Evidence-based conservation seeks to incorporate sound scientific information into environmental decision making. The application of this concept in urban forest management has tremendous potential, but to date has be...Evidence-based conservation seeks to incorporate sound scientific information into environmental decision making. The application of this concept in urban forest management has tremendous potential, but to date has been little applied, largely because existing scientific studies emphasize the importance of urban forests in large-scale ecological and anthropogenic processes, but in practice, scientific evidence is ostensibly incorporated into North American urban forest management only when deciding the fate of individual trees. Even under these disjunctive conditions, the degree to which evidence influences tree-level decisions remains debatable. In analyzing preliminary data from a case study from Toronto, Canada, we sought to test if and how scientific evidence factored into the decision to remove or preserve 53 trees, located in close proximity to a provincially significant area of natural and scientific interest (ANSI). We found that by far the strongest tree-level correlate of the recommendation to remove or preserve trees was whether or not an individual tree was in conflict with proposed development. In comparison, species identity, tree condition, and suitability for conservation were statistically unrelated to the final recommendation. Our findings provide the basis to expand our analysis to multiple case studies across Canada, and internationally. Furthermore, when interpreted with available research and policy, our preliminary (and future) analysis highlights clear opportunities where scientific evidence can and should be readily incorporated into urban forestry management and policy.展开更多
Discounted cash flow analysis is one of the standard methods used to value urban forests and trees. It involves calculating today’s value for all benefits and costs attributed to an investment;that is discounting all...Discounted cash flow analysis is one of the standard methods used to value urban forests and trees. It involves calculating today’s value for all benefits and costs attributed to an investment;that is discounting all cash flows to today’s value using an appropriate interest rate. This requires each benefit and cost be stated in terms of its cash flow. Urban tree benefits are complex. Little notice is given to the components of these benefits. Total urban tree benefits are a summation of partial benefits, including property value increase, storm water reduction, air quality improvement, carbon sequestration, natural gas savings, and electricity savings. We discuss the nature of these partial benefits, especially the geographical, temporal, diameter size, and rate of growth differences. These differences are even reflected in nursery stock valuation. Net present value analysis is used to illustrate the impact of these differences on financial return. An understanding of these components will prove valuable to those attempting to estimate urban forest and tree benefits.展开更多
The relationship between ecosystem services and urban phytodiversity is being studied in the Moukonzi-Ngouaka district of Brazzaville. Urban forestry, a source of well-being for the inhabitants, is associated with soc...The relationship between ecosystem services and urban phytodiversity is being studied in the Moukonzi-Ngouaka district of Brazzaville. Urban forestry, a source of well-being for the inhabitants, is associated with socio-cultural foundations. The surveys concern flora, ethnobotany, socio-economics and personal interviews. The 60.30% naturalized flora is heterogeneous and closely correlated with traditional knowledge. The Guineo-Congolese endemic element groups are 39.27% of the taxa, of which 3.27% are native to Brazzaville. Ethnobotany recognizes 48.36% ornamental taxa;28.36% food taxa;and 35.27% medicinal taxa. Some multiple-use plants are involved in more than one field. The supply service, a food and phytotherapeutic source, provides the vegetative and generative organs. Of the 52.31% of recognized taxa, 33.45% essentially provide leaves and 18.50% fruits. The main obsession of plant introduction being 1) food and phytotherapeutic, and 2) aesthetic, obscures other ecosystem services such as fuelwood and income, provided by NTFPs, pillars of poverty alleviation.展开更多
One of the main issues in tree stability evaluations is the scheduling of adequate monitoring programs. Generally, after a tree analysis, an arborist indicates the required maintenance operations and the timing for pe...One of the main issues in tree stability evaluations is the scheduling of adequate monitoring programs. Generally, after a tree analysis, an arborist indicates the required maintenance operations and the timing for periodical inspection. Field conditions, tree species and biomechanical defects influence the plan. Three old trees （Populus spp. and Celtis australis） located within Golf Club Verona （Sommacampagna, Italy） were monitored periodically from 2010 to present. In addition to visual assessment, authors used sonic tomography to evaluate development of internal defects and planning the maintenance. The aim of this work is to identify a methodology for observing significant difference in tomograms, in order to understand the appropriate interval between instrumental analyses.展开更多
The largest and most important family in Russian conifers is Pinaceae （27-29 species）. The most important problems in the field of systemitics concern some critical taxa. In the result of author＇s research, the new...The largest and most important family in Russian conifers is Pinaceae （27-29 species）. The most important problems in the field of systemitics concern some critical taxa. In the result of author＇s research, the new signs of vegetative and reproductive organs have been checked out and elaborated. It leads to the clarifying of new taxonomic status and geographical distribution of certain critical taxa. A set of species are threatened and need special measures which are included into the Red Data Book of Russian Federation. for their conservation. There are 13 species and one variety展开更多
文摘Evidence-based conservation seeks to incorporate sound scientific information into environmental decision making. The application of this concept in urban forest management has tremendous potential, but to date has been little applied, largely because existing scientific studies emphasize the importance of urban forests in large-scale ecological and anthropogenic processes, but in practice, scientific evidence is ostensibly incorporated into North American urban forest management only when deciding the fate of individual trees. Even under these disjunctive conditions, the degree to which evidence influences tree-level decisions remains debatable. In analyzing preliminary data from a case study from Toronto, Canada, we sought to test if and how scientific evidence factored into the decision to remove or preserve 53 trees, located in close proximity to a provincially significant area of natural and scientific interest (ANSI). We found that by far the strongest tree-level correlate of the recommendation to remove or preserve trees was whether or not an individual tree was in conflict with proposed development. In comparison, species identity, tree condition, and suitability for conservation were statistically unrelated to the final recommendation. Our findings provide the basis to expand our analysis to multiple case studies across Canada, and internationally. Furthermore, when interpreted with available research and policy, our preliminary (and future) analysis highlights clear opportunities where scientific evidence can and should be readily incorporated into urban forestry management and policy.
文摘Discounted cash flow analysis is one of the standard methods used to value urban forests and trees. It involves calculating today’s value for all benefits and costs attributed to an investment;that is discounting all cash flows to today’s value using an appropriate interest rate. This requires each benefit and cost be stated in terms of its cash flow. Urban tree benefits are complex. Little notice is given to the components of these benefits. Total urban tree benefits are a summation of partial benefits, including property value increase, storm water reduction, air quality improvement, carbon sequestration, natural gas savings, and electricity savings. We discuss the nature of these partial benefits, especially the geographical, temporal, diameter size, and rate of growth differences. These differences are even reflected in nursery stock valuation. Net present value analysis is used to illustrate the impact of these differences on financial return. An understanding of these components will prove valuable to those attempting to estimate urban forest and tree benefits.
文摘The relationship between ecosystem services and urban phytodiversity is being studied in the Moukonzi-Ngouaka district of Brazzaville. Urban forestry, a source of well-being for the inhabitants, is associated with socio-cultural foundations. The surveys concern flora, ethnobotany, socio-economics and personal interviews. The 60.30% naturalized flora is heterogeneous and closely correlated with traditional knowledge. The Guineo-Congolese endemic element groups are 39.27% of the taxa, of which 3.27% are native to Brazzaville. Ethnobotany recognizes 48.36% ornamental taxa;28.36% food taxa;and 35.27% medicinal taxa. Some multiple-use plants are involved in more than one field. The supply service, a food and phytotherapeutic source, provides the vegetative and generative organs. Of the 52.31% of recognized taxa, 33.45% essentially provide leaves and 18.50% fruits. The main obsession of plant introduction being 1) food and phytotherapeutic, and 2) aesthetic, obscures other ecosystem services such as fuelwood and income, provided by NTFPs, pillars of poverty alleviation.
文摘One of the main issues in tree stability evaluations is the scheduling of adequate monitoring programs. Generally, after a tree analysis, an arborist indicates the required maintenance operations and the timing for periodical inspection. Field conditions, tree species and biomechanical defects influence the plan. Three old trees （Populus spp. and Celtis australis） located within Golf Club Verona （Sommacampagna, Italy） were monitored periodically from 2010 to present. In addition to visual assessment, authors used sonic tomography to evaluate development of internal defects and planning the maintenance. The aim of this work is to identify a methodology for observing significant difference in tomograms, in order to understand the appropriate interval between instrumental analyses.
文摘The largest and most important family in Russian conifers is Pinaceae （27-29 species）. The most important problems in the field of systemitics concern some critical taxa. In the result of author＇s research, the new signs of vegetative and reproductive organs have been checked out and elaborated. It leads to the clarifying of new taxonomic status and geographical distribution of certain critical taxa. A set of species are threatened and need special measures which are included into the Red Data Book of Russian Federation. for their conservation. There are 13 species and one variety
