Towards the identification and assessment of HNV Dehesas: a meso-scale approach

Iberian dehesa and montado are paradigmatic high nature value (HNV) agroforestry systems in Europe. Nevertheless their conservation status is uncertain as a consequence of their typological variety, different intensity of management practices on the ground, and other ongoing processes challenging their long-term sustainability. The existing broad gradients of dehesa and montado types impose difficulties in estimating not only their distribution and extent, but also their condition, since probably not all these agroforestry systems should readily be considered as HNV. Tackling with these difficulties, we explore a methodology based on GIS-analyses of land cover cartographies to estimate the extent and condition of dehesa farmland in an area covering ten municipalities in northern Andalusia region (Spain) based on: (1) integration of available thematic maps to obtain an improved land-use cartography; (2) application of GIS map generalization techniques to delimit potential HNV farmland types; (3) definition and calculation of several indices of ‘structural diversity’ and ‘impact’ within patches of dehesa farmland; (4) automatized weighted integration of indices to obtain a cartography assessing dehesa’s HNV in an ordinal scale from very low to very high. Estimated natural value was significantly worse for cultivated dehesas, with dehesas of pastures showing higher structural diversity and lower impact indices. Weaknesses and strengths of the proposed methodology are discussed.     

Using the high conservation value forest concept and Pareto optimization to identify areas maximizing biodiversity and ecosystem services in cork oak landscapes

Montados are silvo-pastoral systems, typical of the western Mediterranean Basin. When well managed, these ecosystems provide relevant ecosystem services and biodiversity conservation. In the northern part of the Mediterranean Basin, cork oak areas are mainly privately owned and a source of income to landowners, chiefly through cork and livestock production. Sustainable use is essential to maintain the ecological sustainability and socio-economic viability of these ecosystems. Biodiversity conservation and non-provisioning ecosystem services may generate additional incentives promoting sustainable use and conservation of montados, but require adequate mapping and identification. The high conservation value forest (HCVF) framework allows systematic inventory of biodiversity and non-provisioning ecosystem services and is widely applied in forest ecosystems. Here we exemplify the application of HCVF to the cork oak landscape of southern Portugal using a WebGIS tool that integrates the HCVF framework, in conjunction with Pareto optimization, to identify areas important for the conservation of biodiversity and ecosystem services. We present a case study using threatened bird and reptile species, as examples of biodiversity attributes, and carbon storage and water recharge rate of aquifers, as examples of ecosystem services attributes. We identify those areas in a cork oak landscape of southern Portugal where biodiversity and ecosystem services attributes are optimized. These areas can be prioritized for implementing conservation mechanisms, such as payment for ecosystem services, to promote sustainable forest management.     

Development of digestive enzyme activity in spotted rose snapper,Lutjanus guttatus (Steindachner, 1869) larvae

We describe digestive enzyme activity during the larval development of spotted rose snapper, Lutjanus guttatus. Trypsin, chymotrypsin, leucine aminopeptidase, pepsin, amylase, lipase, and acid and alkaline phosphatase activities were evaluated using spectrophotometric techniques from hatching through 30 days. The spotted rose snapper larvae present the same pattern of digestive enzyme activity previously reported for other species in which pancreatic (i.e., trypsin, chymotrypsin, amylase, and lipase) and intestinal (i.e., acid and alkaline phosphatases and leucine aminopeptidase) enzymatic activities are present from hatching allowing the larvae to digest and absorb nutrients in the yolk-sac and live prey by the time of first feeding. The digestive and absorption capacity of the spotted rose snapper increases during the larval development. A significant increase in individual activity of all enzymes occurs at 20 DAH, and around 25 DAH, the juvenile-type of digestion is observed with the appearance of pepsin secreted by the stomach, suggesting that maturation of the digestive function occurs around 20–25 DAH. Our results are in agreement with a previous suggestion that early weaning may be possible from 20 DAH. However, the patterns of enzymatic activities reported in our study should be considered during the formulation of an artificial diet for early weaning of the spotted rose snapper.