Extending the Namibian protected area network to safeguard hotspots of endemism and diversity

Namibia's state protected area network (PAN) covers 13.8% of the country's land area, but is seriously inadequate as a basis for effective biodiversity conservation. The early parks system was not designed with biological diversity in mind, and reflects instead a history of ideological, economic and veterinary considerations. Currently, parks in the Namib Desert biome make up 69% of the PAN, while savanna and woodland biomes are somewhat underrepresented (7.5 and 8.4% of their respective land areas), and the Karoo biome is badly underrepresented (1.6%). Four of 14 desert vegetation types are comprehensively protected, with 67 to 94% representation in the PAN, yet six savanna types have 0 to 2% representation by area. Mountain Savanna, a vegetation type unique to Namibia, is wholly unprotected. The status of two marine reserves, which in theory protect only 0.01% of Namibia's marine environment, needs clarification and augmentation with new reserves. Nearly 85% of Namibia's land is zoned for agriculture, so effective biodiversity protection means working outside the PAN to improve the sustainability and diversity of farming practices. Wildlife conservancies on commercial and communal farmlands show excellent potential to mitigate the ecological skew in the state PAN, with the ecological management of large areas being decentralized to rural communities in habitats otherwise neglected for conservation. Two important endemism zones, the Kaoko escarpment and coastal plain and the Sperrgebiet succulent steppe, plus the species-rich Caprivi area, offer three valuable opportunities for regional consolidation of protected areas into transboundary 'peace parks' or biosphere reserves.     

Threatened plants of New Caledonia: Is the system of protected areas adequate?

With 76% of its 3063 native species of flora endemic, the New Caledonia biodiversity hotspot has long been recognized as having a high potential for conservation. Under the new IUCN Red List categories, 25% of the endemic plants are at risk (Conservation Dependent, Vulnerable, Endangered, Critically Endangered), and five species are already extinct. A review of their distribution demonstrates that 83% of the threatened species do not occur at all in a conservation area, and only 11% have their conservation status improved by a protected area. The protected area network is geographically and floristically very unbalanced, with the rainforest and high altitude maquis in the south concentrating most of the conservation effort. Conversely, the middle and northern segments of the island, as well as all of the dry west coast, are left without adequate conservation area. Two vegetation types, the sclerophyll forest and the unique low/middle altitude maquis, are virtually totally unprotected. We conclude that the current network of protected areas needs to be considerably expanded, in terms of both geographical/floristic subregions within New Caledonia and vegetation type covered. With only 54% of the conservation area covered by strict mining restrictions, existing reserves need to have their conservation efficiency improved by a more vigorous enforcement of their status, and by extending mining bans to all of them.     

Do leaf margins of the temperate forest flora of southern South America reflect a warmer past?

Aim   Our aims were: (1) to characterize the linear relationship between the proportion of woody dicotyledonous species with entire-margined leaves ( E ) and mean annual temperature (MAT) from a southern temperate flora that still harbours many lineages that originated under warmer climates; (2) to compare this relationship with those developed from floras of different regions of the world; and (3) to contrast temperature predictions based on leaf margins of the native southern flora versus the naturalized alien flora, mostly of boreal origin.
Location   The temperate forest of southern South America (TFSA).
Methods   At each 1° latitudinal band, we estimated E based on species latitudinal ranges and MAT from both an isotherm map and a global temperature grid. We also calculated E from five local floras located between 40 and 43° S, and from the naturalized alien flora of Nahuel Huapi National Park in southern Argentina.
Results   We found a close relationship between E and MAT for the TFSA. Equations developed from floras of the Northern Hemisphere overestimated extant temperatures of this biome by 6–10 °C at both geographical and local spatial scales. On the other hand, MAT predictions from leaf margins of the alien flora were similar to the actual MAT. A published regression between E and MAT from tropical South America was remarkably similar to the one we estimated from the TFSA. This tropical equation predicted accurately the temperatures observed for this temperate biome based on leaf margins of the native flora.
Main conclusions   Despite massive plant extinction due to environmental cooling and biogeographical isolation during the Tertiary, leaf-margin analysis reveals that the flora of the TFSA still reflects its original development under the warmer conditions of western Gondwana and its past connections with low-latitude forest floras of tropical South America.     

Identifying and assessing the efficiency of different networks of a fine-scale hierarchy of biodiversity hotspots

Background: For prioritising practical conservation measures in areas of high endemic plant diversity, a fine-scale hierarchy of sites needs to be established. In this context, conservation sites designed at local and regional levels are considered a network of interconnected areas.

Aims: The main aim was to identify two hierarchical levels of a network of conservation sites, called ‘micro hotspots’ and ‘nano hotspots’, and test their efficiency for achieving conservation objectives across the island of Sardinia, Mediterranean Basin.

Methods: We analysed the spatial distribution of endemic vascular plant species (EVPS) richness. Additionally, the area, perimeter, connectivity and surplus costs for the protection of all endemic plant populations were used as ranking criteria for a hierarchical classification.

Results: We identified eight micro hotspots and 82 nano hotspots. Amongst the three possible solutions compared, the integrated network of micro and nano hotspots resulted in more effective conservation than any of the single-level network solutions with only micro or nano hotspots, and it included 89% of all EVPS in a relatively small areal extent.

Conclusions: The identification of hotspot networks at the regional level allowed determining priority areas to implement conservation efforts for EVPS. The integration of micro hotspots with nano hotspots resulted in the most effective network from both conservation and economic perspectives. We suggest that our model may provide an effective tool for integrated and effective conservation actions in the Mediterranean Basin.     

How much carbon is stored in the terrestrial ecosystems of the Chilean Patagonia?

We estimated the amount of carbon (C) stored in terrestrial ecosystems of the Chilean Patagonia and the proportion within protected areas. We used existing public databases that provide information on C stocks in biomass and soils. Data were analysed by ecosystem and forest type in the case of native forests. Our results show that some ecosystems have been more extensively studied both for their stocks in biomass and soils (e.g. forests) compared with others (e.g. shrublands). Forests and peatlands store the largest amount of C because of their large stocks per hectare and the large area they cover. The total amount of C stored per unit area varies from 261.7 to 432.8 Mg C ha⁻¹, depending on the published value used for soil organic C stocks in peatlands, highlighting the need to have more precise estimates of the C stored in this and other ecosystems. The mean stock in national parks (508 Mg C ha⁻¹) is almost twice the amount stored in undisturbed forests in the Amazon. State and private protected areas contain 58.9% and 2.1% of the C stock, respectively, playing a key role in protecting ecosystems in this once pristine area.     

台湾拉拉山的水青冈林及其与广西越城岭水青冈林的生态比较

水青冈林是北半球重要的森林类型之一,广泛分布在欧洲、北美和东亚的平原和山地．东亚拥有水青冈属植物种类最多,特别是在中国,但对它们研究较少,在林业上几乎还没有得到应有的利用．本文主要概略地介绍台湾拉拉山台湾水青冈林的群落学特点,并与广西越城岭的长柄水青冈林和光叶水青冈林作生态比较,为今后进一步开展水青冈林的研究提供一些参考资料．     

Conservation strategies to mitigate impacts from climate change in Amazonia

Protected area systems and conservation corridors can help mitigate the impacts of climate change on Amazonian biodiversity. We propose conservation design criteria that will help species survive in situ or adjust range distributions in response to increased drought. The first priority is to protect the western Amazon, identified as the 'Core Amazon', due to stable rainfall regimes and macro-ecological phenomena that have led to the evolution of high levels of biodiversity. Ecotones can buffer the impact from climate change because populations are genetically adapted to climate extremes, particularly seasonality, because high levels of habitat diversity are associated with edaphic variability. Future climatic tension zones should be surveyed for geomorphological features that capture rain or conserve soil moisture to identify potential refugia for humid forest species. Conservation corridors should span environmental gradients to ensure that species can shift range distributions. Riparian corridors provide protection to both terrestrial and aquatic ecosystems. Multiple potential altitudinal corridors exist in the Andes, but natural and anthropogenic bottlenecks will constrain the ability of species to shift their ranges and adapt to climate change. Planned infrastructure investments are a serious threat to the potential to consolidate corridors over the short and medium term.     

Systematics, cladistics and biogeography of the American genus Farrodes (Ephemeroptera: Leptophlebiidae: Atalophlebiinae)

Cladistic and biogeographic analyses of the genus Farrodes are presented. Two species groups are delineated within Farrodes: F. caribbianus and F. bimaculatus. Three species formerly placed in other genera– Thraulus caribbianus Traver, Thraulus roundsi Traver and Homothraulus maculatus (Needham & Murphy)–are transferred to Farrodes. The species of the F. caribbianus species group are revised. Three new species are described: F. savagei from Venezuela, F. maya and F. mexicanus from Mexico. Keys to separate the two species groups of Farrodes and the species of the F caribbianus species group are provided. Successive cladistic analyses were carried out on both adult and nymphal characters using Hennig86 and CLADOS. The matrix was composed of all available data (nymphal characters were missing for some species), from nymphal and adult stages separately and on taxa represented by both adult and nymphal characters. Species of the genera Simothraulopsis and Homothraulus (components of the Farrodes lineage) were included in the analyses, and Ecuaphkbia was used as the outgroup. Results of the four analyses are compatible. The historical biogeography of Farrodes , with a distribution from nordiern Argentina to southern Texas, is analysed using the program COMPONENT. Areas of endemism are established, and some of their relationships compared with those of other groups available in the literature.     

Nectar concentration and composition of 26 species from the temperate forest of South America

BACKGROUND AND AIMS: Floral nectar concentration and chemical composition of 26 plant species native to the temperate forest of southern South America are reported and the relationships with the flower type are evaluated. METHODS: Nectar concentration was measured with a hand refractometer and sugar composition was analysed by gas-liquid chromatography. Plant species were classified into flower type categories based not only on floral features but also on data from the literature and field observations on their pollinators. KEY RESULTS: Most data on nectar are new reports at the generic and/or specific level. Plant species in which more than one population was studied showed significant among-population variation in nectar sugar concentration and composition. Results showed a weak relationship between nectar traits and flower type. Many species had nectar containing 50 % or more sucrose (17 of 26 species), independent of the main pollinator. CONCLUSIONS: Considering that (a) nectar characteristics did not show a clear association with different flower types or with plant taxonomic membership, and (b) different populations of the same species showed large variability in sugar composition, the results suggest that other factors (e.g. historical and environmental) could be involved in determining the sugar composition of the highly endemic plant species from this region.     

Do endemic species always have a low competitive ability? A test for two Mediterranean plant species under controlled conditions

Aims Many observations concerning biological and ecological differentiation between narrow endemic and widespread congeneric plant species suggest that narrow endemic species are constrained to colonize marginal habitats because of a low tolerance to competition. Despite this topic being an important issue both for understanding evolutionary processes leading to endemism and for conservation purposes, few studies have been performed to compare competitive abilities between endemic and widespread species. Here, we present two independent experiments performed under controlled conditions using two different pairs of endemic and widespread congeneric species: Centaurea corymbosa / Centaurea maculosa and Arenaria provincialis / Arenaria serpyllifolia, both endemic species occurring in rocky calcareous habitats .Methods Mature seeds of C. corymbosa and C. maculosa were sown in pots containing ramets of the common grass, Brachypodium retusum. Pots were sorted in three treatments according to grass cover (low, intermediate and high). A control treatment (without competition) was also used. Germination, seedling survival and rosette growth were followed. For the comparisons between A. provincialis and A. serpyllifolia, seeds from natural populations were first sown without a competitor. One week after germination, healthy seedlings were transplanted in pots without Brachypodium seedling (control) or containing two Brachypodium seedlings (low competition) or four seedlings (high competition). We checked the number of capsules per individual, and we harvested the biomass after capsule maturation.Important findings Despite differences in the protocol design, results are congruent, and in both cases, endemic species are highly affected by the presence of a competitor, as are the widespread species, although we did not detect any differences between species for response to competition. The results are discussed in relation to processes leading to endemism, suggesting that the specialist model is more likely for both the study species. The present study also contributes to guidelines for the conservation of rare species in relation to landscape modification in the Mediterranean area.