Revised; Originally Published: 2006 / 4 pp.

Natural and anthropogenic disturbances have influenced forest stand structure and affected species compositions within forests for millennia. Disturbances such as fire, severe weather events, and forest management practices may result in significantly reduced tree biomass. Thus, these disturbances may lower canopy closure and stem density in support of forest management goals, such as open oak woodland restoration, or promote an increase in species richness within the forest understory. However, these types of disturbance may also produce the unwanted consequence of opening pathways for the invasion of non-native species. Once established, these non-native species may threaten native plant communities and biodiversity. Here, we elucidate how varied natural and anthropogenic disturbances have altered forest stand structure. One consequence of disturbance has been the increase in the presence and cover of non-native species within upland oak forest sites located in the Daniel Boone National Forest, Kentucky. The results of these studies suggest that timely and effective management strategies are needed to minimize non-native species impact on forested habitats following disturbance, and to promote the desired structural shifts that will sustain diverse habitats and support biodiversity.

The aim of this thesis is to evaluate the capability of radio detection and ranging (radar) data collected by the Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture radar (PALSAR), supported by field measurements obtained through ground survey, to predict and map Above Ground Woody Biomass (AGWB) in the tropical savannas of the developing country of Belize, and to understand how the forest structure may influence the backscatter observed. Firstly, an extensive inventory of the woody vegetation of the tropical savannas of Belize was created by measuring the diameter at breast height (dbh), the total height (ht) and the location of 6547 trees in plots covering a total woodland area of 30.8 hectares, located within four protected areas (the Rio Bravo Conservation and Management Area (11×1ha), Deep River (108×0.1ha) and Manatee Forest Reserve (1ha) and the Bladen Nature Reserve (1ha) and also from plots located in unprotected areas (7×1ha). These measurements of forest structure, when combined with information about forest management practices obtained from local organisations revealed that different forms of protection and management may lead to the development of pine woodlands with different structural characteristics in these savannas. Secondly, a case-study was conducted to establish the sensitivity of the ALOS PALSAR backscatter data to AGWB and determine the effect of sample plot size to their relationship. The findings of this case-study show that the L-band backscatter in these low density pine woodlands is a possible predictor of AGWB and confirm that the appropriate sample plot size for predicting AGWB is one hectare; while the sensitivity degrades significantly with decreasing sample plot size. Taken together, the findings described above were combined to assess the capability of ALOS PALSAR backscatter to predict AGWB in these woodlands. A semi-empirical Water Cloud Model (WCM) describing the interaction between the backscatter and vegetation was re-arranged to enable the prediction of AGWB. Non-linear regression analysis revealed that the ALOS PALSAR backscatter predicted AGWB with an R2=0.92; an external validation conducted with additional ground reference data estimated this AGWB prediction to have an RMSE ~13 t/ha. The form of the regression model linking backscatter to AGWB appears to be particularly influenced by sample plots with higher tree numbers and by plots in which the trees were more homogeneous. The presence of many similar sized individuals within some plots is postulated as one explanation for the elevated saturation level for predictions in this study (> 100 t/ha) compared to other models. The model developed here predicts complete saturation in the backscatter - AGWB relationship to occur primarily as a result of increases in the tree number density and often concurrently in basal area, two parameters which are usually strongly correlated with AGWB in these woodlands. Thirdly, the locally validated relationship between ALOS PALSAR backscatter and AGWB is used to map AGWB for the lowland pine savannas of Belize at a spatial resolution of 100m. The mapping estimates that over 90% of these pine woodlands have an AGWB below 60 t/ha, with the average woody biomass estimated at 23.5 t/ha. When these new predictions are mapped and aggregated over the extents of two protected areas (Rio Bravo and Deep River), the totals obtained agree closely (error ≤20%) with previous estimates of AGWB obtained from ground data and previous research. The combined evidence suggests that woodland protection may produce a small, positive effect upon AGWB, with the mean of the AGWB/ha predictions higher in areas that are protected and managed for biodiversity (29.55 ± 0.84 t/ha) than in other areas that are not protected (23.29 ± 0.19 t/ha). When the fine scale local AGWB mapping produced using ALOS PALSAR is compared cell-by-cell with global biomass products at coarser spatial resolutions (500m and 1000m), the AGWB differences observed range from 115-120%. When the coarser AGWB estimates are aggregated over the extents of Deep River and Rio Bravo, the AGWB totals obtained differ significantly (~280 – 300%) from AGWB estimates from ground data and previous research. Overall, these findings suggest that where sufficient ground data exists to build a reliable local relationship to radar backscatter, more detailed biomass mapping can be produced from ALOS and similar satellite sensor data at resolutions of ~100m. This more accurate and spatially detailed information about the distribution of woody biomass within tropical lowland savannas is more appropriate for monitoring local changes in forest cover and for supporting management decisions for forested areas of around ~10,000ha than estimates based upon previously available, but coarser scale, global biomass products.

Clearance of Eucalyptus woodlands has resulted in soil deterioration and lost agricultural production, due to wind erosion, salinity and soil acidity. Despite increasing efforts to reverse these trends through Landcare and other revegetation and agroforestry programs, there is a lack of experimentally-based information about the effects of trees on native pasture performance. The study was carried out in a temperate environment (Southern Tablelands, New South Wales). The altitude at the study sites ranged from 740 to 880m and the aspect at the experimental plots varied from SE to SW. The nearest site was 16 km from Canberra Airport and all sites were situated within similar rainfall isohyets as Canberra Airport. Thus climatic conditions were expected to be similar. Climate records at Canberra Airport indicate that January is the hottest month with mean maximum temperature of 27.7 �C and July is the coldest month with a maximum of 11.1 �C. Rainfall in the area ranges from 37.5 to 66.0 mm monthly average in June and October respectively. The main tree species in the study area were Eucalyptus pauciflora, E. melliodora and E. mannifera. Furthermore, Poa labillardieri, P. sieberiana, Themeda australis, Danthonia penicillata and Microlaena stipoides were the most abundant pasture species on the experimental plots. Species of clover (Trifolium spp.) were also abundant among the herbs. This study used pasture assessment techniques to quantify the effects of remnant patches of Eucalyptus open woodlands on the composition, quality and biomass production of herbaceous understorey vegetation. Microclimate and soil nutrients were also compared under trees and in the open. In addition, consumption by vertebrate grazers under Eucalyptus trees and in the open was compared. Tree density and basal area were compared with herbage standing crop. Remnant patches of Eucalyptus open woodlands modify the microclimate by reducing wind reaching the understorey vegetation. However no significant effects on ambient air temperature and relative humidity were recorded. The effect of trees on soil moisture was contingent to differences between the four sites and soil depth. Despite a 13% higher soil organic matter in the top 15 cm of soil under trees, soil total nitrogen and total phosphorus did not differ from that in the open. Surface soil pH values were lower (by 0.2 units) under the trees. No significant effect of trees on pasture species richness was found. However the classification of quadrats on the basis of species presence showed a distinction between species composition under trees and in the open at one of the four sites. vi The contribution of pasture species to total dry weight on plots under trees and in the open did depend on the particular species involved and was also contingent to differences between sites. However at the sites where Vulpia bromoides and Poa sieberiana were abundant, the two species dominated the biomass under trees. Whereas Microlaena stipoides var. stipoides dominated the biomass under trees at two sites and in the open at only one of the four sites. Pasture total N content differed between sites. Two of the sites had significantly higher (5.9% and 19.7%) N content under trees. On the contrary, pastures at one site contained 18.7% higher N content in the open. The total P content was 18% higher in pastures under trees. Overall, the pasture standing crop under trees was 15% less than in the open during August to May. Vertebrate grazers consumed about the same amount of pasture under the trees and in the open at the four experimental sites.

This thesis utilizes a distributed hydrologic model to predict hydrologic effects of Low Impact Development (LID), and also analyzes runoff from small sub-areas within the watershed. City planners and developers rely on accurate hydrologic models, which enable them to design flood-proof developments and effectively mitigate flooding downstream. Common hydrologic models use a lumped approach, which averages the physical characteristics of basins for model calculations, limiting their ability to estimate runoff within the basin. In contrast, distributed hydrologic models, which divide the watershed into a grid system, can be used to predict runoff at any location within the watershed. The fully distributed hydrologic model, VfloTM, is used to model stormwater runoff in The Woodlands, TX watershed, and to demonstrate the effectiveness of the master planned community. This thesis also suggests that a calibrated VfloTM model can accurately predict stormwater runoff from small sub-areas within a watershed.

South Africa has a fragmented past. Attempts to redress inequalities must acknowledge and understand the context of rural South Africa in terms of natural ecosystems. We are used to be being told that forests are good for us all. Certainly, the range of benefits that can be derived from forests, specifically natural woodlands are legion. The woodlands in South Africa are essential in the lives of many South Africans. It is for this reason that woodland resources are regarded as extremely important, not only for the maintenance of rural livelihoods but also as a potential contributor to the national economy. The woodlands are a diverse resource, extending over a vast area of the country and across several provincial boundaries. This as well as varied tenure systems as well as management objectives which exist, make the woodlands of South Africa a complex, yet essential resource to manage, monitor and sustain on a national level. Policy should therefore be able to ensure some kind of balance so that woodlands can be conserved, developed and sustainably managed in the most suitable ways possible. The findings of previous studies conducted on the woodland biome have highlighted the lack of sufficient knowledge of community perceptions with regards to the policy issues. This has been the catalyst in promoting informed reviews of current policies, in effect, which are affecting woodlands in African communal rural areas in South Africa. This particular study illustrates that there are a range of policies, both national and international, that impact either directly or indirectly on the woodlands in South Africa. The research identifies some of the key limitations in the various existing policies. Furthermore, the key concern raised is that current policies remain fragmented and are not in synergy with each other. Additionally, the ability to translate policy intentions into practice (that is, the implementation of policy directives) remain problematic. The gaps in the policy environment as well as the failure to implement are the key threats to ensuring the effective use of policy in promoting the sustainability of the woodlands in the South Africa context. / Thesis (M.A.)-University of Durban-Westville, 2002.

Ceramic material culture recovered from archaeological sites has more to offer the researcher than placing the site or strata into a cultural historic timeline. By examining the characteristics of ceramics manufactured during the Woodland Period in southern Kentucky, this thesis answers questions related to the behavior of the potters who lived and worked there. Using the theoretical basis of ceramic ecology and technological choice, this thesis examines the choices made by the potters of two sites, the Long (15Ru17) and Rowena (15Ru10) sites, located along the Cumberland River in Russell County, Kentucky. The two sites are also compared to one another and similar assemblages in the Upper Cumberland River Valley, in terms of temporal occupation and utilization of tempering resources. Ultimately, the potters who occupied the Long and Rowena sites during the Woodland Period used locally available materials to temper their clay, even as they emulated other ceramic types. In terms of the two sites themselves, it appears that while they were not occupied by the same population of potters, they did employ similar tempering agents and stylistic types. Examining the behavior of potters who occupied these two sites informs the researcher about the behavior of the larger region of the Upper Cumberland Valley.

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Diss. Uppsala : Sveriges lantbruksuniv., 2003.