Ten facts about land systems for sustainability.

Land use is central to addressing sustainability issues, including biodiversity conservation, climate change, food security, poverty alleviation, and sustainable energy. In this paper, we synthesize knowledge accumulated in land system science, the integrated study of terrestrial social-ecological systems, into 10 hard truths that have strong, general, empirical support. These facts help to explain the challenges of achieving sustainability in land use and thus also point toward solutions. The 10 facts are as follows: 1) Meanings and values of land are socially constructed and contested; 2) land systems exhibit complex behaviors with abrupt, hard-to-predict changes; 3) irreversible changes and path dependence are common features of land systems; 4) some land uses have a small footprint but very large impacts; 5) drivers and impacts of land-use change are globally interconnected and spill over to distant locations; 6) humanity lives on a used planet where all land provides benefits to societies; 7) land-use change usually entails trade-offs between different benefits-"win-wins" are thus rare; 8) land tenure and land-use claims are often unclear, overlapping, and contested; 9) the benefits and burdens from land are unequally distributed; and 10) land users have multiple, sometimes conflicting, ideas of what social and environmental justice entails. The facts have implications for governance, but do not provide fixed answers. Instead they constitute a set of core principles which can guide scientists, policy makers, and practitioners toward meeting sustainability challenges in land use.

Differentiation and concordance in smallholder land use strategies in southern Mexico's conservation frontier.

Forest cover transitions in the developing tropics are conditioned by agricultural change. The expansion, intensification, and diversification of agricultural land uses are tied to regional economic/environmental regimes and decisions of local farming households. Land change science and agrarian systems research share an interest in the drivers of household strategies, land use impacts, and typologies of those land uses/drivers. This study derives a typology of farming households in southern Mexico based on emergent patterns in their land use combinations and analyzes their household and policy drivers. The results reveal broadly diversified household land use portfolios as well as three emergent clusters of farmstead production orientation: (i) extensive subsistence-oriented conservationists, (ii), dual extensive-intensive farmers, and (iii) nonextensive diversified land users. Household membership in these clusters is uneven and strongly related to tenancy, land endowments, wage labor, and policy subsidies. Although most households are following a nonextensive agricultural strategy incorporating off-farm incomes, the likelihood of a regional forest transition remains debatable because of the disproportionate deforestation impacts of the less common strategies. Conservation development policies in the region need to accommodate diverse smallholder farming rationales, increase off-farm opportunities, and target sustainable development with the assistance of community conservation leaders.