Search results for "Conservation"

Quantifying the Indicator Power of an Indicator Species

2009

Biodiversity indicator species are needed for classifying biotopes and sites for conservation, and a number of methods have been developed for determining indicator species for this purpose. Nevertheless, in addition to site classification, there is sometimes a need to define an indicator species that indicates the occurrence of another species. For example, when a species of interest (target species) is difficult to detect or identify, a reliable indicator species can function as a tool that saves time and money. We derived a method that provides a quantitative measure of the indicator power (IP) of an indicator species for the target species or any species assemblage. We calculated the me…

Effects of Local Disturbance of Tropical Forests on Frugivores and Seed Removal of a Small-Seeded Afrotropical Tree

2008

Small-scale, local disturbance of tropical forests, for example from selective logging, is widespread, but its effects on biodiversity and ecosystem function have rarely been studied. In 3 East African tropical rainforests, we investigated the effect of different levels of local forest disturbance on the frugivore community and on tree visitation and fruit removal rates of the small-seeded tree Celtis durandii. We quantified birds and primates in little and heavily disturbed sites, distinguishing between forest specialists, forest generalists, and forest visitors. We quantified frugivorous tree visitors and seed removal rates of C. durandii trees in the same sites. Forest disturbance reduce…

2015

Prey preference of top predators and energy flow across habitat boundaries are of fundamental importance for structure and function of aquatic and terrestrial ecosystems, as they may have strong effects on production, species diversity, and food-web stability. In lakes, littoral and pelagic food-web compartments are typically coupled and controlled by generalist fish top predators. However, the extent and determinants of such coupling remains a topical area of ecological research and is largely unknown in oligotrophic high-latitude lakes. We analyzed food-web structure and resource use by a generalist top predator, the Arctic charr Salvelinus alpinus (L.), in 17 oligotrophic subarctic lakes…

Mapping floristic diversity: a case study in Sicily

2021

This paper presents an operational methodology to map and analyze the floristic richness of “target species” in Natura 2000 sites, making use of G.I.S. tools and procedures. A Floristic diversity map (scale 1:50,000), covering an area of 612 km2, was produced by a team of experts as part of the management plans of “Madonie Mountains” Sites of Community Importance (SCIs), located in Sicily (Italy). The primary grid map represents the richness of “target species”, which include species of Community interests, taxa on the National Red List, endemic and threatened, species protected under International Conventions, taxa of phytogeographic importance. Secondary data frames include a three-dimens…

Assessing the efficacy of direct conservation interventions: clutch protection of the leatherback marine turtle in the Dominican Republic

2014

AbstractThe beaches of Jaragua National Park in the Dominican Republic are the country's last known major nesting site for the leatherback marine turtle Dermochelys coriacea. This nesting aggregation is threatened by widespread illegal egg take, and clutch relocation and artificial incubation have been carried out as protection measures since 1974. We assess the efficacy of such efforts and investigate how artificial incubation may be influencing the success and sex ratios of clutches. We compare hatching success, incubation duration and embryo mortality in in-situ clutches (n = 43) with those incubated artificially at sites in the east and west of the Park (n = 35 and n = 31, respectively)…

The impact of economic, social and political factors on the landscape structure of the Vidzeme Uplands in Latvia

2005

Abstract Changes in landscape structure in a typical part of the Vidzeme Uplands in central Latvia during the 20th century are analysed and anticipated changes in the 21st century are projected. Forest areas gradually increased in the Vidzeme Uplands over the course of the 20th century. This increase was associated with several factors: the economic policy in Latvia during the 1930s, the exile of farmers in 1940 and 1949 after the Soviet occupation of Latvia, the aggregation of land into collective farms, the amalgamation of small collective farms, the formation of large-scale Soviet collective farms, and widespread land melioration. Since land reform in the 1990s, following the restoration…

Dispersal of larval and juvenile seabream: Implications for Mediterranean marine protected areas

2015

International audience; In the marine context, information about dispersal is essential for the design of networks of marine protected areas (MPAs). Generally, most of the dispersal of demersal fishes is thought to be driven by the transport of eggs and larvae in currents, with the potential contribution of dispersal in later life stages relatively minimal.Using otolith chemistry analyses, we estimate dispersal patterns across a spatial scale of approximately 180 km at both propagule (i.e. eggs and larvae) and juvenile (i.e. between settlement and recruitment) stages of a Mediterranean coastal fishery species, the two-banded seabream Diplodus vulgaris. We detected three major natal sources …

Relationships between climatic parameters and forest vegetation: application to burned area in Alicante (Spain)

2000

Abstract The main aims of this study is to examine the variability of normalized difference vegetation index (NDVI) on forest vegetation in Alicante (Spain) between 1984 and 1994 and to analyse the influence of climatic parameters in the regeneration of forest areas burned by fires. The zone of study is located between XUTM (m) 730400-760400 and YUTM (m) 4274000-4304000 and is characterised by a great topographic complexity that leads to diverse microclimatic conditions. In this area, the maximum annual rainfall of the Valencian Community is recorded, reaching 850 mm of average annual rainfall ( Belda, 1997 ). We examined the spatial and temporal analyse of rainfall and soil moisture over t…

CONSTRUCTING, BOOTSTRAPPING, AND COMPARING MORPHOMETRIC AND PHYLOGENETIC TREES: A CASE STUDY OF NEW WORLD MONKEYS (PLATYRRHINI, PRIMATES)

2005

Morphometric data sets are often phenetically analyzed by using various kinds of spatial, metric, or nonmetric multivariate analyses. Such methods produce results that are difficult to compare directly with molecular or morphological phylogenetic hypotheses, which are usually expressed by using nonspatial tree representations. Therefore, it is useful in a comparative approach to analyze, and above all to visualize, morphometric pairwise relationships as tree structures. For this purpose, several additive or ultrametric methods exist, which often return different topologies for the same data set. Objective criteria are thus needed to identify the tree-building algorithm (or algorithm family)…

Investigating the origin of parthenogenesis and ploidy level in Dahlica fennicella (Lepidoptera: Psychidae)

2013

The theories for the predominance of sexual reproduction predict that parthenogens should have no long-term evolutionary potential due to the lack of genetic recombination, despite short term advantages. Although parthenogenesis is rare among high order animals, true parthenogens can be found in various taxa. The intriguing question of the proliferation and persistence of parthenogenetic species needs investigation. An ideal species for such research is a parthenogenetic mont Dahlica fennicella that appears to be as equally successful as other coexisting sexual species. We investigated whether high ploidy level of D. fennnicella is due to hybridization between closely related sexual species…