Factors influencing the maintenance of an inverted Eucalyptus coccifera tree-line on the Mt Wellington Plateau,Tasmania

The Tasmanian snow gum, Eucalyptus coccifera Hook.f., forms low-open woodlands on the dolerite plateau of Mt Wellington, Tasmania. The species occurs at the inverted and upper slope tree-lines, and its spatial distribution appears to be strongly influenced by soil drainage characteristics. Both experimental work and field observations indicate that water-logging is the principal agent determining the inverted tree-line limits of E. coccifera on Mt Wellington. However, deficiencies of moisture also play a role in limiting the distribution of snow gums. There was no evidence to indicate that frost influences the lower tree-line limits of the species, despite the genetic variation shown in the frost resistance of trees from various provenances. Strong ice-bearing winds influenced the morphology of E. coccifera individuals, but was not a factor in limiting the distribution of the species.     

Plant communities of the Stirling Range,Western Australia

The Stirling Range is a mountain system of Proterozoic origin in the southern part of Western Australia, reaching an altitude of 1000 m; it consists of acid rocks and has a mediterranean climate with a rainfall of 500 - 550 mm/yr. It is the only extensive mountain system of this portion of the continent and presents a rich endemic flora. The vegetation of the area was investigated from 1984 to 1992; 68 phytosoci-ological releves, ecological observations and extensive floris-tic collections were made. On the basis of multivariate analysis eight communities have been distinguished: Eucalyptus woodland, mallee, evergreen shrubland (plain, mountain and slope), and herbaceous communities of wet sands, springs and rocks. The Stirling Range is the only area in the south of Western Australia where vegetation belts can be recognised.     

Cambrian agnostid communities in Tasmania

Jago, J. B.: Cambrian agnostid communities in Tasmania.
Two or possibly three different agnostid trilobite assemblages can be distinguished in the late Middle and early Upper Cambrian sequences of northern and western Tasmania. This is significant because in recent years agnostid trilobites have been widely used in local and international correlations of Middle and Upper Cambrian rocks. The three assemblages recognized are (1) an agnostid assemblage in which polymerid trilobites are abscnt, rare or present as thanatocoenotic fossils, (2) a ptychagnostid-non-nepeid assemblage, and (3) a nepeid-clavagnostid-peronopsid assemblage in which non-agnostid trilobites are abundant but ptychag-nostids are absent. It is proposed that assemblage (1) represents an open sea fauna, with assemblages (2) and (3) occurring in progressively shallower water.     

Tasmania revisited: rotifer communities and habitat heterogeneity

The results of four field surveys for Rotifera in Tasmania are summarized. Most new species and records in a 1987 survey were from acid waters (pH < 4.0) of dune lakes on the west coast (42° S). Marked intra- and interhabitat differences in rotifer communities of lakes and ponds were demonstrated by cluster analysis and related to habitat heterogeneity.     

Plant communities and habitat differentiation in the Mediterranean coniferous woodlands of Mt. Parnon (Greece)

Coniferous forests are a significant feature in the natural vegetation of the Mediterranean mountains, but most stands are rather degraded and the present distribution is just a fraction of its potential natural area. The Parnonas range (Peloponnese, Greece) ranks among the most extensive areas with a well-preserved mountain coniferous forest in the Mediterranean. The present paper aims at describing the conifer-dominated vegetation of this mountain and the ecological roles of the prevailing speciesAbies cephalonica, Pinus nigra, andJuniperus drupacea. For comparison, a survey is provided of theAbies cephalonica forests in the total distribution area, using all published relevés. Species composition and abundance, together with structural and abiotic parameters were recorded in 118 relevés distributed throughout Mt. Parnon. The phytosociological classification reveals 8 interpretable vegetation types well separated by groups of diagnostic species and presented in a synoptic table. The ecology and distribution of the units are outlined, and they are assigned to 4 associations within theAbietion cephalonicae (Helictotricho convoluti-Abietetum cephalonicae, Junipero drupaceae-Abietetum cephalonicae, Lilio chalcedonicae-Abietetum cephalonicae, Pyrolo chloranthae — Pinetum nigrae). The syntaxonomy and nomenclature of these associations, two of which are described as new, are discussed. The most important gradients in the data matrix found by detrended correspondence analysis (DCA) are related to altitude/climate and rockiness/soil. The communities are well segregated in the ordination space, and the fairly distinct clusters of the three conifer species are discussed. These conifers may be arranged along a gradient of decreasing drought tolerance fromJuniperus throughAbies toPinus. The latter is predominant and most vital essentially on schistose soils, or else reflects previous disturbance by, e.g., wildfires.Juniperus drupacea is a subordinate low tree or shrub in Tripolitza limestoneAbies forest. The vitality ofAbies cephalonica as expressed by tree height and structure is best in theLilio-Abietetum, between 1300 and 1600 m. The community variation within the total area of theAbietion cephalonicae reflects a principal differentiation in xerophytic and mesophytic stands. This pattern is encountered in various mountains and suggests that water supply is the crucial factor governing the floristic variation in the mountain coniferous forests.     

Local environmental correlates of variability in the organic soils of moorland and alpine vegetation,Mt Sprent,Tasmania

Abstract Data on soils, vegetation and environment were collected between 510 and 1050m a. s. l. on Mt Sprent, southwestern Tasmania, traversing the Gymnoschoenus sphaerocephalus sedgeland-alpine vegetation boundary. One or more of the following horizons were found in almost all soil pits (downwards from the surface to the bed rock) fibric peat, hemic peat, sapric peat, organic sand, sand and clay. Mean total soil depth, mean organic soil depth, mean humification of the soil surface horizon, pH and mean organic content of the surface horizon all decline with altitude, while the redness of the soil and the mean depth of the mineral and gravel layers increase. At four intensively studied sites at 620, 850, 930 and 1040 m the relationships between phytosociological, topographic and water-table variables, and soil characteristics were determined. The pH of the topsoil was significantly positively related to water-table depth at three sites, but there were no other relationships between local environmental variation and soil characteristics that were consistent between most of the four sites, despite a large number of locally significant relationships. The alpine and sedgeland soils differ most markedly in colour, number of horizons and degree of humification of the surface horizon. The vegetation at each site was separated into communities along a drainage gradient. The mesoscale differences in soils seem most likely to be attributable to a vegetation productivity gradient.     

Species Diversity,Distribution, and Microhabitats of Anurans on Mt. Kalo-Kalo of the Mt. Kalatungan Range Natural Park,Bukidnon, Philippines

Anurans are considered good indicators of habitat quality due to their bi-phasic life mode,limited dispersal abilities,and sensitivity to environmental changes brought about by habitat fragmentation,pollution,climate change,and emerging infectious diseases.This study aimed to determine species diversity and local distribution of anurans in lower(1000–1400 masl)and upper(1400–1600 masl)montane forests on Mt.Kalo-Kalo of the Mt.Kalatungan Range Natural Park,Central Mindanao,Southern Philippines by employing standard sampling techniques for amphibians.We recorded a total of 251 individual anurans,representing 12 species during a brief recent study period.Mt.Kalo-Kalo’s upper montane forest has a higher diversity index(H’=1.276)than the lower montane forest(H’=0.851).Despite the very low diversity indices,the level of endemism of anurans was 100%where ten of the recorded species are Mindanao Faunal Region endemics and an additional two species are Philippine endemics.Ansonia muelleri exhibited the highest local abundance and individuals of this species which constituted 73%of individual anurans observed.Most of the species encountered prefer terrestrial and aquatic microhabitats,specifically on the rocks and bank substrates along the rivers and streams.Three species of anurans(Philautus acutirostris,P.poecilius,and Rhacophorus bimaculatus)were strictly found in arboreal microhabitats.Limnonectes magnus and A.muelleri have overlapping microhabitats.Results indicate that for such a short survey and modest sampling effort,the lower and upper montane forests of Mt.Kalo-Kalo support high endemism of anuran species suggesting that conservation efforts continue to be a priority in this unique protected area.     

Plant communities of the Accra Plains,Ghana

A new classification, using the Zürich-Montpellier procedures, is presented for the grassland, thicket and forest vegetation of the Accra Plains, Ghana. Newly described syntaxa comprise 1 class (Vetiverietea), 4 orders, 9 alliances, 16 associations and 16 subassociations. Altogether 350 species of vascular plants were recorded in 140 relevés. Correlations are made between syntaxa and climatic, edaphic and anthropogenic factors. The floristic distinctness of the area is assessed: 4 endemic species and about 40 widely disjunct species occur. Although the majority of species are of Guinean affinity, the plant communities of the Accra Plains are unique in the context of African tropical vegetation.     

Montane vegetation of the Mt. Field massif,Tasmania: a test of some hypotheses about properties of community patterns

direct gradient analysis was applied to the montane vegetation of the Mt. Field massif, Tasmania. Ecological response surface were constructed, describing the relationship between the mean % cover of each of 100 vascular plant species and two major environmental complex-gradients represented by soil drainage and altitude. The hypotheses tested were that: (1) the ecological responses of species are generally of Gaussian form; (2) the modes of minor species have a uniform random distribution along gradients; (3) the modes of major species are evenly distributed; (4) the frequency distribution over species of modal abundance is either lograndom or lognormal; and (5) alpha diversity has a unimodal trend along environmental gradients. The hypotheses were tested both for the full site of vascular species and for each of five species groups defined by structural form. Hypothesis (1) was rejected: only 45% of species had response surface which appeared unimodal and symmetric. Hypotheses (2) and (4) were rejected for the full set of species, but each was supported for all but one of the structural groups. The modes of herb species were clumped, rather than random and the frequency distribution of modal percentage cover for shrubs was inconsistent with both lograndom and lognormal hypotheses. Contrary to hypothesis (3), the modes of major species were randomly distributed. Although total alpha diversity had a complex trend surface, the patterns for the alpha diversities of each structural group were unimodal, in accordance with hypothesis (5). The results suggest that an adequate model of community variation along environmental gradients must take into account differences in response patterns between species groups.     

Host Range of,and Plant Reaction to,Subanguina picridis

The host range of the knapweed nematode, Subanguina picridis (Kirjanova) Brzeski, under controlled environmental conditions was extended to include, in addition to Russian knapweed, Acroptilon repens (L.) DC., plant species within the Centaureinae, and Carduinae subtribes of the Cynareae tribe of the Asteraceae family. Examination of host response to nematode infection revealed that Russian knapweed was the only highly susceptible host plant. Diffuse knapweed (Centaurea diffusa Lam.) was moderately susceptible, and other plants which formed galls were resistant to S. picridis.     

Decision-making processes in ecological risk assessment using copper pollution of Macquarie Harbour from Mt. Lyell, Tasmania, as a case study

Ecological risk assessment is increasingly being used to make decisions on the acceptability of industrial processes, as well as on the appropriate approach to take with remediation of contaminated sites. In this approach, the risks and costs must first be determined before decisions can be made. In principle, the procedure for undertaking an ecological risk assessment for a site with existing contamination is fairly straight forward. Probability distributions are obtained for the concentration of the contaminant of concern and for the biological and/or structural impacts likely to occur in the affected habitat. The degree of overlap between these distributions determines the risk from the contaminant to the habitat. With water-borne contamination, the level of assessment can vary from a simple comparison with water quality criteria, through site specific literature surveys, to laboratory and field studies depending on the importance of the environment, the concentration and perceived nature of the contaminant,the resources available, and the likely benefit from the process to be developed. However, a number of uncertainties make this process more difficult. These include the lack of a standard methodology, availability of appropriate data and agreed definitions of acceptable risk. Thus several arbitrary or considered decisions need to be made before and during such an assessment. This paper discusses the application of an ecological risk assessment of copper pollution in Macquarie Harbour, Tasmania, using data from long-term monitoring of waters and literature searches on lethal and sub-lethal effects of copper in marine and estuarine environments. This study is part of a much larger program established to determine best methods for the remediation of the Mt. Lyell copper mine site as well as the freshwater and marine habitats downstream. The results of the assessment indicated that there was at present a probability greater than0.9 of the occurrence of anodic stripping voltametry-labile copper water concentrations harmful to 5% of all species. For total dissolved copper the probability was higher than 0.98. The upper value of total dissolved copper in Macquarie Harbour that encompassed 90% of the probable concentrations would need to be reduced by a factor of approximately 30,without the inclusion of any additional application factors, to achieve (sub-lethal) protection for 95%of species. This revised version was published online in August 2006 with corrections to the Cover Date.     

Snow-land communities of Reykjanes Peninsula,SW. Iceland (Plant communities of Reykjanes Peninsula,part 4)

Snow-land communities in Reykjanes Peninsula are represented by the associationsHylocomio-Salicetum herbaceae, Rhodiolo-Bartsietum alpinae andRhytidiadelpho-Poetum alpinae, belonging to a new alliance,Antitrichio-Rhodiolion, and byAnthelietum Juratzkanae, Sibbaldio-Salicetum herbaceae andSibbaldietum procumbentis, belonging to the allianceSalicion herbaceae s. l. Their syntaxonomy and ecology are discussed.     

Mire communities of Reykjanes peninsula,SW. Iceland (Plant communities of reykjanes peninsula,part I.)

In Reykjanes peninsula, mainly in the valley of Krísuvík, in all 6 mire associations were found, belonging to the alliancesEriophorion Scheuchzeri andCaricion canescentis-fuscae. Floristic, ecological and physiognomical differeces between the two alliances are discussed. Most of the associations seem to be restricted in their distribution to Iceland.     

The butterfly fauna (Lepidoptera,Rhopalocera) of the Kungey Ala-Too Mt. Range (Northern Tien Shan)

The butterfly fauna of the Kungey Ala-Too Mt. Range comprises 181 species, among them 58 are identified for the first time. Zoogeographic analysis of this fauna showed that a complex of butterflies with wide ranges predominated, whereas representatives of the Central Asian ranges had a smaller portion by 20%. Nowadays, the Kungey Ala-Too is a bridge between the faunas of the Western Tien Shan (Alai) and Southern Siberia.     

Plant communities along the Medina-Badr road across the Hejaz mountains,Saudi Arabia

The present study gives an assessment of the environmental factors and their effect on the pattern and distribution of the plant communities in the area along the road from Medina to Badr, Saudi Arabia. The road crosses the Hejaz mountains and the study area presents three main ecogeomorphological systems which are differentiated into various habitats. Rainfall and plant cover show wide variation, both in quantity and distribution in the different sectors of the study area. Also, the wide variations in topography, rock types and soil characteristics, have a marked influence on the water resources and consequently on the vegetation.Twenty-three communities, recognized by species dominance and habitat features, have been distinguished. These include ten communities dominated by trees and shrubs; five of them are dominated by one of the Acacia spp. growing in the area. Seven communities are dominated by suffrutescent species and six are dominated by ephemeral species. The latter communities appear only during the wet season and disappear at the beginning of summer. The floristic conoposition and the habitat features are described and the ecological relationships between the communities are briefly discussed.Nomenclature follows Taeckholm (1974) and Migahid (1979).The authors are grateful to Mr S. Ads for his assistance in the field work.Dedicated to Haj Hassan El-Batanouny, deceased and buried at Al-Hamrah, Hejaz in 1911.     

Plant communities in the terrestrial-aquatic transition zone in the paramo of Chingaza, Colombia

Plant communities in the terrestrial-aquatic transition zone in the paramo of Chingaza, Colombia. High Andean paramo ecosystems are an important water resource for many towns, and major cities in this region. The aquatic and wetland vegetation of different paramo lakes, pond, swamps and bogs was studied according to the classical phytosociological approach, which is based on homogenous stands, but excludes any border phenomena or transitional zone. The present research aimed at determining the aquatic and wetland vegetation along different moisture gradients. A total of 89 species in 30 transects were reported, of which Crassula venezuelensis, Carex honplandii, Callitriche nubigena, Eleocharis macrostachya, Ranunculus flagelliformis, R. nubigenus, Eleocharis stenocarpa, Galium ascendens y Alopecurus aequalis were present in more than one third of the transects. Numerical classification and indicator species analysis resulted in the definition of the next 18 communities: 1) Calamagrostis effusa, 2) Sphagnum cuspidatum, 3) Cyperus rufus, 4) Eleocharis stenocarpa, 5) Carex acutata, 6) Poa annua,7) Valeriana sp., 8) Ranunculus flagelliformis, 9) Carex bonplandii, 10) Festuca andicola. 11) Muhlenbergia fustigiata, 12) Elatine paramoana, 13) Iso?tes palmeri, 14) Crassula venezuelensis, 15) Lilaeopsis macloviana, 16) Callitriche nubigena, 17) Potamogeton paramoanus and 18) Potamogeton illinoensis. The ordination of communities reveals the presence of three different aquatic-terrestrial gradients which are related to the life form structure of species that characterized the various communities. We concluded that patchiness and heterogeneity of the vegetation is mainly the result of alterations caused by human activities (burning, cattle raise and material extraction for road and dam construction).