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1.
The coastal lowlands of the Western Cape (CLWC) form part of the fynbos biome, an area renowned for its high levels of plant diversity and endemism. The vegetation of the CLWC has been severely reduced and fragmented, and is currently impacted on by agricultural, pastoral, coastal resort and urban development, as well as alien plant spread. Furthermore, most of the vegetation communities are under-represented within existing protected areas. In response to this urgent need for increased conservation efforts, an initiative to establish a UNESCO-MAB biosphere reserve in the area has been launched. The aim of this project was to use biological criteria to identify areas that could potentially contain the core areas and buffer zones of a biosphere reserve. A reserve selection algorithm was chosen which provides a flexible tool for selecting representative areas for protection. The algorithm is a step-wise heuristic, which has rules for including mandatory polygons, forcing adjacency, including desirable (e.g. Red Data Book plant species) and excluding undesirable features (e.g. bisection by major roads). Farm boundaries (cadastral units) were used as selection units, resulting in a total of 1717 parcels. The selection process was conducted three times with target areas set at 10%, 25% and 50% of the original extent of each vegetation type within the study area. Areas of 62834 ha, 121199 ha and 242397 ha, respectively, or 36% 49% and 76% of the available land in the study area being selected. It is recommended that the area identified as the 50% target area be considered the future site of core areas and buffer zones for the proposed biosphere reserve. The algorithm successfully maintained a high degree of connectivity between selected areas. This is important considering the high levels of plant beta diversity associated with edaphic gradients. Rather than presenting a definitive reserve system, this study provides a tool allowing biological criteria to be included explicitly within the negotiation process. As the biosphere reserve is assembled, priorities can be re-assessed.  相似文献   

2.
We discuss the possible links between the fossil record of marine biodiversity, nutrient availability and primary productivity. The parallelism of the fossil records of marine phytoplankton and faunal biodiversity implicates the quantity (primary productivity) and quality (stoichiometry) of phytoplankton as being critical to the diversification of the marine biosphere through the Phanerozoic. The relatively subdued marine biodiversity of the Palaeozoic corresponds to a time of relatively low macronutrient availability and poor food quality of the phytoplankton as opposed to the diversification of the Modern Fauna through the Mesozoic–Cenozoic. Increasing nutrient runoff to the oceans through the Phanerozoic resulted from orogeny, the emplacement of Large Igneous Provinces (LIPs), the evolution of deep-rooting forests and the appearance of more easily decomposable terrestrial organic matter that enhanced weathering. Positive feedback by bioturbation of an expanding benthos played a critical role in evolving biogeochemical cycles by linking the oxidation of dead organic matter and the recycling of nutrients back to the water column where they could be re-utilized. We assess our conclusions against a recently published biogeochemical model for geological time-scales. Major peaks of marine diversity often occur near rising or peak fluxes of silica, phosphorus and dissolved reactive oceanic phosphorus; either major or minor 87Sr/86Sr peaks; and frequently in the vicinity of major (Circum-Atlantic Magmatic Province) and minor volcanic events, some of which are associated with Oceanic Anoxic Events. These processes appear to be scale-dependent in that they lie on a continuum between biodiversification on macroevolutionary scales of geological time and mass extinction.  相似文献   

3.
A screening was carried out on 69 fungal strains isolated from alkaline-calcareous, neutral and alkaline-sodic soils, as well as from their associated plant material, to determine their ability to grow at alkaline pH. A total of 32 fungi were selected for their ability to produce alkaline keratinase activity in submerged shaken cultures supplemented with soybean meal (SM) and tryptone and on cow hair (CH) under solid state fermentation conditions. Although several fungal strains produced keratinolytic activity on both SM and CH, they differed in the levels detected. Among them, Aspergillus niger, Cladosporium cladosporioides, Metarrhizium anisopliae, Neurospora tetrasperma and Westerdikella dispersa were the best producers, with levels higher than 1.2 U ml−1. Different fungal species are here reported for the first time for their ability to produce keratinolytic activity at alkaline pH.  相似文献   

4.
Sustainability is said to be the science of integration, be it integration of scale, discipline or of stakeholders’ interests. One way to integrate such diverse elements is to develop sustainable development indicators. Numerous national and international organizations have attempted to develop such indicators, among which interaction indicators are of critical importance because they enable us to link up human activities, ecological dynamics, and social goals. Among the various ways to develop such indicators, the most common ones are the pressure–state–response (PSR) indicators, as well as others coming from this framework. With realistic methodology one shall observe how PSR indicators might appear as an operational tool to face rapid social and ecological changes within a French biosphere reserve in Brittany. Results suggest that such a framework is insufficient to describe, understand and manage social and ecological interactions.
Harold LevrelEmail:
  相似文献   

5.
In just 20 years, the field of biosphere-atmosphere interactions has gone from a nascent discipline to a central area of modern climate change research. The development of terrestrial biosphere models that predict the responses of ecosystems to climate and increasing CO2 levels has highlighted several mechanisms by which changes in ecosystem composition and function might alter regional and global climate. However, results from empirical studies suggest that ecosystem responses can differ markedly from the predictions of terrestrial biosphere models. As I discuss here, the challenge now is to connect terrestrial biosphere models to empirical ecosystem measurements. Only by systematically evaluating the predictions of terrestrial biosphere models against suites of ecosystem observations and experiments measurements will a true predictive science of the biosphere be achieved.  相似文献   

6.
Previous studies have demonstrated that during lower-body exercise the percentage of heart rate reserve (%HRR) is equivalent to the percentage of the oxygen consumption reserve (%V˙O(2R)) but not to a percentage of the peak oxygen consumption (%V˙O(2peak)). The current study examined these relationships in trained surfboard riders (surfers) during upper-body exercise. Thirteen well-trained competitive surfers performed a stepwise, incremental, prone arm-paddling exercise test to exhaustion. For each subject, data obtained at the end of each stage (i.e., HR and V˙O(2) values) were expressed as a percentage of HRR, V˙O(2peak), and V˙O(2R) respectively and used to determine the individual %HRR-%V˙O(2peak) and %HRR-%V˙O(2R) relationships. Mean slope and intercept were calculated and compared with the line of identity (slope=1, intercept=0). The %HRR versus %V˙O(2R) regression mean slope (0.88±0.06) and intercept (20.82±4.57) were significantly different (p<0.05) from 1 and 0, respectively. Similarly, the regression of %HRR versus %V˙O(2peak) resulted in a line that differed in the slope (p<0.05) but not in the intercept (p=0.94) from the line of identity. Predicted values of %HRR were significantly higher (p<0.05) from indicated values of %V˙O(2R) for all the intensities ranging from 35% to 95% V˙O(2R). Unlike results found for lower-body exercise, a given %HRR during prone upper-body exercise was not equivalent to its corresponding %V˙O(2R). Thus, to ensure more targeted exercise intensity during arm-paddling exercise, individual HR-V˙O(2) equations should be used.  相似文献   

7.
Migration pathways of butterflies in Southeast Altai (the core of the Transboundary biosphere territory “Altai”) in the spring and summer seasons of 1990 and over the period of 1995–2006 were analyzed. The density of the population was assessed, and specific features of the butterfly distribution among four high-altitude belts (alpine tundra, subalpine, forest, and steppe) were revealed. Eighty-five habitats were examined and butterfly migration pathways were recorded for 359 hours of route surveys with a total length of 875 km. More than 16.5 thousand individuals belonging to 6 families, 66 genera and 107 species were recorded. The total species abundance of butterflies was found to be maximal in the forest belt; the highest population density was recorded in the alpine-tundra belt. The results obtained indicate that the basic differences among the butterfly populations are determined by the thermal conditions related to the altitude and, to a lesser degree, the degree of forestation. The distribution of most butterfly species over the transboundary territory is primarily determined by the recent environmental conditions, in particular the aridity of the tundra-steppe belt.  相似文献   

8.
We compared the location of anuran site records with the protected area network of Australia. We determined how many sites fell within protected areas (PAs) and assessed whether the available distribution of record sites matched that which could be expected by random chance. We also determined the number of PAs that each species was located in and how many were larger (>1,000 ha) PAs. A total of 25,961 from 96,947 record sites (26.78%) for 211 anuran species fell within 1 of 7,416 International Union for the Conservation of Nature (IUCN) criteria “reserves” that protect 7,689,024 ha (10.54%) of mainland Australia. One hundred and sixty-nine species represented by >30 records had a mean 30.05% of record sites within PAs, with 36 species having >45% of record sites in PAs and 18 species <10% of record sites within PAs. Highly “reserved” species are typically montane, prefer rainforest, and have small distributional ranges. Poorly “reserved” species either occur in northern Australia or within highly productive and poorly protected agricultural lands of eastern and western Australia. Several species from coastal eastern Australia have relatively high proportions of record sites within PAs (e.g., Litoria olongburensis and Uperoleia tyleri), even though they are generally believed to be threatened by habitat loss. The number of records available for each species was related to the area of occupancy and the length of calling season, but not to the relative frequency of calling activity. The number of record sites in reserves was greater than expected by chance and most species of frogs are found in many reserves. Species dependent on native vegetation that are prevalent in agricultural areas represent the most pressing issue, as there is already low reservation of such habitats and the remaining native vegetation continues to be cleared.  相似文献   

9.
<正>Dear Editor,Mayer-Rokitansky-Küster-Hauser(MRKH) syndrome is a rare congenital disease characterized by the hypoplastic uterus and vagina in women with a normal female karyotype(46, XX) and phenotype. Although some genes and mutations, such as WNT4, have been reported in a small portion of MRKH syndrome patients(Biason-Lauber et al.,  相似文献   

10.
A three-year mycological investigation of the Kékes North forest reserve in the Mátra mountains. Hungary proved the richness of the area in lignicolous macrofungi. Diversity of macrofungi was in close correlation with the developmental phases of the forest as well as with the amount of dead wood of different quality (diameter, stage of decomposition, etc.).  相似文献   

11.
This paper presents the results of long-term research regarding the algal biodiversity of the Sikhote-Alin biosphere reserve, Primorsky region (Russian Far East). The algal flora is compised of 675 species represented by 839 subspecific taxa from seven divisions: Cyanophyta, 77 (91 including subspecific taxa); Euglenophyta, 18 (21); Chlorophyta, 84 (86); Streptophyta, 137 (169); Rhodophyta, 3; Ochrophyta, 355 (468): Diatomophyceae, 331 (444), Chrysophyceae, 6, Xanthophyceae, 16, Phaeophyceae, 2; Dinophyta, 1. The algal floras of ecologically different reserve water bodies are described, including the brackish, Blagodatnoe Lake, the shallow freshwater Golubichnoe Lake, the alpine Solontsovskie Lakes, the rapid cold-water Serebryanka and Dzhigitovka rivers, and the lowland Kolumbe River. The taxonomic composition of the algal flora has been analysed. Differences between the algal communities of lakes and rivers are described and rare species are noted. The algal flora of the Sikhote-Alin biosphere reserve is currently the richest and most diverse of the six reserves studied in the Primorsky region.  相似文献   

12.
Increasingly, biogeographical knowledge and analysis are playing a fundamental role in assessing the representativeness of biodiversity in protected areas, and in identifying critical areas for conservation. With almost 20% of the country assigned to protected areas, Chile is well above the conservation target (i.e. 10–12%) proposed by many international conservation organizations. Moreover, the Chilean government has recently proposed new conservation priority sites to improve the current protected area network. Here, we used all 653 terrestrial vertebrate species present in continental Chile to assess the performance of the existing and proposed reserve networks. Using geographical information systems, we overlaid maps of species distribution, current protected areas, and proposed conservation priority sites to assess how well each species is represented within these networks. Additionally, we performed a systematic reserve selection procedure to identify alternative conservation areas for expanding the current reserve system. Our results show that over 13% of the species are not covered by any existing protected area, and that 73% of Chilean vertebrate species can be considered partial gaps, with only a small fraction of their geographical ranges currently under protection. The coverage is also deficient for endemic (species confined to Chile) and threatened species. While the proposed priority sites do increase coverage, we found that there are still several gaps and these are not the most efficient choices. Both the gap analysis and the reserve selection analysis identified important areas to be added to the existing reserve system, mostly in northern and central Chile. This study underscores the need for a systematic conservation planning approach to redefine the conservation priority sites in order to maximize the representation of species, particularly endemic and threatened species.  相似文献   

13.
The dung incorporation activity of three species of coprophagous beetle macrofauna (Coleoptera: Scarabaeidae: Scarabaeinae), Dichotomius colonicus (Say), Phanaeus quadridens (Say), and Copris klugi sierrensis Matthews, was studied on a hectare of pastureland on "La Michilía" Biosphere Reserve. In total, 223 specimens of the three species were recorded. On the basis of abundance, the dominant species was D. colonicus. A substantial percentage (31% in September and 51% in October) of dung pats remained on the surface, untouched by beetles. Most of the specimens observed (92%) were found amassing dung in galleries. The dung accumulation capacity of D. colonicus varied from 5 to 135 g of dung (dry weight)/pair, whereas C. klugi sierrensis amassed an average of 24.3 +/- 8.5 g/pair and P. quadridens amassed an average of 12 +/- 2.5 g/pair. Based on dung burying efficiency, D. colonicus was considered the most beneficial of the three species in the study area. It dug deeper, wider galleries and incorporated the largest amount of dung into the soil.  相似文献   

14.
15.
To provide more information about whether sharks benefit from no-take marine reserves, we quantified the relative abundance and biomass of reef sharks inside and outside of Namena, Fiji’s largest reserve (60.6 km2). Using stereo baited remote underwater video systems (stereo-BRUVs), we found that the abundance and biomass of sharks was approximately two and four times greater in shallow and deep locations, respectively, within the Namena reserve compared to adjacent fished areas. The greater abundance and biomass of reef sharks inside Namena is likely a result of greater prey availability rather than protection from fishing. This study demonstrates that marine reserves can benefit sharks.  相似文献   

16.
Conservation of valuable populations must be based on a thorough understanding of their genetic variation, especially for species negatively affected by human activities. We investigated the population of larch from the nature reserve in the Gorce Mountains, which was established to preserve a unique stand of Larix decidua subsp. polonica, a remnant of one of the largest native complexes of this species. The chloroplast marker ll-TaqI was used to investigate whether the gene pool of the analysed population was contaminated with the alien larch species. We used eleven nuclear DNA microsatellite markers (nSSRs) to examine this population’s genetic diversity and verify the hypothesis about historical use of the larch from the reserve as a source of reproductive material for the Tatra Mountains. The link between the reserve population and the European larch’s ancestral groups was also verified. No contamination of the studied pool of individuals by alien species was found. The study showed high genetic variability in larch from the Gorce Mountains (HE = 0.689, HO = 0.671). The differentiation between the Gorce and Tatra National Park populations was FST = 0.038 (p < 0.001). Trees from the reserve and the national park formed two distinct genetic groups. We rejected the hypothesis that the nature reserve was the source of the regeneration material used in the Tatra Mountains. The study proved the uniqueness of the reserve population, and confirmed the appropriateness of the protection measures taken.  相似文献   

17.
Of the twelve species ofChamaedorea palm recorded for Belize, three are of international economic value because their cut leaves (xaté) are traded in the floricultural industry. Traditionally, Belize has not harvested xaté, the industry being based in Mexico and Guatemala. However, a decline in wild xaté stocks in these countries means Guatemalan leaf harvesters now illegally harvest xaté in Belize. To assess the local abundance of the BelizeanChamaedorea resource, its economic value, and the extent to which it has been illegally harvested, 209 plots measuring 20 meters (m) by 20 m were established in the Greater Maya Mountains (GMM) in western Belize, which includes the Chiquibul Forest Reserve (CFR). We estimate that 37.8 million leaves with a value of U.S. 0.3 million to xateros have been extracted from the CFR. The standing export value is calculated as U.S.0.3 million to xateros have been extracted from the CFR. The standing export value is calculated as U.S. 1.8 million for the CFR and U.S. $5 million for the GMM.  相似文献   

18.
19.
The alpha-1,4-glucan phosphorylase (alpha-1,4-glucan: orthophosphate glucosyltransferase; EC 2.4.1.1) associated with the particulate cell fraction of Streptococcus mitior strain S3 was compared with the soluble maltodextrin phosphorylase that had been previously isolated from the same organism (Walker et al., 1969). The particulate enzyme was more sensitive to the glycogen content of the cell than the soluble euzyme; its activity was highest when the cells were grown under conditions favoring high glycogen storage. Substrate specificities of the two high activity towards endogenous glycogen, whereas low-molecular-weight maltodextrins were the preferred substrates for the soluble phosphorylase. The purification of the particulate phosphorylase included incubation of the particulate fraction in 160 mM sodium phosphate-10 mM sodium citrate-0.1% (wt/vol) Triton X-100 buffer (pH 6.7) and ion-exchange chromatography on diethylamino-ethyl- Sephadex A-50. The purified enzyme was fully soluble. The value for the purification factor was variable and depended on (i) the substrate used and (ii) whether the synthetic or the degradative reaction was being measured. The solubilization resulted in considerable changes in the properties of the phosphorylase: the pH optimum for activity was raised from 6.0 to 7.0-7.5 and the substrate specificity was altered. Consequently, the purified enzyme bore greater similarity to the soluble maltodextrin phosphorylase. The reported results are best explained in terms of a single phosphorylase, the specificity which is determind by its binding state in the cell. The enzyme acts as a glycogen phosphorylase in the particulate state and as a maltodextrin phosphorylase when soluble. The equilibrium between the two forms is related to the glycogen content of the cells.  相似文献   

20.
A phytosociological survey was carried out in the Forest Genetic Reserve of Caçador, which belongs to the Brazilian Agriculture Research Corporation – EMBRAPA. The Genetic Reserve comprises an area of 1120 ha and has been managed by the Agricultural Research and Extension Corporation of the State of Santa Catarina (EPAGRI). A restricted random sampling by plots, with units of 2500 m2 (100 x 25 m) was used, allocating 40 plots to stands containing Araucaria angustifolia. All trees with diameter 20 cm at breast height were measured. Frequency, density, dominance, soil coverage, and importance value were evaluated, The most important species indicated by these parameters were Araucaria angustifolia, Ocotea porosa, Cupania vernalis, Matayba eleagnoides, Mollinedia elegans, Ocotea pulchella, Ilex paraguariensis and Prunus brasiliensis. In spite of the very high mean basal area (35.84 m2 ha-1), mean density (222 trees ha-1) and mean volume outside bark (531.14 m3 ha-1) for A. angustifolia it was found that understory had low commercial value and a very low natural regeneration rate in the priority species for in situ conservation: A. angustifolia, Cedrela fissilis, I. paraguariensis, Mimosa scabrella, P. brasiliensis and O. porosa. Simpson's index has shown in this case a low floristic diversity of species however, as was expected, the highest levels of abundance, dominance and frequency were found for Araucaria angustifolia.  相似文献   

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