Tesis sobre el tema "Rain forest ecology Australia"
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1
Greenwood, David Robert. "The foliar physiognomic analysis and taphonomy of leaf beds derived from modern Australia rainforest". Title page, contents and abstract only, 1987. http://web4.library.adelaide.edu.au/theses/09PH/09phg8165.pdf.
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McDonald, M. Christine. "Ecosystem resilience and the restoration of damaged plant communities : a discussion focusing on Australian case studies /". View thesis, 1996. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030625.095246/index.html.
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Levy, Ruth. "Community structure of ants in Brunei rain forest". Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240586.
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Green, James J. "Fine root dynamics in a Bornean rain forest". Thesis, University of Stirling, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335307.
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Hausmann, Franziska. "The utility of linear riparian rainforest for vertebrates on the Atherton and Evelyn Tablelands, North Queensland /". Click here to access, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20050115.105740.
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Thesis (M.Phil.) -- Griffith University, 2004.Facsimile of the author's original dissertation. Pagination of document: x, 121 leaves. Includes bibliographical references. Also available online via the World Wide Web.
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Malvido-Benitez, Julieta. "The ecology of seedlings in Central Amazonian forest fragments". Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361691.
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Manokaran, N. "Population dynamics of tropical forest trees". Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 1988. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=59678.
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Brinkley, Nancy Jane. "Rain forest curriculum for upper elementary and middle grades". CSUSB ScholarWorks, 1996. https://scholarworks.lib.csusb.edu/etd-project/1267.
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Sheil, D. "The ecology of long term change in a Ugandan rain forest". Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318868.
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Wan, Ahmad Wan Juliana. "Habitat specialisation of tree species in a Malaysian tropical rain forest". Thesis, University of Aberdeen, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368534.
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This thesis investigates the relationship between spatial distribution of tropical trees and variation in edaphic factors, particularly soil nutrient supply, and tests the importance of interspecific differences in growth rates and foliar nutrient concentrations as determinants of habitat specialisation. The distribution of some tree species at Pasoh Forest Reserve, Peninsular Malaysia, was correlated with variation in soil properties, especially available P concentrations, on a 50 ha plot. Seeding relative growth rates were highest on the alluvial soils, which had higher available P than the shale-derived soils in the absence of nutrient addition. The effect of habitat variation (characterised in terms of their nutrient and water availability) on tree growth of 115 species was examined within and between species. Overall, differences in tree growth rates between habitats correspond to variation in the pattern of nutrient supply and not water availability. Despite significant differences in growth rates between habitat types for some of the species, the differences in tree growth were a poor indicator of habitat preferences of tree species as defined by bias in their spatial distribution. Foliar nutrient concentrations of habitat generalists and two kinds of habitat specialists (alluvial and non-alluvial specialists) were compared using phylogenetically controlled comparisons. Sign tests showed only one significant difference in mean foliar nutrient (N, P, K, Ca and Mg) concentrations between distribution categories. The distribution of the differences in foliar mg concentrations between habitat generalists and alluvial specialists was significant at P < 0.05 and suggested that Mg concentrations were significantly greater in the habitat generalists. These results suggest that foliar nutrient concentrations are unlikely to explain differences between species in their habitat associations with respect to soil types at Pasoh.
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Poels, R. L. H. "Soils, water and nutrients in a forest ecosystem in Suriname". Wageningen : Agricultural University, 1987. http://catalog.hathitrust.org/api/volumes/oclc/23819734.html.
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Brown, N. D. "Dipterocarp regeneration in tropical rain forest gaps of different sizes". Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279886.
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Walker, Jonathan S. "Feeding ecology and rarity of frugivorous birds in tropical rain forest". Thesis, Manchester Metropolitan University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.400944.
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Kennedy, Donald Niall. "The role of colonising species in the regeneration of dipterocarp rain forest". Thesis, University of Aberdeen, 1991. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU548037.
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Regeneration of colonising species following disturbance of primary tropical rain forest in Malaysia was studied in artificial gaps ranging in size up to 30% canopy openness. Effects of gap size on soil temperature and water status were investigated. Spatial variation in density and composition of the soil seed bank beneath undisturbed forest was assessed by germination from soil samples, and seed rain was sampled using seed traps. Seed germination, seedling survival and seedling growth were monitored for two years in gaps and beneath intact canopy. Effects on colonisation of gap size, disturbance to microsite and competition from advance regeneration were studied. Maximum soil temperatures increased with gap size but minimum temperature was unaffected. Soil water content showed no relationship with gap size, but might be higher in gaps than forest after dry periods. Primary forest soil seed bank density was very high (mean 1904 seeds m-2). Climbing shrubs/lianes contributed approximately 75% of seedlings and 50% of taxa. Trees accounted for about 25% composition of taxa, but only 15% of seedlings. Soil seed bank composition differed little among primary forest sites. Similarities in composition between one site and secondary forest possibly reflected recent disturbance. Current seed rain intensity was low, very variable, and not consistently different between gaps and closed forest. Germination in the two years after gap creation was < 5% of the soil seed bank, and appeared greatest in medium-sized gaps. Most germination and accession of new taxa occurred in year one, but both continued at low levels during year two. Ordination analysis suggested that some colonising species regenerated only in large gaps. Both exposure and scarification of the soil increased germination, but had no consistent effects on seedling survival or growth. Competition from advance regeneration was potentially important, increasing mortality and reducing maximum growth rate among colonising seedlings.
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Liston, Katharine Ann. "Impacts of environment on dipterocarp seedlings : insect herbivores, gaps and forest type in a Malesian tropical rain forest". Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369932.
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Lambert, Frank R. "Fig-eating and seed dispersal by birds in a Malaysian lowland rain forest". Thesis, University of Aberdeen, 1987. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU010096.
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This study investigates avian fig-eating and Ficus seed dispersal in a patch of lowland rainforest at Kuala Lompat, Peninsular Malaysia, in the period March 1984 to April 1987.Of 38 Ficus species identified in c.2 km2 of forest, 29 possessed seeds primarily dispersed by birds. A phenological study of these species showed that figs were available in every month, and that the Ficus community exhibited distinct aseasonal fruiting rhythms. Nevertheless, crops of large figs (>25mm mean dimension) were rare, with only 13--16 large-fruited fig-patches per km2 of forest per year. The 60 bird species which ate figs at Kaula Lompat partitioned the fig resource according to fruit size, even though the soft nature of figs enabled birds of all sizes to feed on figs of all sizes. All birds, except some pigeons, rapidly defaecated ingested Ficus seeds. Treron pigeons were specialised fig-seed predators, and were found to eat large proportions of some fig crops; c.30% in one studied fruiting. Radiotracking and observations of foraging birds showed that many species stayed close to large fruit patches. As a consequence of this behaviour, and rapid gut-passage rates for Ficus seeds, seed shadows of bird-dispersed Ficus are anticipated to be leptokurtic. The most important Ficus seed dispersal agents, in terms of long distance dispersal, are predicted to be the larger, specialised frugivorous birds. Bird-dispersed Ficus at Kuala Lompat were all epiphytic species, growing predominantly on large commercial timber trees. Selective logging of lowland forest is therefore predicted to severely deplete the density of bird-dispersed Ficus, especially those species with large figs. Birds particularly dependent on such figs, such as Treron capellei and some of the hornbills, are severely threatened by such practices. Recommendations are made to promote the survival of these vulnerable bird species.
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Mitchell, Thomas Carly. "The ecology of Macaranga (Euphorbiaceae) trees in primary lowland mixed Dipterocarp forest, Brunei". Thesis, University of Cambridge, 1994. https://www.repository.cam.ac.uk/handle/1810/251702.
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Cunningham, Shaun Cameron 1971. "Comparative ecophysiology of temperate and tropical rainforest canopy trees of Australia in relation to climate variables". Monash University, Dept. of Biological Sciences, 2001. http://arrow.monash.edu.au/hdl/1959.1/9040.
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Barrett, Eamonn Bernard Michael. "The ecology of some nocturnal arboreal mammals in the rain forest of Peninsular Malaysia". Thesis, University of Cambridge, 1985. https://www.repository.cam.ac.uk/handle/1810/250856.
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Villela, Dora Maria. "Nutrient cycling in a monodominant and other rain forest types on Maraca Island, Brazil". Thesis, University of Stirling, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296770.
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Gibbons, James M. "Water relations, phenology and drought adaptation of understorey trees in tropical lowland rain forest". Thesis, University of Stirling, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298566.
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Scholtz, Olivia Ingrid. "Inter-continental patterns in the fine-scale spatial ecology of rain forest termites". Thesis, University of Plymouth, 2010. http://hdl.handle.net/10026.1/293.
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In this thesis I describe fine-scale spatial patterns in rain forest termites, from the colony to the assemblage level, sampled from one hectare plots in Central African and South East Asian lowland rain forest. By so doing the ecological interactions that structure this functionally important and abundant soil community were identified. The African termite assemblage, dominated by soil-feeding termites, saturated the upper soil profile (collected from 90% of soil pits). In contrast termites were collected from <50% of soil pits in Asia, with this difference reflecting the lower species densities and abundances of soil-feeding termites in Asian forests. Territoriality and inter-specific competition was shown to be important between colonies of soil-feeding species in the African plot. The termite assemblages were spatially associated with several environmental properties. However these could not explain the spatial patterns in the functional components of the assemblages. Wood-feeding termites were highly patchily distributed, due to the heterogeneous nature of their food material, but also due to possible competitive interactions for this. Humus-feeding termites were homogenously structured, due to the continuous nature of soil as their feeding and nesting material. True soil-feeding termites, unique to the African assemblage, were heterogeneously distributed despite the equally continuous nature of their feeding and nesting material. This structure may arise from facilitative interactions, such as co-operative defence against ant predation which may be intense in African systems, or through the transfer of soil material at different stages of decomposition. Competition for space is apparent in both regions, both at the colony level among soil-feeding genera, and between aggregations of functional groups. Positive and negative biotic interactions, operating at various spatial and functional scales, appear to be important in influencing how assemblage composition is spatially structured. If indeed facilitation is important in maintaining the taxonomic and functional diversity in termite assemblages, it would be valuable to confirm the mechanism(s) that drives this (i.e. predation and/or food transfer), as these may then influence ecosystem stability.
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Turner, Russell Sean School of Biological Earth & Environmental Science UNSW. "An airborne Lidar canopy segmentation approach for estimating above-ground biomass in coastal eucalypt forests". Awarded by:University of New South Wales. School of Biological, Earth and Environmental Science, 2006. http://handle.unsw.edu.au/1959.4/27362.
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There is growing interest in airborne lidar for forest carbon accounting and precision forestry purposes. Airborne lidar systems offer a cost-effective, versatile, operationally flexible and robust sampling tool for forest managers. The objective of this study was to develop and test lidar canopy surface enhancement and segmentation processes for estimating dominant above-ground biomass (DAB) in a harvested eucalypt forest on the Central Coast of New South Wales (Australia). The Crown Infill, Trim and Smooth (CITS) process, incorporating a series of filters, algorithms, and selective multi-stage smoothing, was used to enhance lidar canopy surfaces prior to segmentation. Canopy segmentation was achieved using a vertical crown template approach termed the Spatially and Morphologically Isolated Crest (SMIC) process. SMIC delineates dominant tree crowns by detecting elevated crown crests within a 3D lidar canopy surface. Consolidated crown units constitute the basic sampling, analysis and reporting units for wall-to-wall forest inventory. The performance, sensitivity and limitations of these procedures were evaluated using a combination of simulated forest models and actual lidar forest data. Automated crown polygons were used as a sampling template to extract dominant tree height values which were converted to DAB estimates via height-to-biomass relationships derived from field survey and on-site destructive sampling. Results were compared with field based tree height and biomass estimates. Compared against a manually derived crown map from a 2ha field plot, canopy segmentation results revealed a producer???s accuracy of 76% and overall accuracy of 67%. Results indicated a trend toward greater crown splitting (fragmentation) as trees increase in age, height, stem diameter and crown size. Extracted dominant tree height values were highly correlated with ground survey height estimates (r2 0.95 for precision survey and r2 0.69 for standard survey). There was also no significant difference between SMIC and manual crown height estimates. SMIC units overestimated ground-based DAB by 5%; this increased to 36% with the inclusion of segmentation errors. However, SMIC estimation of total plot above-ground biomass (AGB) was within 9% of the ground-based estimate. Results are encouraging considering the mixed-species, multi-aged composition of the forest, and the combined effects of SMIC segmentation and lidar height errors.
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Fishlock, Victoria L. "Bai use in forest elephants (Loxodonta africana cyclotis) : ecology, sociality & risk". Thesis, University of Stirling, 2010. http://hdl.handle.net/1893/2758.
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Forest elephant (Loxodonta africana cyclotis) sociality is relatively little-studied due to the difficulties of making direct observations in rainforests. In Central Africa elephants aggregate at large natural forest clearings known as bais, which have been postulated to offer social benefits in addition to nutritional resources. This thesis explores the role of these clearings as social arenas by examining bai use within three main themes; ecology, sociality and risk factors. Seasonal changes in elephant use of the Maya Nord bai (Republic of Congo) are described, along with the demography of the visiting population. Elephant visit rate was highly variable; the number of elephants using Maya Nord in an observation day ranged from 0 to 117 animals. This variability was unrelated to local resource availability and productivity suggesting that bai use occurs year round. Elephants in Odzala-Kokoua do not show high fidelity to a single clearing; 454 elephants were individually identified and re-sighted an average of 1.76 times (range 1-10) during the twelve month study period. Previous bai studies have yet to quantify how elephants associate with one another within the bai area. This study examines socio-spatial organisation and associate choice using two measures of association within the 0.23 km2 bai area; aggregations (all elephants present in the clearing) and parties (elephants spatially co-ordinated in activity and movement) and distinguishes these from parties that range together (i.e. arrive and leave together). Social network analyses (SocProg) were used to describe inter- and intra-sexual multi-level organisation in the bai environment, and to illustrate the non-random nature of elephant aggregations and parties. Bais were shown to function as social arenas; female elephants showed active choice of certain associates and active avoidance of others when creating parties, whereas males were less discriminatory. Parties formed in the clearing (mean size= 3.93, SE= 0.186) were larger than ranging parties (mean size= 2.71, SE= 0.084) and elephants stayed for 50% longer in the clearing when they associated with individuals from outside their ranging party. Inter- and intra-sexual relationships were maintained within the clearing, and these are suggested to offer elephants essential opportunities for social learning. The patterning and nature of the relationships observed at the Maya Nord clearing indicates that forest elephants use a fission-fusion social structure similar to that of savannah elephants (Loxodonta africana africana); relationships are significantly structured by age- and sex- and underpinned by individual identity. Old experienced females hold key roles for forest elephants, and male relationships are superimposed on the network of female associations. Odzala-Kokoua elephants use bais to maintain their social relationships despite being highly sensitive to the anthropogenic risks involved in using these open areas. The results of this study suggest that forest and savannah elephants lie on the same social continuum, balancing social “pulls” to aggregate against the ecological “pushes” that force groups to fission. Previous models of savannah elephant sociality construct levels of association and social complexity upwards from the basic mother-calf unit (e.g. Wittemyer & Getz 2007). My results suggest that it may be more appropriate to consider elephant sociality and associations as in dynamic equilibrium between social and ecological influences acting at all levels of grouping, and to explicitly test how these underlie the opportunity costs that elephants are willing to pay in order to maintain social groupings.
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Morris, Michael William. "Amazopoly a game of survival in a tropical rain forest". CSUSB ScholarWorks, 1996. https://scholarworks.lib.csusb.edu/etd-project/34.
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Pfrommer, Albrecht. "Seed dispersal ecology of Leonia cymosa (Violaceae) in the rain forest of Eastern Ecuador". kostenfrei, 2009. http://www.opus-bayern.de/uni-wuerzburg/volltexte/2009/3712/.
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Dore, David William Biological Earth & Environmental Sciences (BEES) UNSW. "Application of simple physiological growth models to coastal eucalypt regrowth forests in New South Wales". Awarded by:University of New South Wales. Biological, Earth and Environmental Sciences (BEES), 2006. http://handle.unsw.edu.au/1959.4/26200.
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This thesis explores issues relating to the application of physiological-process models (???process models???) of forest growth to mixed species, mixed age forests, in particular the coastal blackbutt forests of New South Wales. Using a dataset provided by State Forests of New South Wales (Carter 1994 unpubl.) a numeric description of the forest was developed and stand-level parameters of interest were derived, in particular the plot by plot stemwood volume growth from 1975 to 1999. The amounts of harvested volume, volume that died and volume that grew into the measurement population were identified separately, and several different means of accounting for volume change over time were investigated. A method for quantifying the impact of harvesting and other silvicultural practices on the growth of the forest was developed and programs were written to convert the stand-level summary of the harvest impact into a semi-random selection of trees that would be ???harvested??? from the database under the set of silvicultural assumptions (Dore et al. 1999). A number of process models were investigated and reviewed before selecting one particular model, SUSTAIN (Dewar 1997) for adaption to these forests. This model is a relatively simple process model with a small number of input parameters. The model was adapted so that it could be used to compare the SUSTAIN estimate of growth with the growth of an individual stand of trees in the Kendall Forest Management Area, between Wauchope and Taree on the mid-north coast of NSW. To improve the accuracy of the prediction of growth by SUSTAIN, a method of re-setting the state of the stand to the actual condition at the time of remeasurement was developed. In addition, the SUSTAIN model was extended to enable two separate levels of canopy to be described and grown separately. Ultimately the model was only partially successful in mirroring the growth predicted by the empirical data. Its partial success is attributed primarily to the difficulties associated with correctly determining the allocation parameters used by the model to assign net photosynthate to the roots, foliage and stemwood. The nature of the change in allocation parameters when the forest stand is disturbed by harvest or fire needs further investigation.
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Havel, J. J. "Ecology of the forests of south western Australia in relation to climate and landforms /". Access via Murdoch University Digital Theses Project, 2000. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060815.114944.
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Valencia, Niels. "Ecology of forests on the western slopes of the Peruvian Andes". Thesis, University of Aberdeen, 1990. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=128343.
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Dry cloud forests on the western slopes of the Peruvian Andes were mapped from aerial photographs, 306 stands being recorded from 4o50'S to 12o47'S. The frequency and area of these stands, as well as most parameters analyzed in the eight sample sites, show a steep decreasing latitudinal trend and are strongly correlated with the latitudinal rainfall gradient. The mean area of the forest stands decreases from 115 ha in northern Peru to 42 ha in central Peru. The number of species recorded decreases along the study area from 52 to 13 and there is a well defined latitudinal sequence of species. Mean density and basal area per hectare of stems ≥10 cm gbh decreases from 2995 individuals and 79.91 m^2 in the north to 500 individuals and 17.27 m^2 in central Peru. The vertical structure is similar throughout the study area, emergent trees reaching on average 22 m and the main canopy 12 m in the north and 13 m and 7 m respectively in central Peru. Regeneration is very active in northern Peru. Juveniles have been found for a high proportion of species, including all common ones, and most species show a logarithmic decline in number of stems with increasing girth. There is a steep decreasing trend towards central Peru, where few species regenerate, mostly shrubs. The pattern found may be the result of the combined effect of grazing and a climatic change towards drier conditions evidenced in the regeneration pattern of most sites.
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Cornelius, Cintia. "Genetic and demographic consequences of human-driven landscape changes on bird populations the case of Aphrastura spinicauda (Furnariidae) in the temperate rainforest of South America /". Diss., St. Louis, Mo. : University of Missouri--St. Louis, 2006. http://etd.umsl.edu/r1821.
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Sizer, Nigel Christopher. "The impact of edge formation on regeneration and litterall in a tropical rain forest fragment in Amazonia". Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241207.
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Zipperlen, Simon Weston. "Ecophysiology of tropical rain forest seedlings (Dipterocarpaceae) : growth, gas-exchange and light utilisation in contrasting light environments". Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264643.
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Kariuki, Maina. "Modelling dynamics including recruitment, growth, and mortality for sustainable management in uneven-aged mixed-species rainforests". Connect to this title online, 2004. http://epubs.scu.edu.au/theses/27/.
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Rhind, Susan Gaye. "Ecology of the brush-tailed phascogale in jarrah forest of southwestern Australia". Thesis, Rhind, Susan Gaye (1998) Ecology of the brush-tailed phascogale in jarrah forest of southwestern Australia. PhD thesis, Murdoch University, 1998. https://researchrepository.murdoch.edu.au/id/eprint/52136/.
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This study investigated the ecology of the marsupial brush-tailed phascogale (Phascogale tapoatafa; phascogale) in jarrah forest of Western Australia (WA). The thesis provides a descriptive account of the species' population dynamics, the phascogale’s size and growth, foraging ecology and nesting behaviour. The main work was undertaken between 1992-1995 and information was gathered by capture and by using radiotelemetry. The availability of food sources and refuge sites was examined and the species' immediate response to a logging operation was investigated. On a broader scale, the taxonomy of phascogales in WA was reviewed and their past and present distributions were explored by modelling and examination of museum records. The species has previously been subject to only one detailed study and this was undertaken in the State of Victoria.
Both similarities and differences were observed between the phascogales in WA and Victoria. Many of the differences appeared to have a nutritional basis. Phascogales are primarily arboreal insectivores and some of the invertebrates most commonly found in scats and stomachs were not abundant on trees. Nectarivory was very rarely observed (cf. Victoria). While phascogales are generalists in diet, they clearly show preferences for certain foods. The strongly seasonal climate in the southwest (long dry summers and wet winters) and the lack of diversity in tree species and low nectar availability probably limit food for WA phascogales. The dispersed nature of tree invertebrates and the apparent scarcity of some preferred prey, such as beetles, possibly explain the exclusive and often large size of female territories.
Phascogales in the study area were smaller and less sexually dimorphic than those in Victoria. Males were 30%, and females 20%, less in weight than those in Victoria. They were similarly smaller in skeletal size. Overall size was also found to vary' between habitat type and between years. In a year of drought phascogales did not achieve typical body size with mature males in that year weighing an average 25% less than usual. The evidence strongly suggests that annual and local availability of food is a major determinant of body size and growth.
Such variability in food availability may also be the evolutionary basis behind the litter sizes of WA phascogales. These are smaller than those in Victoria (mode WA = 6, Victoria = 8). The timing of major life-history events was as described for Victorian phascogales, although births occur a little later in the year. All males died at the end of the single annual breeding season (male semelparity) and young took some five to six months to raise to weaning. Some females survived to breed in a second year but the number encountered was low. The toll of lactation probably reduces lifespan and females were often in poor condition at late lactation and maximum maternal effort appears selectively invested in the first litter.
Typical of the semelparous species, females initially tried to raise as many young as they have teats. However, there was variation in litter sizes among females. The basis for this was anatomical as females had six, seven or eight teats. Such variation occurred throughout the study area, within litters and appears a State-wide phenomenon. Except in a hybrid Antechinus population, there appears to be no marsupial precedent for intrapopulation and intralitter variation in teat number. In such a strongly selected trait, it is speculated that such variation could only persist if the environment was spatially and/or temporally unstable in terms of food availability. There was no evidence that reduction in teat number was a direct trade-off that improved the chance of surviving to breed on a second occasion, but data were limited. The teat trait is presumably under genetic control and the promiscuous mating behaviour of phascogales may contribute, via multiple paternity, to the intralitter variability observed.
In the year of drought litters were significantly female biased. Neither sex were sexually dimorphic until they began foraging for themselves, therefore such bias was unlikely to reduce maternal stress during the drought conditions. The adaptive advantage of the bias was undetermined, but current literature indicates that such bias occurs at conception. However, female offspring probably have better post-weaning survival than males.
Examination of refuge requirements showed that natural nest sites were located in tree hollows. The profile of the trees chosen agree with most studies on hollow-nesting species. There was no apparent preference for particular tree species but there was a preference for nesting in older and senescent or dead trees. Females with dependent young showed particular preference for these trees' forms. However, once a tree was used, no tree characteristics measured were predictors of the tree being used on further occasions. Excluding females with young, phascogales typically spent 2-5 days nesting in the one refuge before moving to another. Females moved between alternative refuges more than males and home range maintenance is proposed to account for the difference (males were not territorial cf. females). For both sexes, parasite avoidance might account for the generally low level of nest-site fidelity. Individuals were estimated to use around 27 (males) and 38 (females) different nest-sites during one year of adult life. The parameters of hollows examined showed a preference for using hollows with small entrances. More than predator avoidance, interspecific competition for hollows may explain such selectivity.
Following the year of drought, communal nesting was common in autumn and winter. This was in marked contrast to data gathered early in the study and to the nesting behaviour of Victorian phascogales. Communal nesting was probably an energy conserving strategy adopted to compensate for unusually small body size. This behaviour may have been a single year event. However, as phascogales in the area are normally much smaller in body mass than those studied in eastern Australia, they may tend to nest communally in winter or when under conditions of hardship.
The immediate response of phascogales to logging was examined. Those affected continued to travel through and feed in the logged areas, which reinforces the concept of high site fidelity among animals. Phascogales were commonly found feeding among ground debris in cut areas indicating flexibility in foraging mode. With rare exceptions they ceased nesting in trees in the logged parts of their territories and confined such nesting to surrounding uncut forest. This suggests that the forestry practice of retaining a select number of hollow-bearing trees/ha may be insufficient to meet the species' refuge requirements in logged areas. Of concern is that currently unlogged sections in logged forest can be cut within 10-20 years yet trees take some 200 years to develop hollows. Additionally, the value of young regrovvth as a food source to this species is questionable. The study highlights the concerns that many scientists have regarding the preservation of hollow-nesting fauna in areas that are impacted by logging.
A revision of the species taxonomy (including the subspecies P. t. pirata) indicates that southern WA phascogales warrant subspecies status. Differences in basiacranial features were found between the regional groups in Australia. However, the issue of long-term geographic and reproductive isolation is perhaps the greater argument for suggesting subspecific status for WA phascogales. This is currently being examined using mitochondrial DNA techniques. This will provide not only a DNA profile of similarities and presumed differences between WA and southeastern phascogales, but will give an estimation of the time that the two groups have been separated.
A modelling exercise undertaken to examine the potential past distribution of WA phascogales showed that climatic conditions favourable to this species are found throughout the southern part of WA. For many of these areas there are no records of phascogales although a single historical work (1909) indicated that they were present in these areas. At that time they were apparently already extinct in some areas and dying out in others. A survey of the northern jarrah forest and a few other areas (by using nestboxes) failed to detect phascogales. The population examined during this study was therefore quite unusual in density, as phascogales were readily found in nestboxes. A myriad of factors culminating in low feral predation in the area seems the most likely explanation for the high densities observed. The conservation status of phascogales in areas other than the study region requires examination. Predation by exotic predators might account for the species' rarity, but food appears a generally limiting factor for phascogales and processes that alter habitat productivity may significantly impact this species.
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Ilstedt, Ulrik. "Soil degradation and rehabilitation in humid tropical forests (Sabah, Malaysia) /". Umeå : Swedish University of Agricultural Sciences, 2002. http://diss-epsilon.slu.se/archive/00000233/.
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Thesis (doctoral)--Swedish University of Agricultural Sciences, 2002.Abstract inserted. Appendix reprints four papers and manuscripts co-authored with others. Includes bibliographical references. Also partially issued electronically via World Wide Web in PDF format; online version lacks appendix.
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Tobón, Marin Conrado. "Monitoring and modelling hydrological fluxes in support of nutrient cycling studies in Amazonian rain forest ecosystems". Wageningen, The Netherlands : Tropendos Foundation, 1999. http://catalog.hathitrust.org/api/volumes/oclc/43455503.html.
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Ross, Karen School of Biological Earth & Environmental Sciences UNSW. "Effects of fragmentation and disturbance on a eucalypt open-forest plant community in south-eastern Australia". Awarded by:University of New South Wales. School of Biological, Earth and Environmental Sciences, 2005. http://handle.unsw.edu.au/1959.4/22454.
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This study documented effects of fragmentation and disturbance on a coastal eucalypt dry open-forest plant community at Port Stephens-Myall Lakes, south-eastern Australia. The study evaluated the relative influence of fragment size (range <1-75ha), fragment or edge age (< 1-25y), time since fire (5-25y) and anthropogenic disturbance (minor, major) on microclimate, native plant species richness and weed invasion. Plots were sampled for native and exotic species richness per 25 m2 and edge transects for light, soil moisture, soil temperature, vegetation structure, native species richness and exotic species richness and cover. Depths of edge influence (DEI) were all < 20m inside the forest edge. Younger edge zones were lighter, had hotter and drier soils and more native species than forest interiors. Older edge zones were shadier, had warmer and moister soils and fewer native species than forest interiors, due to vegetation thickening in the edge zone. Light and soil moisture followed linear or monotonic edge-to-interior gradients in younger edges, but more complex patterns in older edges. Soil-temperature DEI decreased with increasing edge age. Fragment size had little influence on edge effects, but those for light developed more rapidly in smaller fragments, and recent fire was associated with reduced richness in edge zones of smaller fragments. Both anthropogenic disturbance and fire enlarged DEI for native species richness. Major anthropogenic disturbance coupled with fragmentation produced a stronger and more immediate loss of native species than fragmentation alone. Small fragments with minor disturbance had fewer native species per 25 m2 than larger fragments, but only after >10y since fragmentation. Analysis of forest interior portions of transects revealed that edge effects, and possibly disturbance, were largely responsible for this loss of native species with time, rather than effects of area. Despite a viable soil seed bank in fragments and the surrounding matrix, weed invasion in fragments was minimal. Exotic species were concentrated in edge zones, and were promoted by major anthropogenic disturbance within fragments. Results were highly dependent on fragment or edge age, and external influences of fragmentation (edge effects and disturbance), were more important than biogeographic (area-driven) factors. Impacts of fragmentation were compounded when combined with disturbance.
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Richards, Michael. "Economic incentives for the sustainable management and conservation of tropical forests". Thesis, University of South Wales, 2007. https://pure.southwales.ac.uk/en/studentthesis/economic-incentives-for-the-sustainable-management-and-conservation-of-tropical-forests(eb11e629-42d7-4fbf-924c-769ac6a42471).html.
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This PhD by Publication traces through 13 of my publications on economic incentives for forest management and conservation in tropical countries (with a regional bias towards Latin America), including several papers focused on participatory forest management or community-based conservation. The papers show how my thinking has evolved from a focus on market and nonmarket incentives, to an increasing emphasis on governance and regulatory incentives in explaining stakeholder behaviour to the forest resource, as well as the equity impacts. They reveal that positive incentives and win-win (environmental and poverty reduction) outcomes will only emerge when the underlying market, policy and institutional failures are tackled. Because of their public good values, the survival of tropical forests is contingent on the actions of the international community and governments. Sustainable forestry, therefore, depends on a combination of domestic governance progress to control illegal logging and the rent-seeking powers of vested interest groups, global governance regulations which create markets for environmental services, secure property rights for resident stakeholders and extra-sectoral policies that moderate land use opportunity costs. The current main hope for tropical forests is 'avoided deforestation' since this will need to tackle the forest governance problems and underlying multi-sectoral drivers of deforestation if it is to be successful. It represents a balanced market (payments for ecosystem services) and supply-side (improved governance) response to what is essentially a 'public goods' management problem, but will need to overcome some major political economy challenges.
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Havel, Jaroslav J. "Ecology of the forests of south western Australia in relation to climate and landforms". Murdoch University, 2000. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060815.114944.
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This thesis sets out to test the hypothesis that the vegetational patterns in the forested region of south western Australia are primarily determined by the interaction of climate and landform.
The region is an area of 4.25 million hectares subject to recent agreement between the Commonwealth of '4ustralia and the state of Western Australia regarding long-term
protection and management of forest (Regional Forest Agreement).
The climate of the South Western forest region is warm temperate and summer dry, matching Koeppen's category Cs, usually described as mediterranean.
The dominant geological features of South Western Australia are crystalline and sedimentary plateaus and coastal plains. They are subject to a complex process of
weathering, denudation and re-deposition, which is the key determinant of landforms and soil patterns. Deep but infertile soils are prevalent.
The dominant vegetation formation of the region is open forest, which reduces to woodland in the drier north and east and increases to tall open forest in the moister
south. Floristically the vegetation is very rich, comprising over 3000 vascular plant species. The richness resides in the forest and woodland understorey and in the
shrublands, heathlands and sedgelands of edaphically extreme sites. By comparison, the forest overstorey is very simple, only one or two species being often dominant
over extensive areas.
The validation of the hypothesis that climate and landforms determine the vegetation patterns in South Western Australia is carried out in the following stages:
1) review of past studies of vegetation patterns in relation to the underlying environmental factors, relating them to one another in terms of floristics,
2) conversion of landform and climate maps for the region into vegetation maps by means of toposequences, that is gradients of topography, soils and vegetation within individual landform/climate combinations,
3) production of two sets of vegetation maps, namely six maps of vegetation complexes (1:250,000) and one map of vegetation systems (1:500,000),
4) testing the predictive capability of the resulting maps by comparing the occurrences of individual species of trees, shrubs and herbs predicted by map
legends, with their records in FloraBase, the geographic information system of the Western Australian Herbarium, and
5) using the outcomes of the above studies to assess the validity of the hypothesis.
Because the above hypothesis is so broad, it will be considered under seven headings:
a) nature of the vegetation patterns (continuum or discrete categories),
b) regional effect of climate and local effect of landform,
c) effect of landforms on soil depth, texture and fertility,
d) joint effect of slope, soil depth and texture on water balance,
e) interactive effect of landform and climate on vegetation patterns,
f) response of individual species to climate and landform, and
g) effect of other factors of environment, such as fire, on vegetation patterns.
The subsidiary hypotheses are defined in Chapter 5.
It is concluded that the vegetation of the region forms a lumpy continuum from the wet south west to the dry north east. Within that broad continuum there are localised
continua from waterlogged sites in depressions to drought-prone sites on steep stony slopes. However, the dominant vegetation of the region is open forest on plateau
uplands with deep infertile soils.
Although climate and landforms have a strong effect on vegetation patterns, they do not determine all vegetation patterns directly. Some tree species have ranges of
occurrence that are too broad for that, and others have ranges that are too restricted.
A more probable explanation is that climate and landforms, together with fire, set the stage on which the interplay of species takes place and determines the structure and
composition of the vegetation. An attempt is made to predict the likely effect of climatic changes on vegetation patterns.
The applicability of the methodology developed to the mapping of other regions, especially the adjacent ones, is examined. A review is made of how the products of
the study, in particular the maps, are currently being used, and suggestions are made how they could be used in the future.
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Beckwith, Robaire Stephen. "The ecology and behaviour of the Javan black langur, in lower montane rain forest, West Java". Thesis, University of Cambridge, 1995. https://www.repository.cam.ac.uk/handle/1810/252001.
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Costanzo, Angela J. "A quantitative survey of riparian forest structure along the Quebrada Grande in La Cangreja National Park, Costa Rica /". Thesis, Connect to this title online, 2006. http://www.ranchomastatal.com/docs2/php5pk7ty%5FRiparianForestStructure%5FCostanzo.pdf.
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Ruzicka, Stepan. "Soil biological properties in damaged Picea abies (L.) Karst, ecosystems in Bohemia, Czech Republic". Thesis, University of East London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359993.
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McElhinny, Chris. "Quantifying stand structural complexity in woodland and dry sclerophyll forest, South-Eastern Australia /". View thesis entry in Australian Digital Theses Program, 2005. http://thesis.anu.edu.au/public/adt-ANU20060322.133914/index.html.
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Hausmann, Franziska y n/a. "The Utility of Linear Riparian Rainforest for Vertebrates on the Atherton and Evelyn Tablelands, North Queensland". Griffith University. Australian School of Environmental Studies, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20050115.105740.
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This study investigated the utility to vertebrates of upland linear riparian rainforest fragments on the Atherton and Evelyn Tablelands in the Australian Wet Tropics region, north Queensland. Similar linear fragments were selected, that varied in forest age and their connectivity to large areas of continuous forest:- (connected primary (N=6), isolated primary (N=5), connected secondary (N=6) and isolated secondary (N=7)). Primary sites had either never been cleared or only subject to selective logging, while secondary forest had been completely cleared and allowed to regenerate for at least 30 years. These linear fragments were contrasted with riparian sites within continuous forest sites (N=6 to 7), which were situated in State Forest or National Parks, and sites within the cleared matrix (pasture, N=6). Vertebrates surveyed were birds, ground-dwelling mammals and reptiles, particularly leaf-litter skinks. All surveys were conducted between September and December in 2001 and/or 2000. Chapter 2 investigates the effects of forest age, isolation and structural vegetation features on bird assemblages within linear riparian fragments of rainforest. Bird surveys and structural vegetation assessments were conducted within connected and isolated primary and secondary linear fragments, and compared with those of continuous forest habitat (N=6) and pasture. There were strong effects of forest age; all three types of primary rainforest had higher values than secondary rainforest for most measured attributes of vegetation structure (including canopy height and cover; and frequency of large-diameter trees, lianes, epiphytes, strangler figs; and woody debris), but lower frequencies of tree ferns and thorny scramblers. Sites within primary rainforest also had a greater frequency of many bird species across different guilds of habitat, feeding and movement. Assemblages of rainforest-dependent birds showed an effect of isolation, although its strength was less than that of forest age. Isolated fragments of primary rainforest differed significantly from continuous primary rainforest in their rainforest-dependent bird species assemblages (and had lower species richness), and isolated fragments of secondary rainforest differed from those that were connected. There was a significant association between the species composition of rainforest birds and some measured vegetation parameters across all sites, but not within primary or secondary sites. Vegetation differences did not explain the lowered frequency of several species in isolated fragments. Limited dispersal seems unlikely to be a main cause, and causal processes probably vary among species. Specialist rainforest species endemic to the Wet Tropics region showed stronger responses to present-day rainforest age and fragmentation than those not endemic. Variation in nest depredation levels associated with rainforest fragmentation (edge effects) is examined in Chapter 3. Artificial nests were placed in the forest understorey at seven edge sites where continuous forest adjoined pasture, seven interiors (about one kilometre from the edge), and six primary linear riparian forest remnants (50-100 m wide) that were connected to continuous forest. Four nest types were compared, representing different combinations of two factors; height (ground, shrub) and shape (open, domed). At each site, four nests of each type, containing one quail egg and two model plasticine eggs, were interspersed about 15 m apart within a 160 m transect. Predators were identified from marks on the plasticine eggs. The overall depredation rate was 66.5% of 320 nests' contents damaged over a three-day period. Large rodents, especially the rat Uromys caudimaculatus, and birds, especially the spotted catbird Ailuroedus melanotis, were the main predators. Mammals comprised 56.5% and birds 31.0% of identified predators, with 12.5% of unknown identity. The depredation rate did not vary among site-types, or between open and domed nests, and there were no statistically significant interactions. Nest height strongly affected depredation rates by particular types of predator; depredation rates by mammals were highest at ground nests, whereas attacks by birds were most frequent at shrub nests. These effects counterbalanced so that overall there was little net effect of nest height. Mammals accounted for 78.4% of depredated ground nests and birds for at least 47.4% of shrub nests (and possibly up to 70.1%). The main predators were species characteristic of rainforest, rather than habitat generalists, open-country or edge specialists. For birds that nest in the tropical rainforest understorey of the study region, it is unlikely that edges and linear remnants presently function as ecological population sinks due to mortality associated with increased nest depredation. The use of linear riparian remnants by small ground-dwelling mammals and reptiles (mainly leaf litter skinks), is reported in Chapter 4. Site types were continuous rainforest, connected and isolated linear fragments of both uncleared primary rainforest and secondary regrowth rainforest. Mammals were also surveyed in pasture sites. Neither reptile species richness nor abundance varied significantly among site types. Although mammal species richness varied significantly between site types, with isolated primary sites containing highest species richness, overall mammal abundance did not differ significantly among site types. Pasture sites differed significantly from all rainforest sites in their mammal species composition, and were dominated by the introduced house mouse (Mus musculus). This species was absent from all rainforest sites, which were characterised by moderate abundances of bush rat/Cape York rat Rattus fuscipes/leucopus, fawn-footed melomys Melomys cervinipes and giant white-tailed rat Uromys caudimaculatus. None of these species varied significantly in abundance among site types, although the giant white-tailed rat showed a trend (P=0.09) for reduced abundance in isolated secondary sites. A single reptile species, the prickly forest skink Gnypetoscincus queenslandiae, occurred in sufficient numbers for individual analysis, and its abundance varied significantly among the forested site types, being less abundant in all linear fragments than in continuous forest sites. The utility of linear riparian rainforest for vertebrates appears to be species-specific and involves many factors. However, overall, species endemic to the Wet Tropics (which are hence of the highest conservation significance) appear to be the most sensitive to fragmentation. These species were most likely to show altered abundances or frequencies of occurrence due to isolation, forest age, and habitat linearity. The ecology of species within this group warrants further investigation within fragmented and non-fragmented regions of the Tablelands. For many other vertebrates examined in this study, there appears to be sufficient functional connectedness between remnants on the Tablelands to minimise the effects of fragmentation. Nevertheless, the lower density of many of these species in pasture may indicate that their long-term persistence within the fragmented rainforest areas could benefit from the maintenance or establishment of habitat linkages. Certainly, if the current rainforest vegetation cover were further reduced, or if the land use in the matrix became more intensive, the establishment of specific habitat linkages could become more important as existing dispersal routes could be lost. It also appears that nest depredation levels are unlikely to limit the value of linear rainforest remnants and other small rainforest remnants as breeding habitat for birds (at least for understorey-nesting species), relative to more intact rainforest, in the study region.
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Shrestha, Hari Ram. "Post-fire recovery of carbon and nitrogen in sub-alpine soils of South-eastern Australia /". Connect to thesis, 2009. http://repository.unimelb.edu.au/10187/6963.
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The forests of south-eastern Australia, having evolved in one of the most fire-prone environments in the world, are characterized by many adaptations to recovery following burning. Thus forest ecosystems are characterized by rapid regenerative capacity, from either seed or re-sprouting, and mechanisms to recover nutrients volatilized, including an abundance of N2 fixing plants in natural assemblages. Soil physical, chemical and biological properties are directly altered during fire due to heating and oxidation of soil organic matter, and after fire due to changes in heat, light and moisture inputs. In natural ecosystems, carbon (C) and nitrogen (N) lost from soil due to fires are recovered through photosynthesis and biological N2 fixation (BNF) by regenerating vegetation and soil microbes.This study investigated post-fire recovery of soil C and N in four structurally different sub-alpine plant communities (grassland, heathland, Snowgum and Alpine ash) of south-eastern Australia which were extensively burnt by landscape-scale fires in 2003. The amount and isotopic concentration of C and N in soils to a depth of 20 cm from Alpine ash forest were assessed five years after fire in 2008 and results were integrated with measurements taken immediately prior to burning (2002) and annually afterwards.
Because the historical data set, comprised of three soil samplings over the years 2002 to 2005, consisted of soil total C and N values which were determined as an adjunct to 13C and 15N isotopic studies, it was necessary to establish the accuracy of these IRMS-derived measurements prior to further analysis of the dataset. Two well-established and robust methods for determining soil C (total C by LECO and oxidizable C by the Walkley-Black method) were compared with the IRMS total C measurement in a one-off sampling to establish equivalence prior to assembling a time-course change in soil C from immediately pre-fire to five years post-fire. The LECO and IRMS dry combustion measurements were essentially the same (r2 >0.99), while soil oxidizable C recovery by the Walkley-Black method (wet digestion) was 68% compared to the LECO/IRMS measurements of total C. Thus the total C measurement derived from the much smaller sample size (approximately 15 mg) combusted during IRMS are equivalent to LECO measurement which require about 150 mg of sample.
Both total C and N in the soil of Alpine ash forests were significantly higher than soils from Snowgum, heathland and grassland communities. The ratio of soil NH4+ to NO3- concentration was greater for Alpine ash forest and Snow gum woodland but both N-fractions were similar for heathland and grassland soils. The abundance of soil 15N and 13C was significantly depleted in Alpine ash but both isotopes were enriched in the heathland compared to the other ecosystems. Abundance of both 15N and 13C increased with soil depth.
The natural abundance of 15N and 13C in the foliage of a subset of non-N2 fixing and N2 fixing plants was measured as a guide to estimate BNF inputs. Foliage N concentration was significantly greater in N2 fixers than non-N2 fixers while C content and 13C abundance were similar in both functional groups. Abundance of 15N was depleted in the N2 fixing species but was not significantly different from the non-N2 fixers to confidently calculate BNF inputs based on the 15N abundance in the leaves.
The total C pool in soil (to 20 cm depth) had not yet returned to the pre-fire levels in 2008 and it was estimated that such levels of C would be reached in another 6-7 years (about 12 years after the fire). The C and N of soil organic matter were significantly enriched in 15N and 13C isotopes after fire and had not returned to the pre-fire levels five years after the fire. It is concluded that the soil organic N pool can recover faster than the total C pool after the fire in the Alpine ash forests.
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Schaffer, Josef W. "Social behaviors of modern and indigenous peoples impacting the ecology of the Amazon rain forest in Brazil /". Click here to view, 2009. http://digitalcommons.calpoly.edu/erscsp/3.
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Thesis (B.S.)--California Polytechnic State University, 2009.Project advisor: William Preston. Title from PDF title page; viewed on Jan. 14, 2010. Includes bibliographical references. Also available on microfiche.
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Samsoedin, Ismayadi. "Biodiversity and sustainability in the Bulungan Research Forest, East Kalimantan, Indonesia : the response of plant species to logging". Thesis, University of Stirling, 2007. http://hdl.handle.net/1893/224.
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This study reports forest structure, regeneration and the soil properties from unlogged and logged forest in the Bulungan Research Forest, Malinau District, East Kalimantan, Indonesia. Four sites were compared by using four 1-ha replicate plots in each of primary forest (PF), 5, 10 and 30-yr old logged forest (LF-5, LF-10, LF- 30). The tree species composition differ among forest types, as it was shown that the mean value of similarity indices for all pairs were 0.215 (for the Jaccard index) and 0.353 (for the Sorensen index). The low values for similarities among forest types were most probably caused by low numbers of species shared between each forest type. Both correlation values, r = 0.023 for Jaccard index and r = 0.031 for Sorensen index, showed no strong correlation between the similarity index (C) and the distance between forest types. This supports the use of a chronosequence approach. A total of 914 tree species with ³ 10 cm dbh were recorded from 223 genera and 65 families. There were no significant differences in mean species numbers (166 – 180/ha) among treatments. Mean density of species was lower in LF-5 and LF-10 (501/ha) than in PF or LF-30 (605/ha and 577/ha); similarly to mean basal area (LF-5, 28.5 m2/ha; LF-10, 32.6 m2/ha) vs. PF (45.8 m2/ha) and LF-30 (46.9 m2/ha). Dead wood on the forest floor was significantly higher in LF-10 (75 m3/ha) than in the other treatments. Seedlings (< 2 cm dbh) of 1,022 species were recorded from 408 genera and 111 families. The mean number of tree seedling species ranged between 170-206; the mean density of seedlings was about two-fold lower in LF-10 (2790/ha) than in the other treatments. Saplings (>2 – 9.9 cm dbh) of 802 species belonged to 241 genera and 65 families. There was a high variability in species richness across treatments (89 – 191/ha), but not in stem numbers. The Dipterocarpaceae family was dominant in all treatments, followed by the Euphorbiaceae. The soils were acidic, low in nutrients and had low to very low fertility. Both primary and logged forest areas are marginal or not suitable for sustained production of plantation crops. Logging caused soil compaction in LF-30. Although in terms of number of species and trees, amount of BA, number of saplings and seedlings LF-30 appeared to have satisfied prescriptions for a second harvest, ecologically the forest is far from mature. The Indonesian Selective Cutting and Replanting (TPTI) system may need to be revised to a 35 – 45 year cycle to ensure long-term forest productivity in terms of not only timber but other goods and ecosystem services, the value of which are never quantified in monetary terms, but can be higher than the timber revenue.
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Castro-Herrera, Fernando. "Niche Structure of an Anole Community in a Tropical Rain Forest within the Choco Region of Colombia". Thesis, North Texas State University, 1988. https://digital.library.unt.edu/ark:/67531/metadc798407/.
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Ten species of anoles at Bajo Calima within the Choco of Western Colombia separate into two principal microhabitat groups: forest species, and those inhabiting openings and edges. The ten anoles further separate according to ground and vegetation dwellers. There is a relation at Bajo Calima between the number of anole species and vegetational structural diversity. Anole diversity within a given macrohabitat is by perch microsite/microclimate heterogeneity. These are the two major ecological dimensions along which similarity is limited or resources are partitioned.
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Cargill, Jeffrey. "Fate of Eucalyptus marginata seed from canopy-store to emergence in the northern jarrah forests of Western Australia: Research to help improve regeneration following shelterwood treatment". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2014. https://ro.ecu.edu.au/theses/1415.
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The establishment of seedling regeneration is a key process in and indicator of ecologically sustainable forest management. The availability of seed and the creation of a suitable seedbed are recognised as important factors limiting seedling recruitment. A silvicultural method commonly used across northern and eastern jarrah forest blocks is shelterwood cutting. The primary objective of treating jarrah forest to shelterwood is to promote seedling regeneration in areas lacking sufficient advanced growth. Despite the widespread and progressive implementation of the shelterwood method, its application in jarrah forest has shown varying degrees of success.
This thesis sought to investigate and better understand the roles of seed supply and seedbed condition in promoting successful seedling regeneration in shelterwood-treated jarrah forest. It addressed two questions from an ecological and management perspective. Firstly, could adequate seed supply and favourable seedbed conditions be effectively managed and produced in shelterwood-harvested coupes? Secondly, could adequate seed supply and suitable seedbed conditions be reliably produced to facilitate successful seedling regeneration following disturbance events, in this case post-harvest burning?
A major effort was dedicated to developing a more accurate and practical method of assessing seed crops in individual trees. The final model produced a high degree of predictability (R² = 0.85), while still maintaining a high level of practicality for field application, with three easily measured variables being used (stem diameter combined with subjective assessments of capsule clump density and capsule clump distribution). The refined model dramatically improved estimates of crown capsule numbers from the previous model, with the R² value increasing from 0.29 to 0.85.
The second major focus of the study was to assess the capacity of prescribed burns, under mild conditions, to produce seedbed conditions suitable for regeneration. Low intensity prescribed burns resulted in the production of suitable conditions for seedling regeneration; that is, leaf litter and understorey vegetation were reduced and ash beds were created. Ash bed production was heterogeneous within sites. This heterogeneity has been attributed to the capacity of low intensity prescribed burns to account for fine-scale variations in fuel quantity, continuity and condition.
Patterns of pre-burn aerial seed crop size and seed fall following low intensity prescribed burning were also assessed. Canopy capsule crops showed a high degree of spatial and temporal variability, both in terms of seed quantity and maturation. Such variability has been attributed to individual trees or groups of trees responding differently to localised climatic events and/or interspecific site factors at each stage of the flowering cycle. The main source of this variability was shown to be the numbers and spatial distribution of super trees; that is, trees defined as having a stem diameter >60 cm and >20 000 capsules. The average rate of seed fall increased substantially following prescribed burning under mild conditions. Postharvest burning under the mild conditions of the current survey did not result in en masse seed fall. Rather, peaks in seed fall were observed in the first few weeks post-burn, followed by low level falls throughout the following year. Sites burnt in spring showed a higher and more consistent release of seed in the first few weeks following fire, whereas seed fall after autumn burning was more sporadic.
The comparative and interactive roles that seed supply and seedbed conditions play in limiting recruitment of jarrah were also studied. Low seedling densities were recorded across all six burnt study sites. The fact that ample levels of post-burn seed fall produced such low seedling numbers suggested that adequate seed supply did not coincide with seedbed conditions suitable for mass seedling regeneration. Conditions favourable for seedling recruitment were highly variable within sites, since both seed supply and seedbed conditions were spatially heterogeneous. Fine-scale areas burnt to mineral soil showed an additive influence to the overwhelmingly dominant factor of seed supply on seedling recruitment. However, the capacity of low intensity burns to produce these seedbed conditions at a broad scale is limited.
Results of this study suggest that successful stocking of shelterwood-treated jarrah forest is not always achievable following a disturbance event, such as post-harvest burning under mild conditions. The chances of a large seed supply coinciding with broad-scale seedbed conditions favourable for mass germination, emergence and establishment appear to be low. Successful stocking of shelterwood-treated jarrah forest is more likely to be a longer term outcome achieved through episodic recruitment, when favourable environmental conditions coincide with optimal seedbed conditions. Such episodic recruitment strategies may be common in resource-limited systems such as jarrah forest and other dry eucalypt forest systems, where conditions controlling the regeneration niche are often variable and unpredictable.
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George, Amy Kathryn. "Eucalypt regeneration on the Lower Murray floodplain, South Australia". Connect to this title online, 2004. http://hdl.handle.net/2440/37706.
Texto completoResumen
Vegetation along the River Murray floodplains has been shown to be in a severe state of decline. This decline is amplified by the impositions of river regulation. In South Australia, where vegetation losses have been great, regeneration is limited and may result in not only individual tree losses but also widespread population decline. This study aimed to examine the relationship between river flows and the regeneration process in populations of Eucalyptus camaldulensis and Eucalyptus largiflorens. The current structure of the populations was examined to determine if a viable number of varying age-classed trees were present. Tree surveys conducted at Banrock Station determined that while densities were low for both species, E. camaldulensis had a more sustainable population structure than E. largiflorens. Growth stages for both species illustrated highly clumped distribution, which is believed to correspond with river flooding magnitudes and frequencies. To address the potential link between tree distribution and flooding within the River Murray, a hydrological analysis was conducted for Banrock Station using river flows at the South Australian border from 1900 to 2003. The amount of time growth stages for each species were inundated was found to be greatly reduced under regulated flows compared to natural flows. This has resulted in shifted localized regeneration patterns corresponding with E. camaldulensis' greater demand for inundation than E. largiflorens. Moderate magnitude flows have been most impacted by regulation, and consequently these are the very flows needed for floodplain tree population maintenance. Flowering and seed fall for E. camaldulensis and E. largiflorens were monitored at Banrock Station for 22 months to identify losses in reproductive potential resulting from tree decline. While seed viability was not affected by vigour, trees with visually reduced vigour were found to produce less fruit and had reduced seed fall, as well as a reduced rate of fruit development. Dendrochronological techniques were applied to floodplain trees. Age and size relationships could be established, implying that such techniques can be applied in South Australia to high quality sites. Growth responses within cohorts were similar and easily matched between individuals illustrating cyclic, but not necessarily seasonal correlations. This work verified the preferential selection of younger trees for dendroecological studies, and identified a relationship between on moderate flows and measurable girth expansion in both floodplain tree species.Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2004.