陕北地区土地利用及景观格局变化对生态服务价值的影响*——基于退耕还林（草）背景

［目的］通过揭示退耕还林（草）工程背景下陕北地区近25年生态系统服务价值的演变规律，旨在为陕北地区的土地利用规划及新一轮退耕还林（草）政策的推进提供参考。［方法］以生态环境脆弱的陕北地区为研究对象，基于1990年、2000年、2015年3期的土地利用变化数据，以退耕还林（草）政策的实施为节点，利用土地转移矩阵、景观格局指数、生态服务价值损益表等方法对陕北地区的土地利用情况、景观格局演变以及生态服务价值的变化进行分析，借助相关性系数对土地利用类型、景观格局及生态服务价值之间的关系进行了定量研究。［结果］（1）草地、耕地和林地是陕北地区最主要的土地利用类型，耕地面积减少，林草地面积持续增加且增速加快。（2）近25年，陕北地区景观格局的连接性和通达性降低，景观格局主要呈破碎化发展趋势。研究区各景观类型的破碎化程度增大，空间异质性增加，草地是该地区的优势景观类型。（3）陕北地区1990年、2000年和2015年各类生态系统提供的总生态服务价值分别为38919亿元、39431亿元和40622亿元，退耕还林（草）前年均增长率为1396%，退耕还林（草）后这一比率增加至5622%。［结论］受退耕还林（草）政策的影响，陕北地区土地利用类型和土地景观格局的变化均对生态系统服务价值有显著的影响，但是不同的景观指数对生态系统服务价值的影响程度和趋势不同，水域和林草地面积对生态系统服务价值呈正相关，未利用地和城乡建设用地面积对生态系统服务价值呈负相关。     

Quantifying and understanding land cover changes by large and small oil palm expansion regimes in the Peruvian Amazon

With rapid increases in global food demand and production, oil palm expansion constitutes a major emerging challenge for forest conservation in Amazonia and other tropical forest regions. This threat is evident in the Peruvian Amazon, where local and national incentives for oil palm cultivation along with growing large-scale investments translate into accelerated oil palm expansion. Environmental sustainability of oil palm cultivation in the Peruvian Amazon is contingent on policy incentives for expansion onto already-cleared lands instead of biodiverse, high carbon primary rainforests. Previous research indicates that while industrial plantations use less land area than local smallholders, companies have a higher tendency to expand into primary rainforests. However, the motivations behind these differing expansion scenarios remain unclear. In this study we combine data from optical and radar satellite sensors with training information, field discussions, and review of public documents to examine the policy incentives and spatial patterns associated with oil palm expansion by smallholders and industries in one of Peru’s most rapidly changing Amazonian landscapes: the Ucayali region of the city of Pucallpa. Based on our satellite-based land cover change analysis, we found that between 2010 and 2016, smallholders utilized 21,070 ha more land area for oil palm than industries but industrial expansion occurred predominantly in old growth forests (70%) in contrast to degraded lands for smallholders (56%). Our analysis of national policies related to oil palm expansion reveal policy loopholes associated with Peru’s “best land use” classification system that allow for standing forests to undergo large-scale agricultural development with little government oversight. We conclude that both sectors will need careful, real-time monitoring and government engagement to reduce old-growth forest loss and develop successful strategies for mitigating future environmental impacts of oil palm expansion.     

共享单车预付押金的法律性质及其法律规制

共享单车预付押金收取模式的异变和返还期限的错配与分离，颠覆了“一物一押”的传统押金结构，异变为“一人一押、一物多押”“一辆单车、多份押金”的新型结构，并使共享单车预付押金朝金融化衍变而呈现出类金融色彩。在免押模式尚不足以全面施行的条件下，应采取特殊的规制方法，通过规范押金收取协议，对预付押金进行账户隔离和妥善保管，增强押金收取、存管和退还的信息透明度，合理利用押金孳息建立行业风险基金以及统一监管机构，有效保护共享经济预付押金的财产安全。     

New perspectives on farm size and productivity

The farm size and productivity debate has been limited by the focus on land or labor productivity, generally showing respective productivity advantages to smaller or larger sized farms. Our purpose is to provide new perspectives on the debate by bringing together evidence from a set of novel case studies in both rich and poor countries. Common to them are the adoption of total factor productivity (TFP) as the comparative performance measure, and the reliance on panels of farm micro data. The present article presents a synthesis of findings from five case studies in (i) Malawi, Tanzania, and Uganda; (ii) Bangladesh; (iii) Brazil; (iv) Australia; and (v) the United States. The preponderance of evidence from these studies suggests that there is no single economically optimal agrarian structure; rather, it appears to evolve with the stage of economic development. Certain farm sizes face relative productivity advantages, such as small farms in Africa. But with economic and market growth, that smallholder advantage will likely attenuate, moving toward constant and eventually increasing returns to size. Yet, importantly, small farms may be quite dynamic, and need not be a drag on agricultural growth until perhaps well into the development process.     

Rural development and the role of game farming in the Eastern Cape,South Africa

The analysis of game farming is set in the Eastern Cape, South Africa. Game farming reorders the use, meaning and value of land and animal species. However, what it means for rural development processes in the immediate region and beyond is not well accounted for. We perceive game farming as an assemblage that brings together new actors, new forms of land use and new discourses. We argue that although game farming has generated new opportunities and new forms of added value to the available resources (e.g. eco-tourism, trophy hunting, game-meat production), situated in the history and contemporary context of the Eastern Cape, it is a contested, and from a development point of view, problematic land-use practice. We argue that game farming constrains land and agrarian reforms: the distribution of land and income remains skewed; ‘poaching’ occurs and game farms do not, or only minimally, generate new and badly needed employment opportunities. The game farm has emerged as an exclusive, globally well-connected space. The nature of the relationships this space maintains with the surrounding communities is, however, such that the overall contribution to rural development in South Africa is questionable.     

“Been-heres vs. come-heres” and other identities and ideologies along the rural–urban interface: A comparative case study in Calaveras County,California

The rural–urban interface is the place of transition between that which we call “urban” and that which we call “rural.” The interface is situated between two places perceived to be different, but which are indelibly linked. Although the functional differences between “rural” and “urban” people (or those seen as “been-heres” versus “come-heres”) seem to be diminishing, differing perspectives and preferences persist along the rural–urban edge. Such differences influence the way that land users, decision makers, and the community manage the environment and react to landscape change. Using a comparative case study in Calaveras County, California, I examine the differences and similarities between “been-heres” and “come-heres” along several lines: basic demographic characteristics, political party affiliations and ideologies, and conceptions of private property rights, concluding that the dichotomy is false but instructive. The been-here/come-here divide, rather than being a definitive means for characterizing stakeholders or predicting their behavior or perspectives, serves as a heuristic for understanding the starting places of certain actors. Furthermore, this kind of analysis reveals not only where and how people and perspectives contrast but also the ways that they converge. Improving our understandings differing people and perspectives is especially important as decision-makers struggle to plan for and manage livable places and sustainable environments among groups with varying preferences which may sometimes conflict.     

Lineage and land reforms in Malawi: Do matrilineal and patrilineal landholding systems represent a problem for land reforms in Malawi?

Based on government statistics and interviews with villagers across Malawi this article argues that customary matrilineal and patrilineal land tenure systems serve to weaken security of land tenure for some family members as well as obstructing the creation of gender-neutral inheritance of lands. Data from the National Census of Agriculture and Livestock 2007and the 2008 Population and Housing Census are used to characterize marriage systems and landholding patterns of local communities. Marriage systems correspond to customary land-tenure patterns of matrilineal or patrilineal cultures. The differences between the two ways of land holding represent a challenge for land reforms aimed at unifying rules for land tenure and land devolution. Drawing on an analogy of the resilience of the patrilineal land holding system in Norway, we argue that it will be difficult to remove the preferential rights of lineage members directly. We recommend that, instead of creating a unified national system, existing land rights should be formally recognized and circumscribed by fair procedures. A well-designed landholding system should aim to ease the transitions of diverse customary tenure systems towards the requirements of a modern large-scale society.     

Socioeconomic determinants of farmland value in India

Developing countries have achieved remarkable overall economic diversification and growth during the last few decades, but farmland has remained a prime pillar of the livelihood support system of resource poor people in the rural areas of these countries. For these people, land is still the most important resource as it has multiple utilities such as a symbol of social standing, collateral value and a reserve capital asset for emergencies. Agricultural land assumes different values for different owners. This study establishes the criticality of age, education level, size of family workforce, dependency on agricultural income, productivity of land and location of farmland in influencing perception of value of farmland. Ignoring these factors creates a gap in the value of farmland as perceived by the farmland owner and the government. Knowledge of these factors may help in making appropriate adjustments in government declared prices of farmland for determining appropriate land compensation rate for a specific location.     

Assessing High-Speed Rail’s impacts on land cover change in large urban areas based on spatial mixed logit methods: a case study of Madrid Atocha railway station from 1990 to 2006

This paper proposes an accessibility-based spatial mixed logit (SML) model with panel data structure to examine the impacts of High-Speed Rail (HSR) on land cover change in large urban areas. Using data between 1990 and 2006, impacts of the Spanish HSR on Madrid’s Atocha railway station influence area – a 20 km radius buffer centred on the station – were investigated. To model the HSR impacts, besides socioeconomic variables, the development of both local and regional transportation networks with corresponding accessibility improvement is also taken into account to segregate the impacts of land-cover change brought by different sources of accessibility measures. In this study, two SML models are used: one incorporates regional accessibility indicators as a base model, and the other does not, acting as a control model. The model estimation results reveal that the reduction of the local and regional weighted travel average time has positive impacts on the Atocha station catchment area’s urbanised land-cover rates. Although the base and control models both achieve high goodness-of-fit values, the base model that considers regional accessibility reveals a better goodness-of-fit statistic and is more robust than the control model. It is concluded that the improvement of regional accessibility due to the arrival of HSR at Atocha station plays an essential role in the urbanisation of land cover changes in the study area.     

Taming Airbnb: Toward guiding principles for local regulation of urban vacation rentals based on empirical results from five US cities

Urban vacation rentals, a phenomenon that has grown explosively very recently, bring benefits to cities but also impose quality of life and housing market impacts on neighborhoods. As a consequence, cities are beginning to grapple with creating regulatory regimes for managing this new land use and its encroachments on residential areas. This article uses webscraped data from Airbnb, the industry leader, to analyze the geographical patterns and concentrations of these impacts in five US cities: Austin, Boston, Chicago, San Francisco, and Washington, DC. It uses the findings to put forth four general principles for cities seeking to manage impacts imposed by Airbnb and its competitors. These are that webscraping is an imperfect but relatively cheap and effective means of gathering locally specific data; that “spiky” usage patterns dictate a microgeographic approach to regulation; that meaningful regulation necessitates dedicated enforcement, likely paid for with permit fees; and that it is desirable to distinguish between “mom-and-pop” hosts and those operating at a commercial scale.