Vegetation Management

Throughout the Border Rivers -Gwydir catchment, native vegetation is a basic component of healthy ecosystems. The diversity and resilience of our native vegetation enables landscapes to overcome and recover from the natural extremes of climate and from stresses imposed by anthropogenic landscape use. Native plants have adapted to local conditions and usually present a genetic diversity and tolerance to maintain ecosystems and further evolve despite imposed constraints.

Since European settlement 160 years ago, much of the indigenous forest in New Zealand hill country has been cleared for pastoral agriculture, resulting in increased erosion and sedimentation. To prioritise soil conservation work in the Manawatu-Wanganui region, we developed a model of landslide susceptibility. It assigns high susceptibility to steep land not protected by woody vegetation and low susceptibility everywhere else, following the commonly used approach for identifying inappropriate land use. A major storm on 15-16 February 2004 that produced many landslides was used to validate the model. The model predicted hills at risk to landsliding with moderate accuracy: 58% of erosion scars in the February storm occurred on hillsides considered to be susceptible. The model concept of slope thresholds, above which the probability of landsliding is high and below which the probability is low, is not adequate because below 308 the probability of landsliding is approximately linearly related to slope. Thus, reforestation of steep slopes will need to be combined with improved vegetation management for soil conservation on moderate slopes to significantly reduce future landsliding. D

This is the 68th annual report of the British Trust for Ornithology's Ringing Scheme, covering work carried out, and data received, in 2004. During the year, changes in bird survival in relation to winter weather were studied. In almost all cases, there was a greater influence of weather on firstyear than adult survival. A paper providing guidelines to help those setting up demographic monitoring schemes for waders was produced, with ringing as a key component. Concern about a reduction in reporting rates of ringed birds led to a study of the changes. Declines were found across nearly all taxonomic groups and may reflect a combination of changes in reporting behaviour, ringing behaviour or bird behaviour. A study of the timing of muirburning used the ringing dates of pulli in conjunction with nest record data to assess its possible effect on breeding birds. There appears to be little reason for differences in cut-off dates for muirburning in different regions and at different altitudes, but further work is required to quantify more fully the effects on moorland birds. Data gathered as part of the Constant Effort Sites (CES) Scheme showed increases in the numbers of adults of several, mainly migrant, species, possibly as a result of high rainfall in Africa south of the Sahara. Productivity was good for most species. Cetti's Warbler Cettia cetti was added to the list of species covered and a study of habitat on CE sites showed that vegetation management mitigates the effect of habitat progression on catching rates. Data for 117 Retrapping Adults for Survival (RAS) studies were submitted. Over 12,000 Swallows Hirundo rustica were ringed as part of the Swallow Roost Project. The total number of birds ringed (881,920) was the highest ever, showing an 18% increase on the mean of the previous five years (1999)(2000)(2001)(2002)(2003). The recovery total (11,930) also increased (by 9% compared to the mean of the previous five years). Recoveries of 154 BTO-ringed birds and 102 ringed abroad are presented in the report. They include records that confirm suspected or known migration patterns as well as the more unexpected movements.

Although wetland restoration has been a key part of U.S. environmental policy for 20 years (i.e., ''no net loss''), there is little long-term data on restorations to guide planning and assessment. Understanding how restored wetland communities deviate from natural conditions, and how long those deviations persist, can provide important insights into the mechanisms of recovery and improve restoration practice. This study reports the results from a 19-year survey of 37 restored prairie pothole wetlands in northern Iowa, southern Minnesota, and southeastern South Dakota. Complete floristic surveys were performed for each of the wetlands in 1989, 1990, 1991, 2000, and 2007. The accumulation of wetland species across all sites was greatest during the first 12 years after reflooding (14.4 species/year), after which the rate declined to 1.6 species/year. Proximity to natural wetlands and a semi-permanent water regime favored species accumulations during the first 12 years, but changes since then are primarily linked to water regime. Semi-permanent wetlands have experienced fewer major gains and losses in species richness, whereas temporary and seasonal wetlands have been less stable. From 2000 to 2007, extinctions exceeded colonizations in all wetlands, resulting in a convergence of beta diversity. Although 77% of the species considered common to natural wetlands in the region established in these restorations, 70% of those considered infrequent have not. The likelihood that these restorations will eventually support many additional species appears low, given the presence of barriers to recovery, especially the dominance of invasive perennials (e.g., Phalaris arundinacea and Typha angustifolia/x glauca) on all sites and the low colonization efficiency of wet prairie, sedge meadow, and woody perennial species. Management, such as active revegetation of these low efficiency species guilds, particularly sedge meadow and wet prairie perennials, and invasive species control is needed to ensure that restored prairie wetlands support the region's biodiversity. The important barriers to the recovery of prairie pothole restoration: isolation, infrequent flooding, and invasive species, are all factors that do not self-correct over time and need to be addressed during planning by establishing sound practices for initial implementation and longterm vegetation management.

Wet meadows are one of the most vital biotopes of the Prespa Lakes ecosystem. Since the mid 1970's, radical changes in the local primary sector activities led to the abandonment of their traditional management and consequently to the critical decrease of their total surface area at Lake Mikri Prespa, negatively affecting aquatic bird species, which use wet meadows as main feeding grounds. Presently, through the LIFE Nature project titled "Conservation of Priority Bird Species at Lake Mikri Prespa, Greece" vegetation management aims at the restoration of wet meadows, while hydrological management aims at improving water level control. Simultaneously, systematic monitoring of the managed vegetation and the use of the managed areas by bird fauna is carried out in order to follow up the results of the management interventions. The present paper describes the conservation efforts for the restoration of wet meadows applied by the Society for the Protection of Prespa and relevant authorities and institutions and includes proposals for their future management.

Dune slack habitats are highly dependent on the availability of water to support flora and fauna. Typically this is provided by shallow groundwater. This paper describes the seasonal and long term variation in groundwater levels in part of the Sefton coastline between 1972 and 2007. The effects of climate change, vegetation management and coastline realignment on groundwater levels are modelled. The observed annual water table levels rise and fall with an amplitude of 1.5 m, but longer term variations and trends are apparent. A stochastic water balance model was used to describe the changes in water table levels in slack floors in the open dunes and also in areas afforested with pine trees. It was found that the pine trees evaporated 214 mm/year more than open dunes vegetation, resulting in the water table being 0.5-1.0 m lower under the trees than under the open dunes. The effects of climate change on the ground water was simulated using predictions of future climate conditions based on the UKCIP02 medium high emissions scenario. The increase in temperature and change in rainfall patterns will result in a decrease in mean ground water levels by 1.0-1.5 mm in the next 90 years. Typical patterns consist of sequences of 5-10 years of low water table levels interspersed by infrequent sequences consisting of 2-5 years of relatively high or "normal" levels. These results indicate that that flora and fauna that cannot survive a 5-10 year period of water table levels >2.5 m below ground level are unlikely to survive or persist in many slack areas and a change in the ecology of these slack may become inevitable. Other effects of climate change include sea level rise which will result in a gradual rise in water table levels. Coastal erosion will increase the water table gradient to the sea and result in a slight lowering of the ground water levels. Conversely coastal accretion will reverse this process. The spatial distribution of coastal erosion and accretion along the Sefton coastline and its likely impacts on groundwater levels are discussed. The modelling work described in this paper has identified the factors which have the largest effect on groundwater levels in temperate coastal dune systems.

Typically, it has been a challenge for utility companies to implement more automated approaches to powerline maintenance. Our study considers using two emerging technologies - LIDAR and direct multiple viewing digital cameras - to address an aspect of this challenge. Airborne-LIDAR and the direct geo-referenced digital cameras are presented as tools for managing vegetation in a utility's Right-Of-Way: to maintain required clearances between powerlines and surrounding vegetation, and to detect change in the vegetation over a given timeframe. Digitizing LIDAR waveforms for powerline management will have an impact on the way powerline companies operate. We highlight here advantages and drawbacks utility firms may face in leveraging this new technology. This new surveying technique will also be assessed with respect to the risk management cycle and the national regulations to ensure it permits utility companies to fulfil the requirements of policies regarding powerline safety. Draw...

Soil nitrate (NO 3 À ) accumulation rates were assessed among seven weed species grown in small plots during the summer of 1997, at a northern Ontario location. Objectives were (1) to quantify soil nitrate accumulation rates at varying weed densities established on three soil types (clay, loam, and sand) and (2) to assess the effects of soil nitrate levels on weed and black spruce (Picea mariana (Mill.) B.S.P.) seedling growth and weed growth. Controlled densities (0, 0.5, 2, 8 stems per m 2 ) of red raspberry (Rubus idaeus L. var. strigosus (Michx.) Maxim.), ®reweed (Epilobium angustifolium L.), and a grass species (Calamagrostis canadensis (Michx.) Nutt.) were planted along with spruce seedlings (1 m spacing) early in the summer of 1994. Concurrently, four more deciduous weed species, trembling aspen (Populus tremuloides Michx.), white birch (Betula papyrifera Marsh.), green alder (Alnus crispa (Ait.) Pursh), and willow (Salix humilis Marsh.) were also established at four densities (0, 0.5, 2, 4 stems per m 2 ). In mid-summer (July) 1997, soil samples collected from the respective weed densities were placed in polyethylene bags and the bags were incubated in the respective plots for 34 days at a depth of 12 cm. Nitrate accumulation rates (mg per 100 gm of dry soil per day), weed heights, and the effective leaf area index (LAIe, in m 2 m À2 , measured with a Licor LAI-2000 Plant Canopy Analyzer) of competing vegetation were consistently higher (1.4±3.0 times) for clay soil. Nitrate levels were signi®cantly (p < 0.05) higher in clay soils obtained from plots planted with raspberry, grass, aspen, and willow. Carbon : nitrogen (C : N) ratios were higher for loam soils than those for clay or sand soils, and these higher ratios may have resulted in more immobilization than mineralization of soil nitrogen. Nitrate levels for clays and loams correlated signi®cantly with the LAIe of competing vegetation (r 0.62±0.78) and with weed growth (r 0.75±0.96), but non-signi®cantly, and often negatively, with spruce stem volume. To date, soil nitrate accumulation appears to have primarily bene®ted cultivated weeds and not to have improved spruce growth. These ®ndings af®rm that weeds must be controlled for seedlings to bene®t nutritionally. #

Most agroforestry projects and plantations for biomass production may affect soil properties and status. The objective of this work was to know the effects of paulownia (Paulownia ssp.) plantation on the chemical, physical and microbiological properties of soils in Mediterranean agricultural areas. Aleppo pine (Pinus halepensis L.) forestations, maize (Zea mays L.) crops and soils without human interference were also selected in the same area in order to compare results obtained. Paulownia plantations and maize crops showed higher values of organic matter content, total N, total organic carbon and heavy metals (Cu, Cr, Pb, Ni and Zn). However, Aleppo pine forestations and control plots presented higher enzymatic activities (phosphatase, β-glucosidase and dehydrogenase) and soil respiration than agricultural uses or paulownia plantations. Thus, the ploughing operations with the consequent increased soil aeration, fertilization and cropping practices, as well as the vegetation management and composition negatively influence microbial populations and enzyme activity. Paulownia plantation should avoid the use of machinery and fertilization, which incorporate heavy metals into the soil or increases soil aeration, reducing the soil respiration and enzymatic activity levels. Moreover, enzymes and soil respiration might be useful as early indicators of biological changes.► We evaluate the effects of fast-growing paulownia plantations, Aleppo pine forestations, maize crops and soils without human interference on the chemical, physical and microbiological soil properties. ► Aleppo pine forestations and control plots presented higher enzymatic activities and soil respiration than agricultural uses or paulownia plantations. ► Soil aeration or heavy metals found in the Paulownia plantations reduce the soil respiration and enzymatic activity levels. ► Enzymes and soil respiration might be useful as early indicators of biological changes.

This paper presents an agent-based model of a land market, which is used to explore the effects of land taxes on the land use in a coastal zone. The model simulates the emergence of land prices and urban land patterns from bottom-up via interactions of individual agents in a land market. A series of model experiments helps visualize and explore how economic incentives in a land market may influence the spatial distribution of land prices and urban developments, either leaving space for coastal ecosystems or not. We demonstrate that economic incentives do affect urban form and pattern, land prices and welfare measures. However, they may not always be sufficient to reduce the pressure on coastal ecosystems. Our results show that preservation of ecosystems may involve difficult trade-offs between economic and ecological priorities, as well as between healthy ecosystems and social equity. We also show how conventional economic modelling based on a representative agent, which is usually employed by policy makers, overestimates both environmental benefits and economic costs associated with the tax meant to preserve coastal ecosystems. (T. Filatova), [email protected] (A. Voinov), [email protected] (A. van der Veen).

Road construction through sulfidic materials in Virginia has resulted in localized acid rock drainage (ARD) that threatens water quality, fill stability, integrity of building materials, and vegetation management. The objectives of this study were: i) to develop a statewide sulfide hazard rating map based on characterization of the geologic formations associated with acid roadcuts, ii) to estimate depth to sulfidic sediments in the Coastal Plain based on landscape relationships, and iii) to evaluate potential acidity testing procedures on diverse materials. Geologic formations associated with acid roadcuts were characterized by potential peroxide acidity (PPA) and S content, and grouped into four categories. Listed in order of increasing severity, these formations included: the Tabb Formation (Coastal Plain), the Lynchburg Group of the Ashe Formation (Blue Ridge), the Chesapeake Group and Lower Tertiary deposits (Coastal Plain), the Millboro shale, Marcellus shale, Chatanooga shale and Needmore Formation (Valley and Ridge), and the Quantico Formation (Piedmont). Evaluation of landscape parameters near Richmond, Virginia, indicated that the likelihood of encountering sulfidic materials within a given depth at a specific location was related to elevation and mapped soil types. Elevation and soil map units were assigned to risk classes to indicate the likelihood of encountering sulfides within a depth of 9 m. Comparison of PPA and S content for 296 diverse samples indicated that S may serve as a screening tool to evaluate materials without carbonates. Comparison of PPA and conventional Acid-Base Accounting (ABA) for 14 diverse samples indicated that PPA and ABA were highly correlated, with PPA yielding 0.60 to 0.95X the amount of acidity as ABA. Potential acidity by Soxhlet extraction and PPA were equivalent for 3 of 4 diverse samples. Average acidity and metal contents of leachate from Soxhlet extractors were correlated with acidity and metals of road drainage. Sulfide hazard analysis should be an essential step in the pre-design phase of highway construction and other earth-disturbing activities.

Charcoal recovered from different archaeological excavations carried out in the Teotihuacan Valley, Mé xico was used to evaluate whether significant changes in the use of wood took place through time (approx. 400 B.C.-A.D. 1500). Sixteen taxa of trees and shrubs characteristic of the Basin of Mexico were identified (including Pinus, Quercus, Arbutus, Cupressaceae, Alnus, Prunus, Taxodium, Salix, Baccharis and Buddleia, among others). Variations in the proportions of taxa are interpreted as a reflection of the intensity of use rather than an indicator of deforestation. The analysis of the data shows a pattern of continuity in the utilization of taxa throughout the occupation. This includes the use of different vegetative parts (trunk and branches), genera and species with different life forms (trees, shrubs, herbaceous plants) and primary (Pinus and Quercus) as well as secondary taxa (Prunus and Arbutus). We propose that the inhabitants of the Teotihuacan Valley implemented practices to manage vegetation in order to assure resource availability in the region.

Vegetation management, using prescribed fire and herbicides, is used in forestry applications to reduce competition with desired species, improve wildlife habitat, and meet other silvicultural objectives. Although plant communities resulting from such treatments are generally known, it is unclear how pre-treatment plant community structure may influence specific plant community responses. Therefore, to examine how species dominance may impact response of plant communities to vegetation management, we compared the top contributors to plant biomass (kg ha −1 ) among prescribed fire and herbicide (imazapyr) treatments within intensively managed pine stands in east-central Mississippi, USA. Ninetytwo species of 390 collected comprised 95% of plant biomass and six species comprised 55% of total biomass. Dominant species may have restricted plant diversity. Prescribed fire with and without imazapyr improved species richness but did not control some highly competitive species. None of the treatments tested is necessarily an optimal solution to control well-established understory plant species. Although management prescriptions consider exotic and invasive plant species, control of well-established native species should also be considered to tailor vegetation management to meet forestry and wildlife habitat objectives. More research is needed concerning plant response to multiple herbicide tank mixtures with and without prescribed fire to optimize future vegetation management for multiple objectives.

In Japan, forests associated with shrines and temples are recognized as important components of urban green space, which can potentially function as centers for ecosystem conservation in rapidly urbanizing Japanese cities. In addition to their ecological value, shrine/temple forests have social value, providing recreational and aesthetic needs to residents of urban areas. We review the historical development of shrine/temple forests in Japan and discuss current conservation issues from both ecological and sociological perspectives. Generally, shrine forests are minimally managed and public access is discouraged, whereas temple forests are intensively managed for public display. Shrines tend to be spatially scattered across the landscape but associated with specific geographical features, whereas temples tend to be clustered. Their wide and random distribution in urban areas suggests that shrine forests can potentially be used as stepping stones in the urban green space network, whereas spatially clustered temple forests can be integrated to form large areas of green space. Species diversity of shrine/temple forests declines with decreasing area. The distribution pattern of species is not completely nested, indicating that although conservation of large forest fragments may be effective for maintaining landscape-level biodiversity, smaller forest fragments and adjacent precincts are sometimes significant because rare species occasionally inhabit them. Active management and ecological restoration, such as removal of invasive species, are also important to maintain the desirable near-natural forest conditions. A working group including the owner, community, regional government, and ecologists should be involved in creating an effective, longterm management plan. Because social and cultural values are diverse, basic ecological studies of shrine/temple forests would contribute a scientific basis that fosters public confidence in the process.

One of the first considerations in developing a strong and comprehensive urban forestry program is determining the desired outcomes from managing and maintaining vegetation in cities. Urban trees offer a wide range of potential benefits to the urban environment and society. However, there also are a wide range of potential costs and, as with all ecosystems, numerous interactions that must be understood if society is to optimize the net benefits from urban vegetation. Inadequate understanding of the wide range of benefits, costs, and expected outcomes of urban vegetation management designs and plans, as well as interactions among them, may drastically reduce the contribution of vegetation toward improving urban life and the environment. By altering the type and arrangement of trees in a city (i.e., the urban forest structure), one can directly and indirectly affect the city's physical, biological, and socioeconomic environments. Management plans can be developed and implemented to address specific problems within cities. Though trees can provide mUltiple benefits at one site, not all benefits can be realized in each location. Individual management plans should focus on optimizing the mix of benefits that are most important in a particular area. 2. Physical-Biological Benefits and Costs of Urban Vegetation Through proper planning, designing, and management, urban trees can mitigate many of the environmental impacts of urban development by moderating climate, reducing building energy use and atmospheric carbon dioxide (C0 2), improving air quality, lowering rain

Forestry occupations are known to be physically demanding, and workers are often paid on a piece rate basis. This pay system is largely used in silvicultural treatments such as plantation and vegetation management. An ill adjusted piece rate system may induce workforce recruitment difficulties or increase accident rates and work related illnesses. A study combining work measurement, ergonomics and economics was undertaken to better understand the factors influencing a worker's workload. Mathematical relations between site factors, worker's production and heart rate variation during work have been examined based on time and motion studies of 38 brushsaw operators performing regeneration release (cleaning) in northern forests. Results show that a piece rate pay system that considers only the area treated without taking into account site factors may lead workers to behave in ways that may compromise their health and safety. The use of a pay system that integrates the influence of site factors on work performance is therefore suggested.

As Bangladesh is situated in the tropical region, therefore, the growth of vegetation on the archaeological monuments and their surroundings is quite common. Their growth creates a series of threats for monuments including disfiguring the aesthetic beauty, cracking and detachment of masonry and ultimately the collapse of the monuments. This research aims to provide guidelines for the management of vegetation in archaeological sites of Bangladesh. We think every archaeological site should have a vegetation management plan. It should be comprised with regular and seasonal cleaning of the monument and site, remedial and preventive measures against harmful vegetation on the monument, care for the olden and religiously valued trees around the monument, maintenance of the Garden (if any) and vigilance for the plants with the periphery of the monument. Vigilance is the most important aspect that could be greatly reduced the threats caused by plants. For effective vegetation management plan the responsible staffs is needed who are fully aware of the consequences of their delayed actions and the cost involved therein.