Assessing factors influencing phosphorus (P) availability in soils is important in preventing its overexploitation and excessive application in agricultural systems. Despite high historical P applications in the federal state of Brandenburg (Germany), county data on soil test P (STP) reveal considerable disparities in soil available P. In addition, negative soil balances as a result of small mineral P and manure inputs have been observed, raising questions about the factors leading to this situation.

The introduction to this set of papers highlights four challenges to the large-scale analysis of population growth at protected area edges in Africa and Latin America undertaken by George Wittemyer and colleagues in their 2008 paper published in Science. First, it raises questions about their sampling procedures, given national-level variation in systems of protected area designation and protected area estates. Second, it challenges the largely economic model of migration decisions that underlies their analysis.

Ethiopia experiences a fierce political debate about the appropriate land tenure policy. After the fall of the socialist derg regime in 1991, land property rights have remained vested in the state and only usufruct rights have been alienated to farmers – to the disappointment of international donor agencies. This has nurtured an antagonistic debate between advocates of the privatization of land property rights to individual plot holders and those supporting the government’s position. This debate, however, fails to account for the diversity and continuities in Ethiopian land tenure systems.

Land-use and cover changes around Budongo Forest Reserve (BFR) were analysed from multi-temporal LandSat images (1988 and 2002) and associated field-based studies in 2003-2004. Three major land-use and cover classes: forest/woodland, sugarcane plantations and grassland/shifting-cultivation/settlements were clearly discriminated. The area under sugarcane cultivation increased over 17-fold, from 690 ha in 1988 to 12729 ha in 2002, with a concomitant loss of about 4680 ha (8·2 per cent) of forest/woodland, mainly on the southern boundary of BFR.

A number of international donors, national governments and project proponents have begun to lay the groundwork for REDD+, but tenure insecurity – including the potential risks of land grabbing by outsiders and loss of local user rights to forests and forest land – is one of the main reasons that many indigenous and other local peoples have publicly opposed it. Under what conditions is REDD+ a threat to local rights, and under what conditions does it present an opportunity?

There is an ongoing debate on the effect different property regimes have on the use of natural resources and land conversion (i.e., deforestation or reforestation). Much of the discussion has been centered on the two main forms of tenure regime: common-pool system and private property. Case studies around the world have provided evidence on whether one is more effective at preventing deforestation than the other, but there is not a clear pattern. Part of the problem is that evidence comes from theoretical models or isolated case studies instead of comparative studies across large areas.