The paper reveals that ever since the 1950s, after the first land reform of distributing landownership (or possession under public ownership) to small farmers, the irrational and polyopolisticland use by able-bodied part-time and absent small farmers earning higher off-farm income butunwilling to lease the under-producing land beyond their family consumption need to full-timefarmers, has been a global obstacle with both public and private land ownership, traditional andmodern agriculture, fragmented small and consolidatorily enlarged land, low and high incomeeconomies, food under-self-suffi
We used the process-oriented niche model CLIMEX to estimate the potential global distribution of serrated tussock under projected future climates. Serrated tussock is a drought-tolerant, wind- and human-dispersed grass of South American origin that has invaded pastures in Australia, Europe, New Zealand, and South Africa. The likely effect of climate change on its potential global distribution was assessed by applying six climate-change scenarios to a previously developed model.
AIM: The geographical expansion of white‐winged doves (Zenaida asiatica) in North America has attracted the attention of biologists and sportsmen because of their recreational and aesthetic value; however, data on factors driving the spatial spread of this species are lacking. We examined spatial and temporal patterns of range expansion for white‐winged doves along the northern edge of their geographical range from 1979 to 2007 and used a dynamic occupancy model to estimate when and where doves would be found along an expansion gradient. LOCATION: Southern half of the USA.
The most important land and water issues facing North America and the world â including landâuse patterns, water management, biodiversity protection, and climate adaptation â require innovative governance arrangements. Most of these issues need to be addressed at several scales simultaneously, ranging from local to global. They require action at the scale of large landscapes given that the geographic scope of the issues often transcends the legal and geographic reach of existing jurisdictions and institutions.
Wetland stopover use by migratory shorebirds is concurrently influenced by habitat characteristics within a stopover site and characteristics related to the broader context surrounding the stopover site. To conserve wetland habitats essential for shorebird migration through the interior of North America, we need to understand how these dual scales influence stopover use.
Fire, climatic variability, and grazing by large herbivores have historically limited woody vegetation in the tallgrass prairie region of North America to gallery forests in protected areas along rivers and streams. Fire, in particular, has been a strong selective pressure against woody vegetation. Consequently, we expect that dominant tree species in these forests have developed mechanisms for tolerating periodic surface fires.
Over fifteen years have elapsed since the transition from the centrally plannedeconomic system started in the early 1990’s. During this time agricultural andrural areas of Central and Eastern Europe have undergone profound structuralchanges with wide variations in the degree of transformation and in the rate ofsuccess in creating a competitive market and private ownership based food andagricultural system. By becoming member of the European Union the "transition"in its traditional interpretation has been concluded in ten of the Central EastEuropean countries.
Many deer populations in Europe and North America have increased in abundance over the last decades. The increasing populations potentially entail both ecological and economic challenges and opportunities, but in practice we still know little about the extent to which these opportunities are being exploited in different management systems. The Norwegian red deer population has increased in density and expanded rapidly since the 1950s. Traditionally, red deer hunting has been undertaken by the local landowner and his relatives and friends.
Public land management across North America now incorporates multiple ecological and social values and has led to use of increasingly complex silvicultural systems, such as those designed to emulate natural disturbance regimes, in an effort to manage for this wider variety of objectives. In the eastern United States and Canada, canopy gap-based silvicultural systems are often used to promote and sustain intra-stand variability in temporal and spatial patterns.
The land surface phenology (LSP) start of season (SOS) metric signals the seasonal onset of vegetation activity, including canopy growth and associated increases in land-atmosphere water, energy and carbon (CO₂) exchanges influencing weather and climate variability. The vegetation optical depth (VOD) parameter determined from satellite passive microwave remote sensing provides for global LSP monitoring that is sensitive to changes in vegetation canopy water content and biomass, and insensitive to atmosphere and solar illumination constraints.