The results of the Forest Resources Assessment 2000 carried out by FAO are synthetically presented and discussed. The world forest coverage is estimated equal to 38.6 million km 2 . The comparison of the estimates from the period 1990-2000 with those from the period 1980-1990 points out a certain general deceleration of the rate of net deforestation, that currently involves around 9 million hectares every year. However, the annua1 loss of tropical forests is still very large, while temperate and borea1 forests are in expansion. Overall, FRA2000 produced a relevant effort to compensate the existing technical, institutional and financial constraints and shortcomings for monitoring the world forest resources. The need to increase the quality and the frequency of forest surveys, both at national and international levels, s t a stands as a major issue to cope with.

http://ojs.aisf.it/index.php/ifm/article/download/774/738

Valutazione delle risorse forestali a livello globale

The ‘novel ecosystem' concept has captured the attention of scientists, managers, and science journalists, and more recently of policymakers, before it has been subjected to the scrutiny and empirical validation inherent to science. Lack of rigorous scrutiny can lead to undesirable outcomes in ecosystem management, environmental law, and policy. Contrary to the contentions of its proponents, no explicit, irreversible ecological thresholds allow distinctions between ‘novel ecosystems' and ‘hybrid' or ‘historic' ones. Further, there is no clear message as to what practitioners should do with a ‘novel ecosystem'. In addition, ecosystems of many types are being conserved, or restored to trajectories within historical ranges of variation, despite severe degradation that could have led to their being pronounced ‘novel'.

/pdf/a-critique-of-the-novel-ecosystem-concept-2dwb6tb0zc.pdf

A critique of the ‘novel ecosystem’ concept

Land use and land cover change (LUCC) affects regional climate through modifications in the water balance and energy budget. These impacts are frequently expressed by: changes in the amount and frequency of precipitation and alteration of surface temperatures. In South America, most of the studies of the effects of LUCC on the local and regional climate have focused on the Amazon region (54 studies), whereas LUCC within non-Amazonian regions have been largely undermined regardless their potential importance in regulating the regional climate (19 studies). We estimated that 3.6 million km2 of the original natural vegetation cover in non-Amazonian South America were converted into other types of land use, which is about 4 times greater than the historical Amazon deforestation. Moreover, there is evidence showing that LUCC within such fairly neglected ecosystems cause significant reductions in precipitation and increases in surface temperatures, with occasional impacts affecting neighboring or remote areas. We explore the implications of these findings in the context of water security, climatic extremes and future research priorities.

Land use and land cover change impacts on the regional climate of non-Amazonian South America: a review.

The current global gold rush, driven by increasing consumption in developing countries and uncertainty in financial markets, is an increasing threat for tropical ecosystems. Gold mining causes significant alteration to the environment, yet mining is often overlooked in deforestation analyses because it occupies relatively small areas. As a result, we lack a comprehensive assessment of the spatial extent of gold mining impacts on tropical forests. In this study, we provide a regional assessment of gold mining deforestation in the tropical moist forest biome of South America. Specifically, we analyzed the patterns of forest change in gold mining sites between 2001 and 2013, and evaluated the proximity of gold mining deforestation to protected areas (PAs). The forest cover maps were produced using the Land Mapper web application and images from the MODIS satellite MOD13Q1 vegetation indices 250 m product. Annual maps of forest cover were used to model the incremental change in forest in ?1600 potential gold mining sites between 2001?2006 and 2007?2013. Approximately 1680 km2 of tropical moist forest was lost in these mining sites between 2001 and 2013. Deforestation was significantly higher during the 2007?2013 period, and this was associated with the increase in global demand for gold after the international financial crisis. More than 90% of the deforestation occurred in four major hotspots: Guianan moist forest ecoregion (41%), Southwest Amazon moist forest ecoregion (28%), Tapaj?s?Xing? moist forest ecoregion (11%), and Magdalena Valley montane forest and Magdalena?Urab? moist forest ecoregions (9%). In addition, some of the more active zones of gold mining deforestation occurred inside or within 10 km of ?32 PAs. There is an urgent need to understand the ecological and social impacts of gold mining because it is an important cause of deforestation in the most remote forests in South America, and the impacts, particularly in aquatic systems, spread well beyond the actual mining sites.

/pdf/global-demand-for-gold-is-another-threat-for-tropical-1wkecgavg9.pdf

Global demand for gold is another threat for tropical forests

Selecting economically viable forest management strategies that deliver carbon storage and biodiversity benefits can be a difficult task. Now, research in the western Andes of Colombia shows that naturally regenerating forests can quickly accumulate carbon and support diverse ecological communities at minimal cost. Climate change and biodiversity loss can be addressed simultaneously by well-planned conservation policies, but this requires information on the alignment of co-benefits under different management actions1,2,3. One option is to allow forests to naturally regenerate on marginal agricultural land: a key question is whether this approach will deliver environmental co-benefits in an economically viable manner4,5,6,7. Here we report on a survey of carbon stocks, biodiversity and economic values from one of the world’s most endemic-rich and threatened ecosystems: the western Andes of Colombia. We show that naturally regenerating secondary forests accumulate significant carbon stocks within 30 years, and support biodiverse communities including many species at risk of extinction. Cattle farming, the principal land use in the region, provides minimal economic returns to local communities, making forest regeneration a viable option despite weak global carbon markets. Efforts to promote natural forest regeneration in the tropical Andes could therefore provide globally significant carbon and biodiversity co-benefits at minimal cost.

Cheap carbon and biodiversity co-benefits from forest regeneration in a hotspot of endemism

Background 
Monitoring land change at multiple spatial scales is essential for identifying hotspots of change, and for developing and implementing policies for conserving biodiversity and habitats. In the high diversity country of Colombia, these types of analyses are difficult because there is no consistent wall-to-wall, multi-temporal dataset for land-use and land-cover change.
Methodology/Principal Findings 
To address this problem, we mapped annual land-use and land-cover from 2001 to 2010 in Colombia using MODIS (250 m) products coupled with reference data from high spatial resolution imagery (QuickBird) in Google Earth. We used QuickBird imagery to visually interpret percent cover of eight land cover classes used for classifier training and accuracy assessment. Based on these maps we evaluated land cover change at four spatial scales country, biome, ecoregion, and municipality. Of the 1,117 municipalities, 820 had a net gain in woody vegetation (28,092 km2) while 264 had a net loss (11,129 km2), which resulted in a net gain of 16,963 km2 in woody vegetation at the national scale. Woody regrowth mainly occurred in areas previously classified as mixed woody/plantation rather than agriculture/herbaceous. The majority of this gain occurred in the Moist Forest biome, within the montane forest ecoregions, while the greatest loss of woody vegetation occurred in the Llanos and Apure-Villavicencio ecoregions.
Conclusions 
The unexpected forest recovery trend, particularly in the Andes, provides an opportunity to expand current protected areas and to promote habitat connectivity. Furthermore, ecoregions with intense land conversion (e.g. Northern Andean Paramo) and ecoregions under-represented in the protected area network (e.g. Llanos, Apure-Villavicencio Dry forest, and Magdalena-Uraba Moist forest ecoregions) should be considered for new protected areas.

https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0043943&type=printable

Ana María Sánchez-Cuervo

Papers

Land cover change in Colombia: surprising forest recovery trends between 2001 and 2010.

Balancing multi-species connectivity and socio-economic factors to connect protected areas in the Paraguayan Atlantic Forest

How 30 years of land-use changes have affected habitat suitability and connectivity for Atlantic Forest species

Habitat assessment for threatened species in the cross-border region of the Atlantic Forest