共查询到20条相似文献,搜索用时 15 毫秒
1.
Marilen M. Parungao Sally C. Fryar Kevin D. Hyde 《Biodiversity and Conservation》2002,11(7):1185-1194
Ten leaves from each of 13 different tree types from two differentrainforest sites in North Queensland, Australia were examined in order toestablish the fungal diversity developing on these leaves. A total of 57microfungi were identified, most of which were mitosporic fungi. Speciesdiversity in terms of richness and evenness were compared and the Mt Lewis sitewas found to be richer as compared to the Butchers Creek site. Statisticalmeasurements of diversity indices, however, showed that the two forest siteswere of similar diversity. Thirty-six of the fungi identified occurred only onone leaf type, indicating possible host specificities or recurrences. The samplesize, however, is deemed to be insufficient, as a larger sample size may haveresulted in less of the fungi appearing to be host specific. It is recommendedthat future studies should include more leaf samples and less tree types. It isparticularly important that the same leaf species are collected within the samesite and at different sites in order to establish the effects of host on fungalcomposition. 相似文献
2.
Charcoal fragments, some identified as Eucalyptus, with radiocarbon dates spanning the period 27 000–12 000 years bp , were found in a soil profile under moist tropical rainforest in north-eastern Australia. The charcoal indicates that sclerophyll forest occupied a central part of the Windsor Tableland rainforest massif during the late Pleistocene. The widespread presence of identifiable and dateable charcoal under rainforest in north Queensland provides an opportunity to examine the patterns and ecological implications of fluctuations in rainforest distribution in recent history. 相似文献
3.
Rodent zoonoses in North Queensland: the occurrence and distribution of zoonotic infections in North Queensland rodents 总被引:3,自引:0,他引:3
J S Glazebrook R S Campbell G W Hutchinson N D Stallman 《The Australian journal of experimental biology and medical science》1978,56(2):147-156
A study of potentially zoonotic infections was carried out on 351 rodents trapped in north-eastern Queensland. Their ecosystems included towns, agricultural and livestock areas, wookland and rainforest. Nine serotypes of salmonellae were obtained from asymptomatic carries in predominantly settled locations. Two strains of Ps. pseudomallei occurred in rainforest near Innisfail and one on a cattle property adjacent to Townsville. Ps. aeruginosa caused bronchopneumonia in one animal from Townsville harbour. Ifection by leptospirae of six serogroups and seven serovars were identified by serological or cultural examinations. Enzootic foci occurred on the Mount Spec rainforest where celledoni and australis were being excreted by rats adjacent to the Paluma dam system. In addition to the scrub typhus locations at Rocky Creek, Atherton Tableland and Bullocky Creek, near Ingham, which were confirmed, a new focus of infection by R. tsutsugamushi was identified at El Arish near Tully. Water rat (H. chrysogaster) at Townsville harbour constituted a reservoir of toxoplasmosis. In addition to the known human pathogenic helminths H. nana and H. diminuta, localized foci of hookworms (Ancylostoma spp.) were found. Histological evidence of cytomegalic disease of the salivary glands or kidneys was a common finding. 相似文献
4.
We studied the feeding ecology of the bongo (Tragelaphus eurycerus) in the Dzanga National Park in the rainforest of the Central African Republic to understand better the trade-off between
food selectivity, ranging behaviour and social organization of a large, forest-dwelling, social antelope. Food plants and
vegetation types were registered along a 311-km route travelled by bongos. Food availability was determined by identifying
and counting the plants in 19 randomly chosen forest plots. Bongos showed pronounced selectivity for 26 out of 100 woody forest
species. They predominantly consumed younger leaves, which suggests that high protein and low fibre content influence plant
choice. In addition to leaves, bongos also ate fruits of two and flowers of one species. Furthermore, the diet was supplemented
by grasses and herbs consumed on large natural licks. Such licks were regularly visited by the bongos. According to Jarman's
ecological classification of antelopes, selective browsers are relatively small and live alone or in pairs to avoid competition
over food. The bongo's large size and gregariousness should not allow it to survive in the rainforest as a pure selective
browser. Our data suggest that the bongo relies on the opportunity to graze in bulk which it finds on the natural licks. We
hypothesize that such licks either limit the distribution of bongos in other rainforest areas or allow larger group sizes
than in areas without licks.
Received: 8 June 1998 / Accepted: 30 November 1998 相似文献
5.
The evolutionary history of Fagus in western Eurasia: Evidence from genes, morphology and the fossil record 总被引:2,自引:0,他引:2
T. Denk G. Grimm K. Stögerer M. Langer V. Hemleben 《Plant Systematics and Evolution》2002,232(3-4):213-236
Fagus (beech) is among the most abundant and economically important genera of broad-leaved trees in northern hemisphere temperate
forests. The number of modern taxa present in Europe and Asia Minor has long been a matter of debate and up to five species
have been recognised. To resolve taxonomic and phylogenetic relationships we conducted morphological and molecular genetic
analyses in western Eurasiatic taxa and evaluated palaeontological evidence. To place our findings from western Eurasiatic
populations in a broader context additional East Asiatic and North American species of the same subgenus Fagus as well as two species of the subgenus Engleriana were included in our study.
The morphological features exhibited in western Eurasiatic populations of Fagus show a west-east gradient that is characterised by strongly overlapping variability between geographical races. Fagus populations from Asia Minor exhibit an even higher variability that is also reflected in their genetic variability of nuclear
rDNA internal transcribed spacer (ITS) sequences. The intraspecific genetic variability recorded here is in conflict with
previous ITS studies in Fagus. The high amount of ITS polymorphism within Fagus from western Eurasia along with the clinal variation observed for morphological characters suggest the presence of only a
single species, Fagus sylvatica L., in Europe and Asia Minor. Previously recognised taxa such as F. orientalis Lipsky and Fagus moesiaca (Maly) Czeczott should therefore be treated as synonyms of Fagus sylvatica. Although species belonging to the subgenus Engleriana were genetically distinct from species of the subgenus Fagus, relationships within the subgenus Fagus could not be clearly resolved. A reason for this could be the low rate of diversification in Fagus during the early phase of range expansion of the genus in the Oligocene period as indicated by the uniformity of leaf and
cupule/nut fossils. This may account for the low overall ITS divergence and the high degree of polymorphism encountered in
the subgenus Fagus and points to a late differentiation of western Eurasiatic and eastern Asiatic species. Area disruptions during the Pleistocene
and the post-glacial recolonisation of western Europe appear to have caused the west-east gradient that is apparent in modern
Fagus of western Eurasia but absent in Late Tertiary ancestors of Fagus sylvatica.
Received June 22, 2001 Accepted February 25, 2002 相似文献
6.
Corinna Erckenbrecht Maureen Fuary Shelley Greer Rosita Henry Russell McGregor Michael Wood 《The Australian journal of anthropology》2010,21(3):350-366
This paper outlines some of the ways early artefact collecting contributed to the definition of the Australian region now known and marketed as the ‘World Heritage Wet Tropics’. While others have collected in this region, we focus on the collecting activities of Hermann Klaatsch and the work of Norman Tindale to explore some factors that contributed to their claims that certain artefacts represent a region and its history. We argue that these understandings of region and the past, along with the now widely dispersed artefacts, maintain a lively, albeit transformed, presence in current debates about Aboriginal regional culture, linking assertions of rights to lost and stolen cultural property with notions of large‐scale environmental management within the ‘Wet Tropics’. 相似文献
7.
Dena M. Smith Jonathan D. Marcot 《Proceedings. Biological sciences / The Royal Society》2015,282(1805)
Coleoptera (beetles) is the most species-rich metazoan order, with approximately 380 000 species. To understand how they came to be such a diverse group, we compile a database of global fossil beetle occurrences to study their macroevolutionary history. Our database includes 5553 beetle occurrences from 221 fossil localities. Amber and lacustrine deposits preserve most of the beetle diversity and abundance. All four extant suborders are found in the fossil record, with 69% of all beetle families and 63% of extant beetle families preserved. Considerable focus has been placed on beetle diversification overall, however, for much of their evolutionary history it is the clade Polyphaga that is most responsible for their taxonomic richness. Polyphaga had an increase in diversification rate in the Early Cretaceous, but instead of being due to the radiation of the angiosperms, this was probably due to the first occurrences of beetle-bearing amber deposits in the record. Perhaps, most significant is that polyphagan beetles had a family-level extinction rate of zero for most of their evolutionary history, including across the Cretaceous–Palaeogene boundary. Therefore, focusing on the factors that have inhibited beetle extinction, as opposed to solely studying mechanisms that may promote speciation, should be examined as important determinants of their great diversity today. 相似文献
8.
9.
Jim I. Mead 《Geobios》2013
An abundant fossil record of the snake clade Scolecophidia exists in Europe; however, the minute snake is noticeably absent in reports about the North American Paleogene and Neogene. Presented here are four localities from Florida, USA, that contain scolecophidian remains older than the Pleistocene: Thomas Farm (late Early Miocene, Hemingfordian Land Mammal Age, LMA), Live Oak (Oligocene-Miocene transition, latest Arikareean LMA), White Springs 3B (late Arikareean LMA), and Brooksville 2 (Late Oligocene, middle Arikareean LMA). These remains extend their known existence by about 26 m.y. and are now the oldest reported scolecophidian remains in North America. Molecular evidence on extant scolecophidians concludes that these tiny snakes have a Gondwanan origin. Interestingly, the oldest record of a scolecophidian is from Europe (Belgium) and dates back to the middle Paleocene (MP 1–5). The earliest African record of the snake clade comes from the Paleocene-Eocene boundary in Morocco. The clade is apparently absent from Europe and Middle East deposits dating from the latest Eocene through to the latest Oligocene (MP 19–30) and to the Early Miocene (MN 4). A portion of this time is known as the booid ‘Dark Period’ which represents an apparent response to global aridization and cooling. Scolecophidians appear to re-emerge into the southern Eurasian record in the Early Miocene (MN 4) and become widely dispersed throughout Europe and Middle East. The fossil record of these minute snakes is largely absent in southern Asia and South America. It is possible that the current lack of a decent fossil scolecophidian record outside of Europe and Middle East is due mainly to a bias in the methodology to recover fossils; wet sieving sediments through < 1.0 mm mesh is needed to recover the minuscule vertebrae. 相似文献
10.
The tiger salamander,Ambystoma tigrinum, is a geographically widespread, morphologically variable, polytipic species. It is among the most variable species of salamanders
in morphology and life history with two larval morphs (typical and cannibal) and three adult morphs (metamorphosed, typical
branchiate, cannibal branchiate) that vary in frequency between subspecies and between populations within subspecies. We report
morphometric evidence suggesting that branchiate cannibals arose through intraspecific change in the onset or timing of development
resulting in the wider head and hypertrophied tooth-bearing skull bones characteristic of this phenotype. We also quantified
bilateral symmetry of gill raker counts and abnormalities, then evaluated fluctuating asymmetry as a measure of the developmental
stability of each morph. There was a significant interaction between fluctuating asymmetry of developmental abnormalities
in cannibals and typicals and the locality where they were collected, suggesting that relative stability of each phenotype
could vary among populations. While altered timing of developmental events appears to have a role in the evolution and maintenance
of morphs, novel phenotypes persist only under favorable ecological conditions. Predictability of the aquatic habitat, genetic
variation, kinship, body size, intraspecific competition and predation all affect expression and survival of the morphs inA. tigrinum. This taxon provides an excellent model for understanding the diversity and complexity of developmental and ecological variables
controlling the evolution and maintenance of novel phenotypes. 相似文献
11.
12.
Diversity and ecology of saxicolous vegetation mats on inselbergs in the Brazilian Atlantic rainforest 总被引:1,自引:0,他引:1
STEFAN POREMBSKI GUSTAVO MARTINELLI RALF OHLEMÜLLER & WILHELM BARTHLOTT 《Diversity & distributions》1998,4(3):107-119
Inselbergs occur as mostly dome-shaped rock outcrops in all climatic and vegetational zones of the tropics. Consisting of Precambrian granites and gneisses, they form ancient and stable landscape elements. Due to harsh edaphic and microclimatic conditions, the vegetation of inselbergs differs markedly from those of the surroundings. Monocotyledonous mats form one of the most characteristic communities of this ecosystem. The floristic composition of this community was studied on six inselbergs located in the Brazilian Atlantic rainforest. Dominating are Bromeliaceae ( Alcantarea , Encholirium ), Velloziaceae ( Vellozia ), Cactaceae ( Coleocephalocereus ) and the Cyperaceae Trilepis . The alpha diversity of the mats was relatively uniform among the six outcrops. However, beta diversity varied considerably between the different sites. Beta diversity was highest at the most speciose locality indicating a high degree of stochasticity in colonization. In contrast to the low diversity mats on West African inselbergs, the Brazilian rock outcrops bear a floristically more diverse mat community rich in endemics. Thus the edaphically controlled inselberg vegetation reflects the outstanding diversity of the Mata Atlaântica. Possibly the high species richness of mats on East Brazilian inselbergs is a consequence of a large species-pool. The processes that regulate regional and local diversity in the Mata Atlaântica are not fully clear. It is assumed that historical (i.e. long-term stability) and biotic (i.e. evolutionary interchange of taxa between canopies and rock outcrops followed by differentiation of local populations) conditions have promoted high rates of speciation and their coexistence in isolated habitats. A danger to the unique vegetation of East Brazilian inselbergs is the establishment of invasive weeds. 相似文献
13.
Summary Four shrub species of the Australian Proteaceae (Hakea sericea, H. gibbosa, H. suaveolens and H. salicifolia) were introduced to South African fynbos shrublands between 1840 and 1860. H. sericea is highly invasive, H. gibbosa and H. suaveolens are moderately invasive and H. salicifolia is not invasive. The allocation of reproductive energy, germinability, the ability to survive fires and to germinate in burnt and unburnt areas, and the nutrient content of seeds were assessed for the four species. The information was used to investigate whether the success of H. sericea relative to the other three species could be explained by the superior expression of any trait. The most important trait which separates H. sericea from the other species is its ability to produce a large seed bank in its adopted environment in the absence of seed predators. Seed production in H. sericea shrubs with an above-ground dry mass of 8 kg is four times greater than H. gibbosa and more than 16 times that of H. suaveolens. Although H. salicifolia also produces a large seed bank, its seeds are unable to survive fires due to inadequate insulation by the small follicles. The results are compared to dispersal and seed bank data for indigenous South African Proteaceae, which have low dispersal and suffer high pre-dispersal seed predation. We suggest that potential invasives in the fynbos can be identified as species that have: (i) a potentially high seed production that is limited by specialized predators; (ii) an ability to disperse over long distances; and (iii) are pre-adapted to frequent fires and low soil nutrients. The data also support the current strategy of combatting H. sericea using specialized insect seed predators. 相似文献
14.
Misodendraceae is a small family of mistletoes in the order Santalales. Its distribution is restricted to the southern South American temperate forests. The family comprises the sole genus Misodendrum with eight species of hemiparasitic shrubs, mainly parasitising the southern beech Nothofagus. This contribution presents palynological evidence from seven species, using light microscopy and scanning electron microscopy. Pollen grains are consistently small, periporate and echinate, although differences in the length of echini and number and size of pores were noted. Pollen features can be used to distinguish groups of species and, in some cases, individual species. Cluster analysis of pollen characters differentiates two main groups: one includes M. brachystachyum, M. oblongifolium and M. quadriflorum; and the other includes M. gayanum, M. linearifolium, M. punctulatum and M. angulatum. Palynological results are compared with previous systematic studies of the family. The South American fossil pollen record is summarised and characters of the fossil pollen are analysed using UPGMA to test the relationships between extant and fossil species. Miocene pollen resulted similar to species of subgenus Angelopogon while Eocene pollen is disimilar to extant species of Misodendraceae. 相似文献
15.
The present paper reports on palynology and pollination ecology of eight taxa of Amorphophallus from North Western Ghats (NWGS) and Konkan region of India. Out of ten known pollen exine ornamentations of the genus, six are represented – psilate, striate, fossulate, verrucate, scabrate and the new type ‘pseudofossulate’ of Amorphophallus commutatus var. wayanadensis. These diverse pollen exine ornamentations can be utilized as an important taxonomic tool to distinguish taxa and also to resolve taxonomic problems (A. commutatus complex). The pollen of all eight taxa had retained their sculptured surface (exine ornamenatation type) after acetolysis. This clearly demonstrates that these taxa do not show susceptibility to the conventional acetolysis technique as reported earlier. The present study also highlights the importance of pollen surface morphology concerning phytogeography of the genus. 相似文献
16.
Fossil onagraceous pollen grains from two Upper Miocene localities in E. Austria were investigated by LM and EM. Exine structure and sculpture as well as viscin threads suggest affinities with the extant genusCircea. 相似文献
17.
Land use and the ecology of benthic macroinvertebrate assemblages of high-altitude rainforest streams in Uganda 总被引:3,自引:0,他引:3
1. In sub‐Saharan Africa, tropical forests are increasingly threatened by accelerating rates of forest conversion and degradation. In East Africa, the larger tracts of intact rainforest lie largely in protected areas surrounded by converted landscape. Thus, there is critical need to understand the functional links between large‐scale land use and changes in river conditions, and the implications of park boundaries on catchment integrity. 2. The objective of this study was to use the mosaic of heavily converted land and pristine forest created by the protection of the high‐altitude rainforest in Bwindi Impenetrable National Park, Uganda to explore effects of deforestation on aquatic systems and the value of forest in buffering effects of adjacent land conversion. A set of 16 sites was selected over four drainages to include four categories of deforestation: agricultural land, deforested upstream (of the park boundary), forest edge (park boundary) and forest. We predicted that forest buffer (downstream or on the edge) would moderate effects of deforestation. To address this prediction, we quantified relationships between disturbance level and both physicochemical characters and traits of the macroinvertebrate assemblages during six sampling periods (February 2003 and June 2004). 3. Results of both principal components analysis and cluster analyses indicated differences in limnological variables among deforestation categories. PC1 described a gradient from deforested sites with poor water quality to pristine forested sites with relatively good water quality. Agricultural sites and deforested upstream sites generally had the highest turbidity, total dissolved solids (TDS), and conductivity values and low transparency values. Forest sites and boundary site groups generally exhibited low turbidity, TDS, and conductivity values and high water transparency values. Sites also clustered according to deforestation categories; forest and forested edge sites formed a cluster independent of both agricultural land and deforested‐upstream. 4. Water transparency, water temperature, and pH were the most important factors predicting benthic macroinvertebrate assemblages. Sensitive invertebrate families of Trichoptera, Ephemeroptera, Plecoptera, and Odonata dominated forested sites with high water transparency, low water temperature, and low pH while the tolerant families of Ephemeroptera, Diptera, Hemiptera, and Coleoptera were abundant in agriculturally impacted sites with low water transparency, high water temperature, and high pH. 5. This study provides support for the importance of riparian buffers in moderating effects of deforestation. Forest and forested edge sites were more similar in both limnological and macroinvertebrate assemblage structure than sites within or downstream from agricultural lands. If the protected area cannot encompass the catchment, the use of rivers as park boundaries may help to maintain the biological integrity of the rivers by buffering one side of the watercourse. 相似文献
18.
Functional morphology of the asterionic region in extant hominoids and fossil hominids 总被引:1,自引:0,他引:1
Asterionic sutural patterns in Plio-Pleistocene hominid crania have never been examined in detail. We present an analysis of this anatomical region in Australopithecus and Homo and relate different sutural patterns to functional changes in the masticatory apparatus. The great apes and A. afarensis share the common adult higher primate sutural pattern referred to as the "asterionic notch," which develops in response to the hypertrophy of posterior temporalis muscle fibers and the consequent formation of compound temporal/nuchal crests. This sutural configuration also appears to be present on the early Homo cranium KNM-ER 1805. In contrast, adult male A. boisei crania exhibit a unique pattern where the temporal squama overlaps the parietal which, in turn, overlaps the par mastoidea and the upper scale of the occipital bone. We relate this arrangement to the need to reinforce the rear of a thin-walled braincase against the net tensile forces exerted by the temporalis and nuchal muscles. The common juvenile hominoid edge-to-edge asterionic articulation is maintained in adult A. africanus, A. robustus, female A. boisei, and most Homo crania. We discuss the latter pattern in regard to anterior temporalis hypertrophy in A. africanus, A. robustus, and A. boisei and to craniofacial paedomorphosis in Homo. 相似文献
19.
Drapeau MS 《Journal of human evolution》2008,55(1):86-102
Extant hominoids share similar elbow joint morphology, which is believed to be an adaptation for elbow stability through a wide range of pronation-supination and flexion-extension postures. Mild variations in elbow joint morphology reported among extant hominoids are often qualitative, where orangutans are described as having keeled joints, and humans and gorillas as having flatter joints. Although these differences in keeling are often linked to variation in upper limb use or loading, they have not been specifically quantified. Many of the muscles important in arboreal locomotion in hominoids (i.e., wrist and finger flexors and extensors) take their origins from the humeral epicondyles. Contractions of these muscles generate transverse forces across the elbow, which are resisted mainly by the keel of the humeroulnar joint. Therefore, species with well-developed forearm musculature, like arboreal hominoids, should have more elbow joint keeling than nonarboreal species. This paper explores the three- and two-dimensional morphology of the trochlear notch of the elbow of extant hominoids and fossil hominins and hominoids for which the locomotor habitus is still debated. As expected, the elbow articulation of habitually arboreal extant apes is more keeled than that of humans. In addition, extant knuckle-walkers are characterized by joints that are distally expanded in order to provide greater articular surface area perpendicular to the large loads incurred during terrestrial locomotion with an extended forearm. Oreopithecus is characterized by a pronounced keel of the trochlear notch and resembles Pongo and Pan. OH 36 has a morphology that is unlike that of extant species or other fossil hominins. All other hominin fossils included in this study have trochlear notches intermediate in form between Homo and Gorilla or Pan, suggesting a muscularity that is less than in African apes but greater than in humans. 相似文献
20.
Marianne Plhak 《Journal of human evolution》1980,9(8):587-589
Los Angeles Man and Laguna Woman are two of the oldest, absolutely dated fossil hominids in America. With their 23,600 years B.P. and 17,150 ± 1470 years B.P., respectively, these two individuals are more than 10,000 years older than most of the absolute dated human remains discovered on this continent. They are described here in detail and compared with early representatives of our species from North America and Asia. Moreover, an attempt will be made to classify them typologically. 相似文献