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Caveat lector; or, the Linnean origin of the myth of Tournefort as a precursor of von Humboldt
Full text linkJoseph Pitton de Tournefort (1656-1708) is frequently mentioned in biogeography and ecology among those who, before von Humboldt, paralleled the elevational organization of vegetation to its latitudinal zonation on the basis of observations made on Mount Ararat and presented in his Relation d'un voyage du Levant (1717). However, as already noticed in overlooked notes by Hooker (1881) and Hemsley (1896), there is no hint to this correspondence in Tournefort’s description of his ascent of Mount Ararat. Linnaeus (1744) was the first author who, without any plausible reason, attributed the idea of this parallelism to Tournefort. Based on Linnaeus’ work, Mirbel (1815), von Humboldt (1816), Schouw (1823) and Forbes (1846) repeated this wrong credit. Works by these early authors have in turn generated an intricate pathway of repetition of original Linnaeus’ error until nowadays. Along with Tournefort, Linnaeus cited Cesalpino (1583), as one who found floral similarities between northern lowlands (Sweden) and southern mountains (Tuscany). However, there is no passage in Cesalpino that might suggest that he made any comparison between the Italian and Swedish floras, although it is possible that Linnaeus used Cesalpino’s observations on the Italian flora to make a parallelism with the Swedish one. Cesalpino’s recognition of the existence of allied species placed at different elevations may suggest that he has anticipated, by centuries, the concept of vicariance. 
Are planar areas adequate for the species-area relationship?
No full textThe species-area relationship (SAR) is one of the best documented patterns in macroecology and has wider applications. Measures of areas used in SARs are planar surfaces, not true surface sizes. To explain this difference I assimilated islands to cones, where the cone base is the planar area, and the cone lateral surface is the actual island area. Then, I applied the power function to 20 real-world archipelagos using both the island planar area and the lateral surface area of a cone calculated using island elevations. Although the cone model is obviously a simplistic proxy for the actual area size of islands, this simple exercise shows how a model, which increases only marginally the area sizes in SARs, may improve the fit and change the estimated parameters, suggesting the opportunity of searching for more realistic values of areas than the simple planar surface for modelling SARs
Biogeography and conservation of endemic tenebrionid beetles (Coleoptera Tenebrionidae) on east Mediterranean Islands
No full textThe aim of this paper was to investigate geographic patterns of tenebrionid (Coleoptera Tenebrionidae) endemicity on the Aegean Islands (Greece). These beetles are known to have an impressive non adaptive radiation on the Aegean Islands. Levels of endemism appeared poorly influenced by present geography or island shape, while past land configurations appeared to have a major role, as expected for flightless beetles, more affected by past vicariance events than by present dispersal. Extinction events observed in the study area exceeded largely those which a model based on the species-area relationship could predict even for a disproportionate amount of area (habitat) loss, possibly as a consequence of the particular relict condition of the Aegean fauna
A new method to identify important conservation areas applied to the butterflies of the Aegean Islands (Greece)
No full textSelection of priority areas in conservation biology should incorporate an evaluation of the contribution of imperilled species to the total species richness. To rank areas according to their conservation value, a new index - termed biodiversity conservation concern (BCC) - is proposed. This index combines the conservation status of each species belonging to a given species assemblage with the total species richness. In the BCC index, species are classified into categories of endangerment and weighted by the respective risk of extinction. The new method is applied here to the butterflies of the Aegean Islands (Greece) using different (national and international) red lists. Results were consistent with both classifications based on multivariate analyses and findings from other researches. The BCC index has two important features: it assigns a biodiversity value to an area based on many species, and it facilitates multi-species assessments of ecological effects
A comparison of relict versus dynamic models for tenebrionid beetles (Coleoptera : Tenebrionidae) of Aegean Islands (Greece)
No full textThis paper analyses the species-area relationship in the Aegean tenebrionids in order to discriminate between relict and dynamic models, Using different statistical approaches, the following eco-geographic variables were tested as predictors of the tenebrionid richness on 32 Aegean Islands: latitude, longitude, area, maximum elevation, distance to the mainland, and distance to the nearest island. Area was identified as an important predictor, while neither distance to the mainland nor distance to the nearest island was identified as of any statistical importance in affecting tenebrionid richness. Thus, as proposed for other very sedentary animals inhabiting this archipelago such as land snails, a relict model is postulated. As most tenebrionids have extremely limited ability to actively disperse over the sea, ancestral species have probably colonised the Aegean Islands by means of land-bridges during Pleistocene falls in the sea level
Historical relationships of African mountains based on cladistic analysis of distributions and endemism of flightless insects
No full textDistributional and taxonomic information on flightless insects were used in a cladistic analysis of distributions and endemism (CADE) to generate a testable hypothesis of area-relationships for the central eastern African mountains. A tree was obtained where the relationships of all mountain areas were resolved according to a hierarchical, time-dependent sequence of vicariance events. It is inferred that most of the present species distributions originated as a consequence of forest fragmentation during the Pleistocene cycles of cooling and drying of the climate. Around 150 000-130 000 years ago, Africa experienced colder, dryer conditions than present conditions. This could have been the first stimulus in the last glacial/interglacial cycle for a large vicariance among different mountain systems. About 130 000 years ago, a warmer, moister phase than the present began, and this condition could have represented an important occasion for the widespread distribution of some genera and species among neighbouring mountain systems. The last glacial maximum confined most species to single refugial montane areas. A resumption of warm, moist conditions probably led up to the Holocene `optimum' of greater rainforest extent allowing some species to disperse again among adjacent mountain peaks
Temporal and spatial variations in darkling beetle predation by kestrels and other raptors in a Mediterranean urban area
No full textThe aim of this research is to analyze raptor predation on darkling beetles in the Mediterranean urban area of Rome. Urban Rome harbors a number of darkling beetle species, many of which are successful city-colonizing species. Both the kestrel and little owl prey on many soil dwelling darkling beetle species, especially in ruderal and built-up areas. In contrast, the tawny owl spends a great deal of time in wooded areas, preying on arboreal species. Kestrel predation on darkling beetles in a city-center ruderal site showed a decreasing diversity from summer to winter, in accordance to the termophilic preferences of such insects. In general, darkling beetles may represent a significant food source for urban kestrels in Mediterranean areas
Spatial patterns of diversity in the tenebrionid beetles (Coleoptera, Tenebrionidae) of the Aegean Islands (Greece)
No full textQuestion: How do present and historical factors influence beta and gamma diversity of strictly resident animals on a land-bridge archipelago? Data description: Islands were characterized in terms of present geography, shape, area size, habitat diversity and paleogeography. Diversity patterns are based on 170 tenebrionid taxa from 32 islands (Greece). Search method: The influence of present eco-geographic variables on gamma diversity (species numbers) was assessed using pairwise correlations, multiple regressions and path analysis. Canonical correspondence analysis was applied to study the influence of present and past island characteristics (represented by multidimensional spaces) on beta diversity (calculated as biogeographic similarity among islands). Fuzzy analysis was applied to determine island groupings based on beta diversity. Conclusions: Larger islands have more species because they have more habitats. Distance and shape effects were small. Thus present colonization processes do not play a substantial role. Tenebrionids colonized the islands by Pleistocene land-bridges. Larger islands retained more species. Beta diversity was moulded mostly by paleogeographic conditions. The Aegean Islands were subject to a twofold colonization process. Relatively few species have been able to cross the middle Aegean sea barrier to colonize islands far from their mainland source
Assessing priority areas by imperilled species: insights from the European butterflies
No full textBiodiversity hotspots have been variously defined in terms of species richness, endemic species or imperilled species. The use of imperilled species to locate priority areas is particularly problematic, because an area that hosts a large number of imperilled species is likely to be under severe threats, making less effective conservation efforts. A possibly way to answer this problem is to assess species threats at two spatial scales. Then, areas which host concentrations of species that are imperilled at the larger scale, but not at the smaller scale, can be considered as priority areas where conservation efforts are expected to be more effective. An application of this procedure to the European butterfly fauna with the Biodiversity Conservation Concern index calculated with two IUCN red listings (European and national) allowed the construction of a four-celled model that reflects different types of conservation priority. This combined use of international and regional red lists may be a tool to make practical decisions (e.g. allocation of funds or legislative actions) to preserve imperilled species
Beetle Species–Area Relationships and Extinction Rates in Protected Areas
Full text linkThe species–area relationship (SAR, i.e., the increase in species richness with area) is one of the most general ecological patterns. SARs can be used to calculate expected extinction rates following area (habitat) loss. Here, using data from Italian reserves, extinction rates were calculated for beetle groups with different feeding habits: Carabidae (terrestrial predators), Hydradephaga (aquatic predators), coprophagous Scarabaeoidea (dung feeders), phytophagous Scarabaeoidea (herbivores), and Tenebrionidae (detritivores). The importance of other factors besides area (namely latitude and elevation) was investigated. Reserve area was recovered as an important predictor of species richness in all cases. For Carabidae, Hydradephaga, and Tenebrionidae, elevation exerted a negative influence, whereas latitude had a negative influence on coprophagous Scarabaeoidea and Tenebrionidae, as a consequence of current and historical biogeographical factors. Extinction rates were higher for dung beetles, due to their dependence on large grazing areas, and Tenebrionidae, due to their low dispersal capabilities. The lower extinction rates predicted for Carabidae, phytophagous Scarabaeoidea, and Hydradephaga can be explained by their higher dispersal power. If other variables besides area are considered, extinction rates became more similar among groups. Extinction rates by area loss are always relatively low. Thus, in reserves with few species, many local extinctions might be unnoticed
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