Baja California peninsula oases: An agro-biodiversity of isolation and integration

Agro-biodiversity in the desert oases of the Baja California peninsula, Mexico is a product of isolation and integration events through time and across peninsular spaces. Historic inventories of agricultural introductions provide a baseline from which to measure Mission-era crop persistence or genetic erosion in fifteen missions established during the Jesuit occupation (1697–1768). These mission-oases function as a network of interconnected sites supporting cultivated plant assemblages isolated from one another and the Mexican mainland by a desert matrix, by limited transportation infrastructure on the peninsula, and the surrounding sea. Garden surveys of perennial crop species and farmer interviews reveal that oases serve as refugia of Mission-era crop species and traditional knowledge. Isolation-connectivity analyses indicate that this agro-biodiversity disappears at the extremes: The most isolated and the fully integrated oases are unable to support heritage perennial crop species and traditional farming systems over long time scales. We describe how phases and processes of isolation and connectivity transform agro-biodiversity composition in this archipelago of peninsula oases and explore policy applications that could preserve this critical diversity and the rare and available oasis communities.     

Date palm as a keystone species in Baja California peninsula,Mexico oases

Based on historical records, Jesuit missionaries were the first to introduce date palm (Phoenix dactylifera L., Arecacea) to the mission oases of the Mexican Baja California peninsula. Seedling date palms readily naturalized and have partially, and in some cases almost entirely replaced the native fan palm, Washingtonia filifera and Washingtonia robusta in the oases. These wild and introduced palms form the over-story for smaller cultivated trees, shrubs, and open gardens of mixed perennial and annual cultivars in complex agro-ecosystems. They also grow in dense stands along the oases arroyos where they may be “owned” by various oasis residents and semi- to carefully managed, or comprise wild populations beyond the periphery of the oasis settlements. These palms serve as ecological and cultural keystone species, altering oasis microclimates and providing shade for understory crops, shelter and food resources for resident and migratory fauna, and building materials and food for oasis human residents. I explore the agro-ecological role of the date palm in Baja California peninsula oases.     

'A good site for health': Missionaries and the pathological geography of central southern Africa

Throughout much of the late eighteenth and early nineteenth centuries, the tropics and subtropics were constructed as a relatively homogenous realm. The supposed 'pathological potency' of these regions was assumed to render them particularly hazardous for European constitutions relative to 'temperate' locations. The interior of Africa represented one such apparently pestilential place. This paper examines how the experiences of nineteenth-century missionaries based at various stations in central southern Africa might have been influenced by popular and scientific debates focusing on environment, climate and health in Africa. We also illustrate how their perspectives may have challenged popular homogenized conceptualizations of interior Africa as a uniformly dangerous place for Europeans and helped to identify a spatially varied pathological geography of the region.     

西方制图技术的传入对中国近代制图技术的影响

16世纪末,西方制图技术传入中国,相对独立发展的中国传统地图学,开始受到西方的影响。直到民国的3个多世纪内,西方包含经纬度控制和投影变换等的精确制图技术,在每个阶段传入和传播的过程中,对中国传统地图学的发展均产生了不同程度的影响。本文以明末、清初、清末至民国时期作为研究的主要时段,着重分析了每个时期西方制图技术的传入背景、受其影响产生的地图作品,对中国传统地图学的影响,并梳理中国传统地图学在西方制图技术的影响下,由独立发展到对西方制图技术的抵触和借鉴直至吸收,到完成中国地图学由传统旧法向现代新法的转变,构建起符合中国社会发展需求的近代制图理论的过程,以期能对现代的地图制图产生相应的启发。