35,147 research outputs found
Bryophyte flora of Western Melanesia
A project dealing with the hepatic and moss floras of New Guinea and the Solomon Islands has proceeded more than halfway. The revision of the flora is based on the study of ca 17000 specimens collected in 1981. Two new genera and ca 50 new species have been described in 33 published papers and seven manuscripts. Many families, genera and species not previously recorded for the area have been added to the flora. More than 300 names have been reduced to synonyms. The percentage of endemic species of liverworts (40 %) is higher than that of mosses (18 %). Most of the endemic species occur at elevations above 1700 m. The geological history of New Guinea suggests that these high altitude endemics may be relatively young, i.e. less than 10 million years old. The moss flora is more closely related to the floras of Indonesia and the Philippines and continental Asia than to that of Australia. This can be explained by plate tectonics. The altitudinal distribution of hepatic and moss floras partly coincides with the zonation of vegetation proposed earlier. Human influence on bryophyte floras is devastating but a part of the flora may survive in gardens and plantations
Four rural cemeteries in central western NSW: Islands of Australiana in a European sea?
Vascular plants present in groundstoreys of variously–managed areas in four cemeteries in central western NSW – two on the Central Western Slopes (Garra and Toogong) and two on the Central Tablelands (Lyndhurst and Carcoar) – were recorded over periods of 6–10 years. It was hypothesised that (a) areas of the cemeteries with a history of nil or low disturbance would represent high quality remnant vegetation (i.e. contain a diversity of native species but few naturalised species), and (b) that clearing of woody vegetation, together with similar management (e.g. regular mowing) would result in homogenisation of the groundstoreys such that many species, native and naturalised, would be common to all sites. 344 species (176 native, 154 naturalised and 14 non–naturalised exotics) were recorded across the four cemeteries. Many native species that were rare in the surrounding agricultural lands were present in the cemeteries (enhancing their value as conservation areas) but no cemetery contained areas of groundstorey that would qualify as ‘pristine’. Across all management areas, the proportions of naturalised species in the native + naturalised floras of the cemeteries ranged from 46 to 55 %. Though never dominant, naturalised species also comprised high proportions (42 to 51 %) of the floras of the least disturbed (nil or infrequently mown) areas within each cemetery. Many (40 %) of the species recorded occurred at only one cemetery. This partly explained why the floras of similarly– managed parts of cemeteries on the Central Western Slopes were, contrary to expectations, markedly different to those on the Central Tablelands. However, within the same botanic subdivision, floras – particularly of naturalised species in regularly mown grasslands – were more similar (‘homogenised’) than those of nil or infrequently mown grasslands
Floristic response to urbanization: Filtering of the bioregional flora in Indianapolis, Indiana, USA
PREMISE OF THE STUDY: Globally, urban plant populations are becoming increasingly important, as these plants play a vital role in ameliorating effects of ecosystem disturbance and climate change. Urban environments act as filters to bioregional flora, presenting survival challenges to spontaneous plants. Yet, because of the paucity of inventory data on plants in landscapes both before and after urbanization, few studies have directly investigated this effect of urbanization. METHODS: We used historical, contemporary, and regional plant species inventories for Indianapolis, Indiana USA to evaluate how urbanization filters the bioregional flora based on species diversity, functional traits, and phylogenetic community structure. KEY RESULTS: Approximately 60% of the current regional flora was represented in the Indianapolis flora, both historically and presently. Native species that survived over time were significantly different in growth form, life form, and dispersal and pollination modes than those that were extirpated. Phylogenetically, the historical flora represented a random sample of the regional flora, while the current urban flora represented a nonrandom sample. Both graminoid habit and abiotic pollination are significantly more phylogenetically conserved than expected. CONCLUSIONS: Our results likely reflect the shift from agricultural cover to built environment, coupled with the influence of human preference, in shaping the current urban flora of Indianapolis. Based on our analyses, the urban environment of Indianapolis does filter the bioregional species pool. To the extent that these filters are shared by other cities and operate similarly, we may see increasingly homogenized urban floras across regions, with concurrent loss of evolutionary information
A comparison of the moss floras of Chile and New Zealand
Chile and New Zealand share a common stock of 181 species of mosses in 94 genera and 34 families. This number counts for 23.3% of the Chilean and 34.6% of the New Zealand moss flora. If only species with austral distribution are taken into account, the number is reduced to 113 species in common, which is 14.5% of the Chilean and 21.6% of the New Zealand moss flora. This correlation is interpreted in terms of long distance dispersal resp. the common phytogeographical background of both countries as parts of the palaoaustral floristic region and compared with disjunct moss floras of other continents as well as the presently available molecular data
Bryophyte floras of tropical Pacific islands
A review of the status of bryological research in each of the nations, states or governmental units of southern Melanesia, Micronesia and tropical Polynesia shows the imperfect state of knowledge about the Pacific tropical islands. Best known overall are Hawaii and Micronesia with Wallis and Futuna, the Marquesas and the high mountains of Fiji seeming to be the least known potentially species rich areas. Involvement of residents from Pacific islands in botanical study and preservation of ecosystems should be encouraged by tropical bryologists
Knowing what we count : a comment on Guo
Guo (2011) points to problems arising from different approaches to estimating the proportions of floras that are native or alien, specifically those across and within various regions. This results in inconsistency of numbers reported from internal administrative units by underestimating the numbers of species that are alien to the region and overestimating native species richness. Resulting species numbers and proportions for smaller units within large countries, or whole continents, can be seriously biased if only species alien to the larger unit as a whole are considered alien, while all other species are considered native
Plant strategies, dispersal and origins of flora at the northern Coral Sea Islands Territory, Australia
A checklist of vascular plants of Coringa-Herald National Nature Reserve (CHNNR) (17º 11’S, 149º 00’ E to 16º 23’S, 150º 30’E and Willis Island (16º 24’S, 149º 58’E) at the northern Coral Sea Islands Territory of Australia compiled during 2006/07 surveys, recorded 30 species including 18 species indigenous to the Coral Sea Islands (60%), 10 exotic species (33%) and two that were planted (7%). Plant life-forms included: 5 species of trees and tall shrubs (17%), 2 species of low shrubs (6.5%), 21 herbs (70%), and 2 vine/creepers (6.5%). Plant dispersal for the 30 species is predominantly by human activities (40%), ocean currents (33%) and seabirds (27%). The garden species and dispersal modes at Willis Island indicate that non-residential casual human visitation at CHNNR has at present had little effect on establishment of exotic weeds. Resilience of leverage flora, floristic diversity and species origins of CHNNR are discussed in relation to its connectivity with the Melanesian region due to the South Equatorial Current operating in the region. Colubrina asiatica was recorded as a new record for oceanic islands in Australian territories. Previously recorded Ximenia americana and Digitaria ctenantha are considered locally extinct. Pattern analyses indicate that cays of similar size and vegetation structure are the most similar in floristic composition. Willis Island flora is relatively dissimilar to the CHNNR cays, due to the influence of anthropogenic activities associated with a staffed weather station
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