,虽然绝大部分林分能够维持土壤水分收支平衡,但部分山脚处的青杨林地和中部区域的华北落叶松林地出现了土壤水分亏损的现象。为防止林地水分环境恶化,在之后黄土高寒区的植被建设过程中,应适当调整林分配置。     

Climate change disrupts core habitats of marine species

Driven by climate change, marine biodiversity is undergoing a phase of rapid change that has proven to be even faster than changes observed in terrestrial ecosystems. Understanding how these changes in species composition will affect future marine life is crucial for conservation management, especially due to increasing demands for marine natural resources. Here, we analyse predictions of a multiparameter habitat suitability model covering the global projected ranges of >33,500 marine species from climate model projections under three CO₂ emission scenarios (RCP2.6, RCP4.5, RCP8.5) up to the year 2100. Our results show that the core habitat area will decline for many species, resulting in a net loss of 50% of the core habitat area for almost half of all marine species in 2100 under the high-emission scenario RCP8.5. As an additional consequence of the continuing distributional reorganization of marine life, gaps around the equator will appear for 8% (RCP2.6), 24% (RCP4.5), and 88% (RCP8.5) of marine species with cross-equatorial ranges. For many more species, continuous distributional ranges will be disrupted, thus reducing effective population size. In addition, high invasion rates in higher latitudes and polar regions will lead to substantial changes in the ecosystem and food web structure, particularly regarding the introduction of new predators. Overall, our study highlights that the degree of spatial and structural reorganization of marine life with ensued consequences for ecosystem functionality and conservation efforts will critically depend on the realized greenhouse gas emission pathway.     

Data-driven estimation of nitric oxide emissions from global soils based on dominant vegetation covers

Soils are a major source of global nitric oxide (NO) emissions. However, estimates of soil NO emissions have large uncertainties due to limited observations and multifactorial impacts. Here, we mapped global soil NO emissions, integrating 1356 in-situ NO observations from globally distributed sites with high-resolution climate, soil, and management practice data. We then calculated global and national total NO budgets and revealed the contributions of cropland, grassland, and forest to global soil NO emissions at the national level. The results showed that soil NO emissions were explained mainly by N input, water input and soil pH. Total above-soil NO emissions of the three vegetation cover types were 9.4 Tg N year⁻¹ in 2014, including 5.9 Tg N year⁻¹ (1.04, 95% confidence interval [95% CI]: 0.09–1.99 kg N ha⁻¹ year⁻¹) emitted from forest, 1.7 Tg N year⁻¹ (0.68, 95% CI: 0.10–1.26 kg N ha⁻¹ year⁻¹) from grassland, and 1.8 Tg N year⁻¹ (0.98, 95% CI: 0.42–1.53 kg N ha⁻¹ year⁻¹) from cropland. Soil NO emissions in approximately 57% of 213 countries surveyed were dominated by forests. Our results provide updated inventories of global and national soil NO emissions based on robust data-driven models. These estimates are critical to guiding the mitigation of soil NO emissions and can be used in combination with biogeochemical models.     

Predator response to the coloured eyespots and defensive posture of Colombian four-eyed frogs

Deimatic displays, where sudden changes in prey appearance elicit aversive predator reactions, have been suggested to occur in many taxa. These (often only putative) displays frequently involve different components that may also serve antipredator functions via other mechanisms (e.g., mimicry, warning signalling, body inflation). The Colombian four-eyed frog, Pleurodema brachyops, has been suggested to gain protection against predation through putative deimatic displays where they inflate and elevate the posterior part of their body revealing eye-like colour markings. We exposed stationary artificial frogs to wild predators to test whether the two components (eyespot/colour markings, defensive posture) of their putative deimatic display, and their combination, provide protection from predation without the sudden change in appearance. We did not detect any obvious additive effect of defensive posture and eyespots/colour markings on predation risk, but found a marginally significant trend for model frogs in the resting posture to be less attacked when displaying eyespots/colour markings than when they were not, suggesting that the presence of colour markings/eyespots may provide some protection on its own. Additionally, we found that models in a resting posture were overall more frequently attacked on the head than models in a defensive posture, indicating that a defensive posture alone could help redirect predator attacks to non-vital parts of the body. The trends found in our study suggest that the different components of P. brachyops' coloration may serve different functions during a deimatic display, but further research is needed to elucidate the role of each component when accompanied by sudden prey movement.     

微生物相互作用中的空间自组织

微生物在全球生态系统中占据着重要地位, 其中一个重要的研究领域是微生物与环境(包括无机环境与生物环境)之间的相互作用。在生态相互作用过程中, 微生物常常通过自组织形成特定的空间模式。微生物的空间模式在种群稳定性、群落动态变化以及维持合作行为方面具有重要作用。本文中, 我们梳理了当下对微生物空间自组织及其所形成的空间模式的研究内容, 首先介绍什么是空间自组织, 再根据生态相互作用类型对自组织的空间模式进行描述, 其中重点讨论合作与竞争中的空间模式, 接着关注微生物空间自组织的过程, 最后我们指出空间自组织对整个群体的结构和功能稳定具有重要意义。研究微生物种群间相互作用中的空间模式, 有助于探索维持合作行为的新机制, 进而为微生物共生系统的构建提供新的理解。     

Effects of forest loss and fragmentation on pollen diets and provision mass of the mason bee,Osmia cornifrons,in central Japan

1. Habitat loss and fragmentation potentially affect the performance of bees that forage nectar and pollen of plants in their habitats. In forest landscapes, silvicultural conifer plantations often have reduced and fragmented natural broadleaf forests, which seem to provide more floral resources for bees than do the plantations. 2. This study evaluated the effects of forest characteristics (i.e. elevation, area, edge length, and tree size of natural forests) on pollen diets (plant taxa assemblages of pollen grains in provisions) and total provision mass in oviposited chambers in nests made by a standardised number of Osmia cornifrons bees at 14 sites in a forestry area in central Japan. 3. From April to May, the numbers of nests and chambers per nest increased, and the provision mass per chamber decreased. Main pollen sources were Prunus at higher elevations in April and Wisteria at lower elevations in May, foraging on which increased the numbers of nests and chambers per nest. The provision mass per chamber was smaller at higher elevations in more fragmented natural forests. Decreases in the area of natural forests within the foraging range (400‐m radii) of O. cornifrons increased the utilisation of Rubus pollen and decreased the total provision mass. 4. These findings suggest that the loss and fragmentation of natural broadleaf forests change pollen diets and reduce the provision mass of mason bees, which may reduce the number and size of their offspring.     

In Search of a Consistent Solution to Allocation of Joint Production

Three consistency problems are identified that arise when partitioning a product system with joint production according to an allocation key, such as revenue or mass of the joint products, namely: lacking consistency of rationales and procedures; lacking consistency of monetary, mass, and energy balances in the partitioned product systems; and lacking consistency of results across model resolution and classification of the intermediate flows. Different solutions to these consistency problems are described, including the attempt of ecoinvent to solve the third consistency problem with a system model that uses revenue allocation at the point of substitution. The problems with the different practical implementations are described. For each of the three consistency problems, a solution is proposed and combined into a single consistent solution. The consistency of rationales and procedures is ensured by asking only one question at a time and performing a separate allocation and calculation for each question. The problem of maintaining monetary, mass, and energy balances is solved by a generalized allocation correction. The identified problem with consistency of results across model resolution and classification is solved by redefining the point of substitution. It is described what consequences the solutions will have if their results are misused for decision making that will shift demand between products.     

Game theory-based stakeholder analysis of marine nature reserves and its case studies in Guangdong Province,China

Marine nature reserves (MNRs) play an important role in biodiversity conservation and ecosystem restoration, which are valuable for marine resource protection in China. Many stakeholders are involved in MNRs. The interactions between MNR managers and other stakeholders affect the effectiveness of MNR management. This work divided MNR stakeholders into three categories and applied the analytical hierarchy process (AHP) to identify the key stakeholders. The game model was set up to analyze the strategies of MNR staff and stakeholders. The situation of key stakeholders and management was studied in two MNRs in Guangdong Province through field research and questionnaires. The results showed that fishermen were the main stakeholders in the two cases. The strategies adopted by MNR staff to improve the efficiency of law enforcement and decrease the probability of illegal activities of fishermen are to increase penalties, improve the arrest rate of illegal activities, and reduce the cost of law enforcement per patrol. We suggested that the fishermen’s negative impacts could be minimized by establishing a market management system to reduce illegal earnings, a record-keeping system to share additional benefits only with the fishermen who comply with the law, and an association mechanism in the coastal province to control illegal fishing across provincial boundaries. Identifying key stakeholders and analyzing their relationships could be helpful to find out the best strategy for different MNRs. Building a community of shared interests among various stakeholders could be a promising way to resolve conflicts and improve management effectiveness in MNRs.     

青藏高原栽培大麦千粒重空间分布格局及其与环境因子的关系

千粒重是大麦产量的重要构成因素之一。青藏高原强辐射、低温、干旱的生态环境孕育了现代农业所急需的大麦种质资源,但是迄今为止尚未见到有关青藏高原栽培大麦WTS与环境因子关系的系统性研究报道。为了揭示青藏高原栽培大麦千粒重的空间分布规律,探明不同环境因子对青藏高原栽培大麦千粒重(WTS)积累的影响程度,利用83个样点的地理、气候、土壤因子数据,研究了青藏高原栽培大麦WTS的分布特征。结果表明:(1)在地理水平方向上,青藏高原栽培大麦WTS总体呈现出斑块状交错分布的格局,形成了以西藏曲水、堆龙德庆、白朗、乃东、日喀则、扎囊、贡嘎、加查、达孜、谢通门、拉孜、定日为中心的青藏高原西南部和青海海晏、门源、刚察为中心的青藏高原东北部等2个栽培大麦WTS高值区;(2)在地理垂直方向上,栽培大麦WTS的变化呈现出"N"型分布格局,即在海拔3600.0—3900.0m和4500.0m以上形成2个WTS高值区,这2个海拔区间栽培大麦WTS分别为(49.6815±10.0764)g和(47.9500±0.1732)g;(3)影响栽培大麦WTS的环境因子从大到小的顺序是抽穗-成熟期降水量土壤速效钾含量分蘖-拔节期日照时数抽穗-成熟其平均气温抽穗-成熟期日照时数拔节-抽穗平均气温日较差地理经度。