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1.
The Cape Floristic Region (CFR) is one of the most plant-species-rich regions in the world. It is also a warm temperate region and hypothetically should have high gall-insect species richness, making it interesting to investigate the relationship between the insects of the region and the rich flora. The relationship between gall-insect species richness (GSR) and plant richness was investigated for the Fynbos and for representatives of vegetation of the whole CFR. Samples (of up to 600 plants per transect for Fynbos) of woody shrubs were investigated for the presence of galls. The species richness of these insects was quantified, as well as plant species richness for each transect. GSR for Fynbos was compared to global figures for GSR. Fynbos harboured significantly more gall-insect species than other CFR vegetation types. GSR was positively correlated with CFR plant richness. GSR also closely tracked plant richness in Fynbos. GSR was not significantly influenced by other variables (elevation and aspect), suggesting that plant richness per se was an important factor in generating GSR. Fynbos GSR is comparable to other sclerophyllous regions of high GSR globally, corroborating that this vegetation type is conducive to gall-insect diversification. There is likely to be a high percentage of gall-insect endemism in the Fynbos, as might be expected from the high host fidelity of this insect group. Received: 22 September 1997 / Accepted: 16 February 1998  相似文献   

2.
The Cape Floristic Region (CFR) has exceptionally high plant diversity, but because there are so few studies on insect diversity and diet breadth, little is known about the relationship between plant and insect diversity. One possibility is that plant and insect diversity in the CFR are linked through host specialisation. Alternatively, the nutrient-poor soils of the CFR may favour generalist feeding strategies with insects tracking the favourable phenophases of a variety of host plants. We studied Cephalelus, a genus of leafhoppers apparently specialised on the Restionaceae, a diverse and dominant plant family in the CFR. We examined patterns of Cephalelus host association at a single site during a 24 month field survey to determine whether Cephalelus diversity is related to the partitioning of host plant or temporal niches; or whether Cephalelus tracks the most nutritive phenophases of restios by temporal host-switching. Seven Cephalelus species were recorded which varied in their seasonal abundance patterns. The majority of these species exhibited specialised host use on different Restionaceae species, with the exception of C. pickeri. This species specialised on two host plants. The populations of two dominant species, C. pickeri and C.uncinatus, tracked the phenology of their primary host plants but not of the Restionaceae in general. To conclude; we find no evidence for host-switching or generalism in Cephalelus. Instead, they appear to be host-specialised, suggesting coupling between their diversity and that of their host plants; the Restionaceae in the CFR.  相似文献   

3.
Facilitation is a global phenomenon that occurs when one species promotes the growth, survival, or reproduction of another species, mostly in stressful environments. However, the importance of facilitation by shrubs in maintaining plant community diversity is not well evaluated in the Himalayas, especially for the richness and conservation of medicinal and human-valued species. Therefore, we aimed to explore the facilitative role of a dwarf shrub species, Berberis angulosa, in maintaining plant composition and richness of human-valued species in the Langtang valley of Nepal's Himalayas. We censused plant species in open patches and beneath Berberis during monsoon and post-monsoon (dry) seasons at three elevations.Total species richness and richness of human-valued species were significantly higher inside the Berberis canopy than in gaps; the former being 39% and the latter 46% greater under shrubs than in open sites. Facilitation by Berberis shrubs promoted plant community diversity irrespective of season and elevation; however, higher differences in mean species richness for both total plant species and human-valued species during the dry season and at high elevation indicated increased facilitation intensity under more stressful conditions. The facilitative effect of Berberis shrubs increased, combining both seasons, overall plant diversity by 19% (total=105), and human-valued species by 16% (total=56). Our results show the importance of facilitation by nurse shrubs in structuring plant communities and protecting medicinal and socio-ecologically important plants, thus enriching ecosystem services in the Himalayas. These results suggest nurse plant species should be incorporated into conservation policies and management strategies for effective biodiversity conservation and sustainability, especially in the face of climate change.  相似文献   

4.
An updated checklist is provided for the flora of Tankwa Karoo National Park, which occupies an area of 143,600 ha. A total of 730 species and 780 plant taxa (species, subspecies and varieties), representing 267 genera in 73 families, are recorded for the park. This comprises 30 bryophytes, 7 pteridophytes, 189 monocotyledons and 554 dicotyledons. Sixteen species are endemic or near-endemic to the Hantam-Tanqua-Roggeveld subregion. Twenty-eight species are of conservation concern and six species have been declared as alien invasives.  相似文献   

5.
The City of Cape Town (City) covers 2460 km2 in the southwestern corner of the Cape Floristic Region biodiversity hotspot. Established in 1654, by 1700 there were no animals larger than 50 kg within 200 km of the City. However, apart from an appreciation that timber and firewood were becoming scarce, it was only in the 1930s that the first farm near Cape Point was set aside for conservation. Table Mountain was declared a National Monument in 1958, while it was largely covered by pine and gum plantations. Conservation of the montane areas thereafter expanded, whereas the lowlands were largely ignored, except for a few bird sanctuaries. Only in 1982 was the plight of the lowlands highlighted. Although ad hoc conservation planning was undertaken subsequently, 1997 saw the first priority categorization and conservation plan. The current situation is perilous: a huge effort will be required to meet basic conservation targets for the lowland vegetation types and threatened species. Local and international partners and funders will be key to achieving this. In eight of the City's 19 national vegetation types the minimum conservation targets are not achievable. Of the 3250 plant species estimated to occur in the City, 13 are extinct and 319 are threatened according to the IUCN Red List: this is 18% of the threatened Red List species in South Africa. Now for the first time, implementation is being attempted holistically across the metropole with discussion between internal City and external stakeholders to implement the conservation plan. However, the interim plans towards achieving this — that 60% of the unproclaimed target is secured by 2014, requires that over 40 km2 be conserved per annum. This leaves 340 km2 that should be secured by 2020 when projections from City spatial growth indicate that the last critical remnants will be urbanized.  相似文献   

6.
《Flora》2007,202(4):316-327
Floristic composition, species abundance, and soil properties were studied in slope, flat and disturbed savannas in the northern part of the Gran Sabana, Venezuela. All savannas presented shallow soils (<30 cm depth) with high content of sand and low content of clay. In general, the soils were poor in nutrients and strongly acidified. The major difference between the soils was the content of the stony fraction, which was significantly higher (P<0.05) in the slope savannas than in the flat savannas. A total of 57 dicot, 42 monocot, and 7 fern species were recorded in all studied savannas. In the flat and slope savannas predominated the monocot species, while in the disturbed savanna predominated the dicots. The families with the largest number of species were Poaceae (19.8%), Cyperaceae (13.2%), Asteraceae (10.4%) and Melastomataceae (8.5%). The number of species in the flat savannas was higher than that of the slope savannas. The lowest plant species richness was associated to slope savannas and their high content of stony fraction of the soils. The highest floristic similarity was found between slope savannas, and the lowest between disturbed savanna and slope savannas. The most abundant life forms in the studied savannas were perennial (42.4%) and annual (24.5%) herbs, followed by suffruticoses (16.0%) and shrubs (12.3%), and the less frequent was lianas (4.7%). The disturbed savanna showed the higher richness and diversity index. Trachypogon plumosum (Poaceae) was the most abundant species in all studied savanna.  相似文献   

7.
Parks, as one specific type of urban open space, play important roles in the conservation of urban biodiversity and provision of recreational services for local residents. As there is a lack of specific insight into park plant species composition in relation to park features, 24 sample parks within the inner city of Beijing, the capital of China, were studied by stratified random plot sampling of their tree, shrub, and herbaceous communities, respectively, in order to investigate how human activities have influenced park green cover configuration and floristic characteristics. The quantitative correlation of species richness and the park green cover indices (patch size, shape, etc.) were studied. The importance value index for plant species (trees, shrubs, and herbaceous species) of each park was calculated. The two-way indicator species analysis approach (TWINSPAN) was applied to classify the 24 parks into different groups based on their species assemblages. Two-hundred and eighty-eight species were recorded within the 24 study parks, belonging to 184 genera and 72 families dominated by Gramineae, Compositae, and Leguminosae. Among all the recorded species, 41% are exotic. The species occurrence, abundance and diversity vary significantly among different parks. Besides the positive correlation (R=0.505, P<0.05) between herbaceous species abundance and the park green cover size, no other significant relations were found between the species abundance and other indices of park green cover configuration. Remarkably, the TWINSPAN classification resulted in a good discrimination between park functional types and the variation in their species assemblage. For the parks of similar age (development history) or landscape design, their species assemblages show more similarity. The methodology adopted and results can be employed to improve baseline information on urban plant ecology and support the setting of priorities for future park management and vegetation protection.  相似文献   

8.
This paper evaluates the history of fire management in the Bontebok National Park (3435 ha) over a period of almost four decades. A GIS database was compiled of all fires between 1972 and 2009 and the fire regime was analysed in terms of the frequency, season, size and cause of fires. Since the early 1970s, short interval burning was implemented to promote grazing for bontebok, but from 2004 the fire interval was lengthened to favour plant species diversity, an increasingly urgent conservation priority for the park. In total, 43 fires were recorded, ranging in size from 9 to 1007 ha, collectively spanning 14 013 ha. The majority of fires were large (100–500 ha), with fires of >100 ha accounting for 96% of the area burnt. The overall mean fire return period (FRP) for the park was 7.2 years, which is short judged by fynbos standards. FRPs under the old and new management regimes were 6.7 and 10.9 years respectively. Under the old regime, FRPs in renosterveld and fynbos were 5.8 and 8.0 years respectively. Large parts of the park repeatedly experienced fires at immature vegetation ages resulting in the elimination of slow-maturing seed-regenerating plant species such as Protea repens. Post-fire age distribution was highly skewed towards young vegetation, with 75% of fire-prone vegetation burning at post-fire ages of ≤7 years, and <10% of fire-prone vegetation surviving beyond 10 years of age. Prescribed and accidental fires respectively accounted for 70% and 30% of the total area burnt. Prescribed burning was mostly done in March–April, and only 8% of the total area burnt, burnt outside of the ecologically acceptable fire season. This study identified areas which have been subject to ecologically appropriate and inappropriate fire return intervals, providing a basis for informed future management and research.  相似文献   

9.
The Cape mediterranean region, part of South Africa’s Cape Floristic Realm (CFR), is recognised for its rich diversity and high degree of endemism of terrestrial vegetation. We review the biodiversity of the aquatic flora and fauna using literature sources and museum data. Geological, palaeohistorical and climate data are examined in relation to the formation of the winter-rainfall regime. Prehistoric humans had minimal impact on the aquatic biotas. Patterns and processes relating to the present-day climate, ecosystem status, distribution and diversity of plants, invertebrates and vertebrates in the CFR are reviewed. The proportion of endemic CFR species relative to the total number of species known from southern Africa is estimated. Observed distribution patterns are evaluated against temperate Gondwana vicariance, old African migrations, the role of the ancient Cape fold mountains and Pangaea. The lack of Pleistocene glaciations in Africa, the oligotrophic nature of the river systems and the palaeohistorical origin and distribution of taxa are considered when assessing reasons for disjunct distribution patterns. Impacts of anthropogenic interference with aquatic ecosystems are evaluated. Fragmented jurisdiction of nature conservation authorities is seen as a problem for attaining adequate conservation of CFR aquatic ecosystems. Systematic conservation planning is under way for the region.  相似文献   

10.
Phylogenetic diversity and ecological features in the Egyptian flora   总被引:6,自引:0,他引:6  
Until fairly recently, regional-scale ecological and evolutionarypatterns have tended to be ignored as conservation efforts have been concernedwith species and their habitats. Here we compare frequencies in the Egyptianflora of particular rank sizes (order, family and genus) with patterns ofspecies abundance (classified as very rare, rare, common, or very common) and anarray of life-history attributes. The angiosperm flora of Egypt is representedby 2446 taxa (2088 species), including taxa in 10 subclasses, 51 orders, 120families, and 742 genera. A high degree of monotypism was observed: four ordersare monotypic (each existing as single species), and have very rare overallabundances; 30 families are monotypic (17 of which are very rare or rare); and 354genera are monotypic (over 70% of which are very rare or rare). Fourteenfamilies (in particular the Resedaceae and Zygophyllaceae) have at leastone-fifth of their global species represented in the Egyptian flora. Introducedspecies in general, and tree, aquatic herb and liana life forms all are especially well represented among monotypic genera. Native taxa are highlyrepresented among rare and very rare abundance classes, while introduced taxadid not differ significantly in their abundance patterns, compared to overallflora values. Few large genera (>20 spp.) occur in the flora, with mostspecies concentrated in genera containing 8–19 species per genus.Similarly, few families were highly speciose. Annual and herbaceous species weresignificantly over-represented, mainly among large, speciose genera andfamilies. However, perennials, trees, shrubs, aquatic herbs, lianas and parasiticspecies were found mainly in families and genera having very few taxa.Life-history attributes may have important implications to speciation rates.Taxonomically based results, involving abundances and life-history attributes,are discussed in the context of biodiversity and conservation.  相似文献   

11.
Floristic inventory of wild plants comprised of total 129 plant species belonging to 42 families and 101 genera. Location wise UAP contributed greater amount of plant species (53%), followed by PFI (29%), UoP (15%) and Islamia College (3%). Majority of the plants were annual herbs (58%), followed by perennial herbs (29%), trees (10%) and shrubs (3%), respectively. The leading families included Poaceae, contributed 18% of all the plant species. Habitat wise, 44% of them grew in grassy plains, abandoned lands and mismanaged lawns, followed by roadsides (34%), undulating grassy plains (15%) and stony grounds with uneven topography along with stream banks and drainage ditches (7%). Still some of plant species were used as ornamentals, while some shrubs were use in fencing around fields; others were utilized as green manure, for fishing, sheltering and religious purposes. Exploring and identifying the wild flora of the campus and compiling as a handbook would help to monitor new plants introductions particularly of noxious invasive weeds in the campuses in future.  相似文献   

12.
Aim Vicariance has played a major role in the evolution of the southern rock agama, Agama atra (Reptilia: Agamidae), and it is hypothesized that habitat shifts will affect small‐scale patterns of gene flow. The Cape Floristic Region (CFR) is known for high levels of diversity and endemism; thus we set out to investigate whether genetic structuring of CFR populations of A. atra corresponds to regional environmental shifts. Location Cape Fold Mountains and the Cape Floristic Region of South Africa. Methods The phylogeographical structure of 116 individuals of A. atra was determined by making use of 988 characters derived from two mitochondrial DNA fragments (control region and the NADH dehydrogenase subunit 2 coding region, ND2). Most animals originated from the CFR, but to gain a better understanding of the processes and patterns of dispersal within the species, 17 additional specimens from outside the CFR were also included and analysed in a phylogenetic context. Results Parsimony and Bayesian analyses revealed four distinct CFR clades (Cape clades) associated with geography. Phylogenetic analyses suggest that populations of A. atra in the CFR region are not entirely isolated from other populations, because some individuals from outside the CFR were nested within the four main Cape clades. The combined mitochondrial DNA data set revealed 59 distinct haplotypes in the CFR. Analysis of molecular variance (amova ) confirmed the high degree of genetic structure among the Cape clades, with more than 75% of the genetic variation found among the geographical areas. A spatial amova suggested that a ‘central clade’ originally defined as one of the four Cape clades may contain several additional populations. The main cladogenesis of A. atra within the CFR is estimated to have taken place c. 0.64–2.36 Ma. Main conclusions Agama atra shows at least four distinct genetic provinces within the CFR region, which highlights the conservation importance of this biologically diverse area. The dates of separation among the clades coincide well with the documented Pleistocene climate fluctuations, which might have contributed towards the isolation among lineages; the congruent genetic structure of A. atra with other CFR taxa further supports vicariance as a main isolating factor.  相似文献   

13.
In comparison with other Macaronesian Islands (e.g., the Canary Islands), the Cape Verde Islands have received little attention in terms of plant molecular phylogenetic studies, which might also elucidate the general floristic history of this archipelago. The Cape Verdean vascular plant flora (ca. 12% endemics) has traditionally been regarded as relict of a former subtropical Tertiary flora. In contrast, it has been postulated more recently that the flora is much younger and of Pleistocene origin. To test these hypotheses, we have produced molecular phylogenies associated with a molecular clock approach, sampling all nine Cape Verdean endemic Diplotaxis taxa and 21 accessions representing the D. harra complex from across its distributional range. Analyzing three molecular markers from the nuclear and chloroplast genome, we provide evidence that the Cape Verdean endemic Diplotaxis originated from North African D. harra populations in Pleistocene times, putatively linked to the genesis of the (western) Sahara. This adds to the emerging picture that the present Cape Verdean flora is of Pleistocene origin.  相似文献   

14.
Phylogenetic patterns, adaptations and conservation status of the rare species flora of a winter–summer rainfall ecotone in southern Africa were investigated to shed light on the species' evolutionary history and conservation requirements. Some 11% (93 species) of the Greater Fish River Canyon Landscape in Namibia were classified as rare species, more than half currently not receiving formal protection in Namibia. The rare species flora does not present a subset of the overall species pool, but a unique assemblage of plant species, over‐represented by members of the family Mesembryanthemaceae, Crassulaceae, Asphodelaceae and Hyacinthaceae. Low growth forms (dwarf leaf‐succulent shrubs, dwarf stem succulents and dwarf deciduous shrubs) as well as bulbs are more common amongst rare species. Multiple factors and processes, likely interlinked, are believed to be responsible for determining the rare species flora, indicating that individual species respond differently to the challenges posed by this arid environment. Some plants are likely remnants of wetter conditions in the past, which have retained viable populations in the mountainous terrain of this landscape, others may have evolved in situ.  相似文献   

15.
B-type natriuretic peptide (BNP) is a diagnostic and prognostic tool in heart failure and also in Chagas disease, which is caused by the protozoan Trypanosoma cruzi and has cardiomyopathy as a main feature. BNP lipolytic actions and T. cruzi infection in the adipose tissue have been recently described. We aim to investigate the relationship between BNP and anthropometric measures and whether it is influenced by T. cruzi infection. We measured BNP, body mass index (BMI), waist circumference (WC), triceps skin-fold thickness (TSF) and performed serological, biochemical and electrocardiographic exams in 1398 subjects (37.5% infected with T. cruzi) in a community-dwelling elderly population in Bambui city, Brazil. Linear multivariate regression analysis was performed to investigate determinants of BNP levels. BNP levels were significantly (p < 0.05) higher in T. cruzi-infected subjects than in the non-infected group (median = 121 and 64 pg/mL, respectively). BMI, WC and TSF in infected subjects were significantly lower than those in non-infected subjects (24.3 vs. 25.5 kg/m2; 89.2 vs. 92.4 cm; and 14.5 vs. 16.0 mm, respectively). There was an inverse relationship between BNP levels and BMI (b = −0.018), WC (b = −0.005) and TSF (b = −0.193) levels. Infected and non-infected groups showed similar inverse relationships between BNP and BMI (b = −0.021 and b = −0.015, respectively). In conclusion, there was an inverse relationship between BNP levels and the anthropometric measures. Despite the actions in the adipose tissue, T. cruzi infection did not modify the associations between BNP and BMI, suggesting that body mass does not modify the accuracy of BNP in Chagas disease.  相似文献   

16.
Fynbos is a vegetation type in the Cape Floral Region (CFR), at the southern tip of Africa. Portions of the CFR are recognised as a ‘serial’ World Heritage site and acclaimed by UNESCO as the world’s ‘hottest hot spot’ for plant species richness and endemism. Habitat degradation and species losses through human intrusion in the CFR include transformations brought about by introduced invasive alien tree species. Since 1970, ten invasive tree species in the fynbos biome have been subjected to biological control, namely: six Acacia species and Paraserianthes lophantha (Mimosaceae), Hakea sericea (Proteaceae) and Leptospermum laevigatum (Myrtaceae), all from Australia, and Sesbania punicea (Fabaceae) from South America. A total of 19 species have been deployed as biological control agents, including nine weevil species (eight Curculionidae and one species in the family Brentidae: Apioninae), a seed-feeding moth species (Lepidoptera: Carposinidae), two species of bud-gallers (Hymenoptera: Pteromalidae), two species of flower-gallers (Diptera: Cecidomyiidae), and a gall-forming rust fungus (Uredinales: Pileolariaceae). Most of these agents primarily reduce seed production, directly or indirectly, but some also cause die-back and mortality of their host plants. The overall result, often in combination with mechanical clearing and herbicide applications, has been a substantial decline in the abundance and/or aggressiveness of most of the targeted host-plants. In this review, four representative but contrasting case studies are used to show that biological control is an indispensible supplement to other management practices for long-term conservation of the remnants of the fynbos biome.  相似文献   

17.
The Addo Elephant National Park in the warm-temperate Eastern Cape was proclaimed in 1931 to protect one of the four elephant populations in South Africa which survived into the present century. However, since the late 1970s, a major objective of the Park is to protect intact a viable example of succulent thicket – the regional ecosystem. Succulent thicket is endemic to the Eastern Cape and forms the major component of the Albany Centre, a floristic region of high diversity and endemism, especially among succulent shrubs and geophytes. This ecosystem is poorly represented in the reserve system and is highly threatened by overgrazing and clearing for agriculture. Under the present stocking rate of more than two elephants/km2, succulent thicket in the Park has been severely impacted: in particular, biomass, stature and plant diversity have been reduced. We show that the flora of the Park is of great regional significance. Of a total of 581 species, 12.4% were classified as regional endemics and/or Red Data Book species (collectively termed 'species of special concern), and 32.2% were not known to be conserved in any other succulent thicket protected area. Relative to the remainder of the flora, both categories of species were over-represented among succulent shrubs (predominantly Euphorbiaceae and Mesembryanthemaceae) and geophytes (predominantly Asphodelaceae and Hyacinthaceae). This taxonomic and biological profile coincides with that of species vulnerable to local extinction as a result of elephant impacts. The Park authorities will need to find a solution to the conflict between maintaining a large population of megaherbivores, and maintaining the structure and diversity of succulent thicket.  相似文献   

18.
This study describes diversity patterns in the flora of the Campo-Ma’an rain forest, in south Cameroon. In this area, the structure and composition of the forests change progressively from the coastal forest on sandy shorelines through the lowland evergreen forest rich in Caesalpinioideae with Calpocalyx heitzii and Sacoglottis gabonensis, to the submontane forest at higher elevations and the mixed evergreen and semi-deciduous forest in the drier Ma’an area. We tested whether there is a correlation between tree species diversity and diversity of other growth forms such as shrubs, herbs, and lianas in order to understand if, in the context of African tropical rain forest, tree species diversity mirrors the diversity of other life forms or strata. Are forests that are rich in tree species also rich in other life forms? To answer this question, we analysed the family and species level floristic richness and diversity of the various growth forms and forest strata within 145 plots recorded in 6 main vegetation types. A comparison of the diversity within forest layers and within growth forms was done using General Linear Models. The results showed that tree species accounted for 46% of the total number of vascular plant species with DBH ≥1 cm, shrubs/small trees 39%, climbers 14% and herbs less than 1%. Only 22% of the diversity of shrubs and lianas could be explained by the diversity of large and medium sized trees, and less than 1% of herb diversity was explained by tree diversity. The shrub layer was by far the most species rich, with both a higher number of species per plot, and a higher Shannon diversity index, than the tree and the herb layer. More than 82% of tree species, 90% of shrubs, 78% of lianas and 70% of herbaceous species were recorded in the shrub layer. Moreover, shrubs contributed for 38% of the 114 strict and narrow endemic plant species recorded in the area, herbs 29%, trees only 20% and climbers 11%. These results indicate that the diversity of trees might not always reflect the overall diversity of the forest in the Campo-Ma’an area, and therefore it may not be a good indicator for the diversity of shrubs and herbaceous species. Furthermore, this suggests that biodiversity surveys based solely on large and medium sized tree species (DBH ≥0cm) are not an adequate method for the assessment of plant diversity because other growth form such as shrubs, climbers and herbs are under-represented. Therefore, inventory design based on small plots of 0.1 ha, in which all vascular plants with DBH ≥1 cm are recorded, is a more appropriate sampling method for biodiversity assessments than surveys based solely on large and medium sized tree species.  相似文献   

19.
The wide knowledge gaps in invasion biology research that exist in the developing world are crucial impediments to the scientific management and global policymaking on biological invasions. In an effort to fill such knowledge gaps, we present here an inventory of the alien flora of India, based on systematic reviews and rigorous analyses of research studies (ca. 190) published over the last 120 years (1890–2010 AD), and updated with field records of the last two decades. Currently, the inventory comprises of 1,599 species, belonging to 842 genera in 161 families, and constitutes 8.5% of the total Indian vascular flora. The three most species-rich families are Asteraceae (134 spp.), Papilionaceae (114 spp.) and Poaceae (106 spp.), and the three largest genera are Eucalyptus (25 spp.), Ipomoea (22 spp.), and Senna (21 spp.). The majority of these species (812) have no report of escaping from cultivation. Of the remaining subset of 787 species, which have either escaped from intentional cultivation, or spread after unintentional introduction, casuals are represented by 57 spp., casual/naturalised by 114 spp., naturalised by 257 spp., naturalised/invasive by 134 spp., and invasive by 225 spp. Biogeographically, more than one-third (35%) of the alien flora in India has its native ranges in South America, followed by Asia (21%), Africa (20%), Europe (11%), Australia (8%), North America (4%); and cryptogenic (1%). The inventory is expected to serve as the scientific baseline on plant invasions in India, with implications for conservation of global biodiversity.  相似文献   

20.
We review the conservation status and threats to the endemic vascular flora of the Cape Verde islands, mostly based on the past two decades of collecting, literature review and herbarium specimens. The application of IUCN Red List criteria and categories using RAMAS software reveals that 78% of the endemic plants are threatened (29.3% Critically Endangered, 41.3% Endangered, 7.6% Vulnerable). Most of these endemics have a limited geographical range, and half of them have Areas of Occupancy and Extents of Occurrence of < 20 and 200 km2, respectively. Our data show that, over the last two decades, the Cape Verde vascular plants have become more threatened and their conservation status has declined, mostly as a consequence of the increase in exotic species, habitat degradation and human disturbance. This paper presents the first comprehensive IUCN Red List data review for the plants endemic to Cape Verde, thus providing an important step towards the recognition and conservation of its threatened endemic flora at the national and global level. It also fills a knowledge gap, as it represents the first thorough assessment of the conservation status of the entire endemic flora of a Macaronesian archipelago.  相似文献   

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