Biodiversity and Conservation

The Neotropical realm hosts some of the Earth’s most species-rich biodiversity hotspots, with vascular epiphytes significantly contributing to this diversity, regionally accounting for up to 39% of the vascular flora. However, many regions of the Neotropics where epiphytic species of restricted distribution are reported coincide with threatened ecosystems, such as the tropical montane cloud forest. Moreover, epiphytes may be especially vulnerable to land use and climate change impacts due to their dependence on host trees. We assessed the conservation status of vascular epiphytes in the Neotropics for the families that represent over 80% of the global epiphyte diversity (Araceae, Bromeliaceae, Orchidaceae, Piperaceae, and Polypodiaceae) and identified geographical centres of accumulation of threatened epiphyte species. We gathered information from free-access web repositories, specific epiphytic plant databases, and scientific and grey literature. We assessed the extinction risk of 11,446 epiphyte species following IUCN Red List guidelines, using Criterion B (geographic range size). We found nearly 60% (6,721 species) to be threatened, with 1,766 critically endangered (CR), 3,537 endangered (EN), and 1,418 vulnerable (VU). The threatened species are mainly found in the centres of endemism of vascular epiphytes in Central America, the northern Andes, and the Atlantic Forest. Our study emphasises that the centres of threatened species largely coincide with diversity hotspots, highlighting epiphytes as an especially vulnerable group that requires urgent conservation actions.

Based on cartography, floristic inventory and vegetation analysis in the north and south of the Eastern Domain of Madagascar we identified three original tropical rainforest types which are among the world's most biodiverse known sites for plants: the littoral forest on sand, the lowland forest on gneiss and the lowland forest on basalt. Floristic and structural comparisons were conducted on 37 plots of 50×10m. Multivariate analysis indicates that floristic composition is correlated with abiotic factors of rainfall, latitude, soil composition, and marine influence; the structure of the undergrowth is generally homogeneous and the canopy is more or less open. Many reserves must be created on gneiss, sand and basalt all along the eastern coast to preserve biodiversity from the deforestation process. On basalt, this is especially urgent because about only 10 000 ha of a very ancient forest that shelters numerous botanical novelties remain today.

Stream geomorphology and fluvial processes in Australia have generallybeen modified substantially since European settlement. In the case of theSouthern Tablelands of New South Wales, in southeastern Australia, detailednotes of early explorers and settlers and early survey maps have providedinsight into the nature of these changes. Early explorers described most streamsin this area as 'chains-of-ponds'. These are ponds connected byshort lengths of channel or divided by grassy intervals. Many of these systemswere converted to incised channels after Europeans arrived. An examination ofthe life history characteristics of frogs and their physiological limitationsprovides insight into how these changes are likely to have affected froghabitat. Chains-of-ponds provided permanent breeding ponds for frog species withextended larval stages. The environment surrounding these ponds floodedregularly, providing breeding habitat for species that can exploit ephemeralwaterbodies. Flood waters and saturated soil also created moist, well-vegetatedenvironments for adult frogs during the non-breeding season. Human impacts andlandscape modification led to channel incision of chain-of-pond systems andresulted in many physical changes in pond characteristics, includingavailability, permanency, structural complexity and flow dynamics. Theimplications of these changes are discussed in this paper. Hypotheses aredeveloped on frog species susceptibility to landscape change associated withchannel incision of chain-of-pond systems.

Most studies analyzing patterns in biotic homogenization of fish communities have used large-scale approaches, while the community-level effects of species introductions and local extinctions within river basins have been sparsely analyzed. In this article, we examine patterns in freshwater fish α- and β-diversity in relation to the presence of reservoirs in a Mediterranean river (Guadiana river; Iberian Peninsula). We used fish samples from 182 river localities and 59 reservoir ones to address two main questions: (i) do reservoirs favor the establishment of invasive fish species?; and (ii) do reservoirs bear taxonomically homogenized fish communities? Although total species richness was not different between rivers and reservoirs, the latter had more invasive species and less native ones. Fish species found in reservoirs tended to be larger ones, but invasive species of any size showed higher preferences for reservoirs. Native species that were rare or absent in reservoirs were those that showed higher sensitivity to invasive species in rivers. Reservoir fish communities were taxonomically homogenized in relation to river ones, both when considering all fish species and using only natives or only invasive ones. Our results suggest that invasive species occupying reservoirs constitute an ecological filter excluding most native species from such systems. Invasive species in the study area are often widely introduced elsewhere, while native species found in reservoirs are congeneric and ecologically similar to those found in other Iberian studies. Thus, we conclude that reservoirs promote taxonomic homogenization at multiple spatial scales, while could also be promoting the functional homogenization of Iberian fish communities.

Fonio millet (Digitaria exilis Stapf, Digitaria iburua Stapf) is known in Togo far several centuries and has played a strategic role in the household food security mainly in rural areas. Using Participatory Research Appraisal (PRA) tools and techniques, 55 villages randomly selected in the two production zones of Togo were surveyed to document the ethnobotanical and indigenous knowledge related to its production, diversity, use and conservation. For all of the ethnic groups involved in fonio production in Togo (Akposso and Akébou in the south; Losso-Nawda, Lamba, Tamberma, Tchokossi and Gangan in the north), the crop has a high sociocultural value. The fonio genetic diversity being managed by the farmers seems important as 42 landraces were recorded. Two lines of origin that contributed to this current genetic diversity (local domestication or introduction from neighbouring countries) were reported by the farmers. Cooking qualities, growth cycle, colour and size of the grains are the main criteria used by farmers to describe varieties. According to farmers, fonio production and diversity are being regressing because of several constraints of which the most important are lack of adequate harvest, threshing and processing technologies and development of pests and diseases. The important ethnobotanical and indigenous data recorded will be useful in accessing the genetic diversity of the crop in Togo and in defining appropriate strategies for its conservation on farm.

Dullinger et al. (Proc Nat Acad Sci USA 110:7342–7347, 2013) showed that current proportions of threatened species in European countries are more correlated to socio-economic pressures calculated a century ago than to current socio-economic pressures. These results could have important impacts on future political decisions, yet the statistical analyses used may be strongly impacted by pseudo-replication and over-dispersion of data. I reanalysed Dullinger et al.’s data using generalised linear mixed models accounting for pseudo-replication and over-dispersion. These new statistical models indicated that socio-economic pressures had a much less clear impact on proportions of threatened species than indicated by Dullinger et al. In many cases, the effects of socio-economic pressures even vanished. Dullinger et al. (Proc Nat Acad Sci USA 110:7342–7347, 2013)’s results are actually much less “considerable” than their paper implies and therefore should be viewed with caution. Ecologists should more often incorporate pseudo-replication and overdispersion in their statistical analyses.

Patterns in phylogenetic diversity are poorly known for many taxonomic groups, including hyperdiverse insect taxa. We contrasted patterns in the species richness and phylogenetic diversity of provincial beetle faunas in northern Europe (54°N to 71°N). We found that species richness and phylogenetic diversity varied rather predictably along ecogeographical gradients, with species richness and a proxy measure of phylogenetic diversity, average taxonomic distinctness (AvTD), decreasing from south to north and being strongly positively related to maximum temperature. A proxy measure of variation in phylogenetic diversity, variation in taxonomic distinctness (VarTD), was also strongly related to maximum temperature, but the relationship was negative. This was a novel finding, showing a reversed latitudinal gradient in biodiversity. In more than half of the provinces, AvTD value was significantly less than expected by chance. Also, more than half of the provinces showed significantly higher VarTD values than expected based on random draws of species. Our results showed that the phylogenetic diversity of beetle faunas is rather strongly associated with climatic gradients at high latitudes. Given that climatic variability and temperature extremes are correlated with phylogenetic diversity, climate change is likely to modify strongly this facet of diversity. Average phylogenetic diversity is likely to increase in the northernmost parts of the study area if climate and vegetation become more suitable for many southern beetle species. Our statistical approach to test chance expectations based on random draws of species from larger-scale species pool is highly flexible in tackling this question when true phylogenies are not available.

Iran is a mountainous country. Zagros and Alborz mountains reach altitudes of more than 4,000 m. Alpine regions are above timber-line, which is not easy to recognize, since aridity is prominent in most regions. The alpine zone in Alborz lies between 3,000 and 4,000 m, the nival zone is above 4,000 m, locally varying by some hundred meters. A first evaluation of vascular flora shows that 682 species belonging to 193 genera and 39 families are known from the alpine zone of Iran. The alpine zone is commonly characterized by many species of hemicryptophytes and thorny cushions. Species numbers decline very strongly with increasing altitude. In this paper biogeographical patterns of the alpine flora of Iran have been discussed and distribution maps of 44 species are illustrated. New data indicate a transitional situation of the Iranian mountains between Anatolia/Caucasus and the Hindu Kush, but with a strong own element with high endemism and remarkable relict species. Ca. 58% of the alpine flora of Iran are endemic and subendemic. The Zagros Mountains harbor high endemism which justify considering this area as a separate floristic province. Based on the evaluation of published data from 682 known alpine species ca. 160 species have been known only by one record, 110 species by 2–3 records and 87 endemic species have been known only based on the type location. These plants need a strong conservation and protection management since the fragile ecosystems are often very restricted, small and very isolated, nonetheless grazing and overgrazing are still common threats.

The mollusc Patella ferruginea, endemic to the Mediterranean, is the most endangered marine species on the list of the European Council Directive 92/43/EEC and it is under serious risk of extinction. In spite of the low abundances and restricted distribution of this limpet, important populations have been found in the harbour of Ceuta, north Africa. The main objective of the present study was to characterise, for the first time, the effects of sewage pollution on P. ferruginea and related limpet species, and to evaluate the potential value of these limpet assemblages as bioindicators, using univariate and multivariate analyses. Physicochemical parameters and limpets were sampled in nine stations located at 0, 1, 2, 4, 8, 16, 32, 64 and 128 m away from the discharge point of a sewage effluent in Ceuta harbour. The stations closer to the outfall (0, 1, 2, 4 and 8) were characterised by higher values of turbidity, phosphate and ammonia in the water column, and organic matter, faecal coliforms and faecal Streptococci in sediments. A total of six limpet species were found and studied (Patella ferruginea, P. caerulea, P. nigra, P. rustica, P. ulyssiponensis and Siphonaria pectinata); the number of limpet species increased with increasing distance from the outfall, while diversity and evenness reached the highest values at intermediate sites. Siphonaria pectinata and P. caerulea were the most resistant and abundant species, while P. ferruginea was the most sensitive species to sewage pollution, only found at stations from 32 to 128 m. The distribution of this endangered limpet seems mainly affected by the pollution gradient, and not by the competition with the remaining limpets. The results of this study should be taken into account in future programmes of management and conservation of P. ferruginea.

Decline of soil microarthropod biodiversity is described in the sequence: old forest stands, low-input grasslands, high-input grasslands (with and without the use of persistent pesticides). With this expected trend of declining biodiversity, the patterns of species losses are analysed with the use of classifications of life-history tactics, feeding guilds and tolerances to drought. Species intolerant to drought are absent in grasslands, but present in old forest stands. Also the fraction of thelytokously reproducing microarthropods is higher in old forest stands compared with low-input grasslands. The main difference between low-input and high-input grasslands is found in the feeding guild structure of the community. Low-input grasslands are dominated by (herbo-) fungivorous grazers, whereas high-input grasslands are dominated by fungivorous browsers. Application of DDT in high-input grasslands shows a high density of microarthropods with a high fraction of thelytokous reproduction, associated with a decrease in genetic variation in a thelytokously reproducing species. Patterns in species losses, the species filters, are explained and discussed. It is shown that the decline of biodiversity is not a randorn loss of species but follows and identifiable pattern.