8,927 research outputs found

    Native vegetation of the southern forests : south-east highlands, Australian alps, south-west Slopes, and SE Corner bioregions

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    The Southern Forests study area covers an area of about six million hectares of south-eastern New South Wales, south of Oberon and Kiama and east of Albury and Boorowa (latitude 33° 02’–37 ° 06’ S; longitude 146° 56’ – 147° 06’ E). The total area of existing vegetation mapped was three million hectares (3 120 400 hectares) or about 50% of the study area. Terrestrial, wetland and estuarine vegetation of the Southern Forests region were classified into 206 vegetation groups and mapped at a scale between 1: 25 000 and 1: 100 000. The classification was based on a cluster analysis of detailed field surveys of vascular plants, as well as field knowledge in the absence of field survey data. The primary classification was based on 3740 vegetation samples with full floristics cover abundance data. Additional classifications of full floristics presence-absence and tree canopy data were carried out to guide mapping in areas with few full floristic samples. The mapping of extant vegetation was carried out by tagging vegetation polygons with vegetation codes, guided by expert knowledge, using field survey data classified into vegetation groups, remote sensing, and other environmental spatial data. The mapping of pre-1750 vegetation involved tagging of soils mapping with vegetation codes at 1: 100 000 scale, guided by spatial modelling of vegetation groups using generalised additive statistical models (GAMS), and expert knowledge. Profiles of each of the vegetation groups on the CD-ROM* provide key indicator species, descriptions, statistics and lists of informative plant species. The 206 vegetation groups cover the full range of natural vegetation, including rainforests, moist eucalypt forests, dry shrub forests, grassy forests, mallee low forests, heathlands, shrublands, grasslands and wetlands. There are 138 groups of Eucalyptus forests or woodlands, 12 rainforest groups, and 46 non-forest groups. Of the 206 groups, 193 were classified and mapped in the study area. Thirteen vegetation groups were not mapped because of their small size and lack of samples, or because they fell outside the study area. Updated regional extant and pre-1750 vegetation maps of southern New South Wales have been produced in 2005, based on those originally prepared in 2000 for the southern Regional Forest Agreement (RFA). Further validation and remapping of extant vegetation over 10% of the study area has subsequently improved the quality of the vegetation map, and removed some of the errors in the original version. The revised map provides a reasonable representation of native vegetation at a scale between 1: 25 000 and 1: 100 000 across the study area. In 2005 native vegetation covers 50% of the study area. Environmental pressures on the remaining vegetation include clearing, habitat degradation from weeds and nutrification, severe droughts, changing fire regimes, and urbanisation. Grassy woodlands and forests, temperate grasslands, and coastal and riparian vegetation have been the most reduced in areal extent. Over 90% of the grassy woodlands and temperate grasslands have been lost. Conservation of the remaining vegetation in these formations is problematic because of the small, discontinuous, and degraded nature of the remaining patches of vegetation

    Tree dynamics and co-existence in the montane¿sub-alpine ecotone: the role of different light-induced strategies

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    Questions: Is light availability the main factor driving forest dynamics in Pyrenean sub-alpine forests? Do pines and firs differ in growth, mortality and morphological response to low light availability? Can differences in shade tolerance affect predictions of future biome changes in Pyrenean sub-alpine forests in the absence of thermal limitation? Location: Montane-sub-alpine ecotones of the Eastern Pyrenees (NE Spain). Methods: We evaluated morphological plasticity, survival and growth response of saplings of Scots pine, mountain pine and silver fir to light availability in a mixed forest ecotone. For each species, we selected 100 living and 50 dead saplings and measured size, crown morphology and light availability. A wood disk at root collar was then removed for every sapling, and models relating growth and mortality to light were obtained. Results: Fir had the lowest mortality rate (<0.1) for any given light condition. Pines had comparable responses to light availability, although in deep shade Scots pine risked higher mortality (0.35) than mountain pine (0.19). Pines and fir developed opposing strategies to light deprivation: fir employed a conservative strategy based on sacrificing height growth, whereas pines enhanced height growth to escape from shade, but at the expense of higher mortality risk. Scots pine showed higher plasticity than mountain pine for all architectural and morphological traits analysed, having higher adaptive capacity to a changing environment. Conclusions: Our results support the prediction of future biome changes in Pyrenean sub-alpine forests as silver fir and Scots pine may find appropriate conditions for colonizing mountain pine-dominated stands due to land-use change-related forest densification and climate warming-related temperature increases, respectively.This research was primarily supported by the Spanish Ministry of Science and Innovation via the DINAMIX project (AGL2009‐13270‐C02) and the Consolider‐Ingenio Montes project (CSD2008‐00040). The Spanish Ministry of Science provided Lluís Coll with support through a Ramon y Cajal contract (RYC‐2009‐04985), and the Spanish Ministry of Education provided support to Aitor Ameztegui through a predoctoral grant (FPU Programme ‐ AP2007‐01663). Christian Messier, Michael J. Papaik and two anonymous reviewers provided helpful comments on the manuscript. We also thank Sara Bastien‐Henri and Santiago Martín for valuable help during field sampling and laboratory processing and the Parc Natural de l'Alt Pirineu for kindly giving us permission to access the park and obtain sample data

    The time budget and feeding ecology of the pukeko (Porphyrio porphyrio melanotus, Temminck 1820) a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Zoology at Massey University

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    The annual and seasonal time budget and feeding ecology of pukeko Porphyrio porphyrio melanotus are described both as a composite day and diurnally. The study shows pukeko do not spend equal time in all activities in all habitats over the day, for each season or over the year. They spend by far the bulk of their time feeding (75-90%), and less time to attentiveness, bodily maintenance, and social encounters. However time allocated to all activities varies with habitat. By far most time is spent in dryland (pasture), and less in turn in rush margins, swamp and water. Bimodal activity patterns (dawn and dusk) are described for each season, whereas feeding effort is unimodal peaking in the mid to late afternoon. Direct sampling of an adjacent population indicates pukeko gradually increase the length of tiller taken and quantity of ingesta consumed over the day. Pukeko do not peck at the same rate or feed at the same intensity in all habitats, at all times of the day, for each season or over the year - feeding fastest and most intensely in rush margin and mud areas, and slower and less intensely in dryland, swamp and water. However considering use of habitats over the year pukeko feed most intensively and extensively in dryland, but less in rush margin, mud, swamp and water. Feeding in the latter three habitats is linked notably with seasonal availability (and/or quality) of forage. Evidence indicates pukeko are able to gauge seasonally the availability (and/or quality) of forage, and allocate their feeding effort appropriately

    Populus tremuloides seedling establishment: An underexplored vector for forest type conversion after multiple disturbances

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    Ecosystem resilience to climate change is contingent on post-disturbance plant regeneration. Sparse gymnosperm regeneration has been documented in subalpine forests following recent wildfires and compounded disturbances, both of which are increasing. In the US Intermountain West, this may cause a shift to non-forest in some areas, but other forests may demonstrate adaptive resilience through increased quaking aspen (Populus tremuloides Michx.) dominance. However, this potential depends on ill-defined constraints of aspen sexual regeneration under current climate. We created an ensemble of species distribution models for aspen seedling distribution following severe wildfire to define constraints on establishment. We recorded P. tremuloides seedling locations across a post-fire, post-blowdown landscape. We used 3 algorithms (Mahalanobis Typicalities,Multilayer Perceptron Artificial Neural Network, and MaxEnt) to create spatial distribution models for aspen seedlings and to define constraints. Each model performed with high accuracy and was incorporated into an ensemble model, which performed with the highest overall accuracy of all the models. Populus tremuloides seedling distribution is constrained primarily by proximity to unburned aspen forest and annual temperature ranges, and secondarily by light availability, summer precipitation, and fire severity. Based on model predictions and validation data, P. tremuloides seedling regeneration is viable throughout 54% of the post-fire landscape, 97% of which was previously conifer-dominated. Aspen are less susceptible to many climatically-sensitive disturbances (e.g. fire, beetle outbreak, wind disturbance), thus, aspen expansion represents an important adaptation to climate change. Continued aspen expansion into post-disturbance landscapes through sexual reproduction at the level suggested by these results would represent an important adaptation to climate change and would confer adaptive forest resilience by maintaining forest cover, but would also alter future disturbance regimes, biodiversity, and ecosystem services.Ye

    A Neural Network Method for Efficient Vegetation Mapping

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    This paper describes the application of a neural network method designed to improve the efficiency of map production from remote sensing data. Specifically, the ARTMAP neural network produces vegetation maps of the Sierra National Forest, in Northern California, using Landsat Thematic Mapper (TM) data. In addition to spectral values, the data set includes terrain and location information for each pixel. The maps produced by ARTMAP are of comparable accuracy to maps produced by a currently used method, which requires expert knowledge of the area as well as extensive manual editing. In fact, once field observations of vegetation classes had been collected for selected sites, ARTMAP took only a few hours to accomplish a mapping task that had previously taken many months. The ARTMAP network features fast on-line learning, so the system can be updated incrementally when new field observations arrive, without the need for retraining on the entire data set. In addition to maps that identify lifeform and Calveg species, ARTMAP produces confidence maps, which indicate where errors are most likely to occur and which can, therefore, be used to guide map editing

    Economic Issues in the Management of Plants Invading Natural Environments: Scotch Broom in Barrington Tops National Park

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    Scotch broom (Cytisus scoparius, L.), is an exotic leguminous shrub, native to Europe, which invades pastoral and woodland ecosystems and adjoining river systems in cool, high rainfall regions of southeastern Australia. Broom has invaded 10,000 hectares of eucalypt woodland at Barrington Tops National Park in New South Wales, and is having a major impact on the natural ecology of the sub-alpine environment. It is extremely competitive with the native flora, retarding their growth and in many areas blanketing the ground and preventing growth of many understorey species in open forest areas. An active program to manage this invasion is being implemented by the National Parks and Wildlife Service. The management issues include whether eradication or containment is economically desirable, and when biological control is economically desirable. Management choices depend on the marginal costs of increments of government intervention, effects of uncertain budgets on the control of broom, choice of control measures and effects of uncertain values of biodiversity. These issues are addressed through the application of a detailed bioeconomic model of broom management.Scotch broom, economic issues, management issues, natural environments, bioeconomic model, Environmental Economics and Policy,

    Tourism Development Perspectives in the Putna – Vrancea Nature Park

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    During the last years tourism in natural environments noted an increase in demand from the part of touristy products consumers. The Vrancea mountain area, though having a divers touristy potential, is not very well known on the tourism market. The Putna – Vrancea Nature Park, recently established, has real odds to be included in touristy programs made by traveling agencies. This article present the possibilities of tourism development in the area so the good protection of the nature variety is still achieved, but with a minimalist influence on the environment and also beneficial for the local community.nature park, environment protection, environment education,tourism in natural environments

    Patterns of bryophyte and vascular plant richness in European subalpine springs

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    The diversity of spring habitats can be determined not only by local environmental conditions, but also by large-scale biogeographical effects. The effects can differ across various groups of organisms. We compared α-, β- and γ-diversity patterns of bryophytes and vascular plants of (sub)alpine springs in three contrasting mountain ranges: Alps (Switzerland), Balkans (Bulgaria), Western Carpathians (Slovakia, Poland). We used univariate and multivariate statistics to test for the effects of pH, conductivity, altitude, slope, mean annual temperature and annual precipitation on diversity patterns of both taxonomic groups and compared diversity patterns among the regions for particular pH and conductivity classes. We identified acidophyte and basiphyte, calcifuge and calcicole species using species response modelling. All regions displayed significant relationship between conductivity and α-diversity of vascular plants. Bulgaria showed the highest α-diversity of vascular plants for the middle part of the conductivity gradient. For both taxonomic groups, the β-diversity in the middle part of gradient was highest in Swiss Alps. The total species pool was lowest in Bulgaria. The percentage of basiphyte and calcicole species was highest in the Alps. In (sub)alpine springs, mineral richness was a better determinant of vascular plant α-diversity than pH, and the extent of the alpine area did not coincide with α-diversity. Observed inter-regional differences in diversity patterns could be explained by the different proportion of limestone bedrock and different biogeographic history. The differences in α-diversity between both taxonomic groups are presumably result of the different rates of adaptation processe
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