SWAT (Student Weekend Arborist Team): A Model for Land Grant Institutions and Cooperative Extension Systems to Conduct Street Tree Inventories

Science.gov (United States)

Cowett, F.D.; Bassuk, N.L.

2012-01-01

SWAT (Student Weekend Arborist Team) is a program affiliated with Cornell University and Extension founded to conduct street tree inventories in New York State communities with 10,000 residents or fewer, a group of communities underserved in community forestry planning. Between 2002 and 2010, SWAT conducted 40 inventories, and data from these…

Aerodynamic effects of trees on pollutant concentration in street canyons.

Science.gov (United States)

Buccolieri, Riccardo; Gromke, Christof; Di Sabatino, Silvana; Ruck, Bodo

2009-09-15

This paper deals with aerodynamic effects of avenue-like tree planting on flow and traffic-originated pollutant dispersion in urban street canyons by means of wind tunnel experiments and numerical simulations. Several parameters affecting pedestrian level concentration are investigated, namely plant morphology, positioning and arrangement. We extend our previous work in this novel aspect of research to new configurations which comprise tree planting of different crown porosity and stand density, planted in two rows within a canyon of street width to building height ratio W/H=2 with perpendicular approaching wind. Sulfur hexafluoride was used as tracer gas to model the traffic emissions. Complementary to wind tunnel experiments, 3D numerical simulations were performed with the Computational Fluid Dynamics (CFD) code FLUENT using a Reynolds Stress turbulence closure for flow and the advection-diffusion method for concentration calculations. In the presence of trees, both measurements and simulations showed considerable larger pollutant concentrations near the leeward wall and slightly lower concentrations near the windward wall in comparison with the tree-less case. Tree stand density and crown porosity were found to be of minor importance in affecting pollutant concentration. On the other hand, the analysis indicated that W/H is a more crucial parameter. The larger the value of W/H the smaller is the effect of trees on pedestrian level concentration regardless of tree morphology and arrangement. A preliminary analysis of approaching flow velocities showed that at low wind speed the effect of trees on concentrations is worst than at higher speed. The investigations carried out in this work allowed us to set up an appropriate CFD modelling methodology for the study of the aerodynamic effects of tree planting in street canyons. The results obtained can be used by city planners for the design of tree planting in the urban environment with regard to air quality issues.

Biodiversity on Broadway--enigmatic diversity of the societies of ants (Formicidae on the streets of New York City.

Directory of Open Access Journals (Sweden)

Marko Pećarević

2010-10-01

Full Text Available Each year, a larger proportion of the Earth's surface is urbanized, and a larger proportion of the people on Earth lives in those urban areas. The everyday nature, however, that humans encounter in cities remains poorly understood. Here, we consider perhaps the most urban green habitat, street medians. We sampled ants from forty-four medians along three boulevards in New York City and examined how median properties affect the abundance and species richness of native and introduced ants found on them. Ant species richness varied among streets and increased with area but was independent of the other median attributes measured. Ant assemblages were highly nested, with three numerically dominant species present at all medians and additional species present at a subset of medians. The most common ant species were the introduced Pavement ant (Tetramorium caespitum and the native Thief ant (Solenopsis molesta and Cornfield ant (Lasius neoniger. The common introduced species on the medians responded differently to natural and disturbed elements of medians. Tetramorium caespitum was most abundant in small medians, with the greatest edge/area ratio, particularly if those medians had few trees, whereas Nylanderia flavipes was most abundant in the largest medians, particularly if they had more trees. Many of the species encountered in Manhattan were similar to those found in other large North American cities, such that a relatively small subset of ant species probably represent most of the encounters humans have with ants in North America.

High-resolution tree canopy mapping for New York City using LIDAR and object-based image analysis

Science.gov (United States)

MacFaden, Sean W.; O'Neil-Dunne, Jarlath P. M.; Royar, Anna R.; Lu, Jacqueline W. T.; Rundle, Andrew G.

2012-01-01

Urban tree canopy is widely believed to have myriad environmental, social, and human-health benefits, but a lack of precise canopy estimates has hindered quantification of these benefits in many municipalities. This problem was addressed for New York City using object-based image analysis (OBIA) to develop a comprehensive land-cover map, including tree canopy to the scale of individual trees. Mapping was performed using a rule-based expert system that relied primarily on high-resolution LIDAR, specifically its capacity for evaluating the height and texture of aboveground features. Multispectral imagery was also used, but shadowing and varying temporal conditions limited its utility. Contextual analysis was a key part of classification, distinguishing trees according to their physical and spectral properties as well as their relationships to adjacent, nonvegetated features. The automated product was extensively reviewed and edited via manual interpretation, and overall per-pixel accuracy of the final map was 96%. Although manual editing had only a marginal effect on accuracy despite requiring a majority of project effort, it maximized aesthetic quality and ensured the capture of small, isolated trees. Converting high-resolution LIDAR and imagery into usable information is a nontrivial exercise, requiring significant processing time and labor, but an expert system-based combination of OBIA and manual review was an effective method for fine-scale canopy mapping in a complex urban environment.

WIND DAMAGE ON TREES FOLLOWING HURRICANE SANDY AND IMPLICATIONS FOR CITY LANDSCAPING: GLEN RIDGE – MONTCLAIR TOWNS, NEW JERSEY

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FAITH JUSTUS

2013-05-01

Full Text Available Glen Ridge is a small municipality in the Northern New Jersey with a significant number of huge trees lining majority of its streets. The trees have been subject to a wide range of natural and artificial stresses, one being the strong wind associated with superstorm Sandy. On 29th October 2012, a windstorm of extreme intensity struck the Tristate region and brought havoc to the tree population including those in Glen Ridge. A survey was conducted immediately after the storm to collect quantitative information on fallen tree population. The study aimed at understanding the spatial extent of wind damage on trees with reference to location, trunk diameter and soil characteristics. A total of 51 fallen trees with a mean trunk diameter of 100.4 centimetres along streets in study area were surveyed. High damage was noted on trees in Glen Ridge (29 trees while streets transitioning to Montclair had 22 fallen trees. Majority of the surveyed trees were found on USBOO soils (49%, which are characterised as disturbed urban soils with Boonton substratum-Boonton complexes. BowrB soils had 27.5%, Boob 13.7%, BowrC 7.8% and USDUNB 2.0% of fallen trees. A need for city wide tree inventorying and species mapping is identified as a management implication to further enhance the historical value of the city. Other measures are discussed with a view of engaging appropriate local management partnerships and coordination frameworks to play a role in protecting the remaining large trees.

The marginal cost of carbon abatement from planting street trees in New York City

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Kent F. Kovacs; Robert G. Haight; Suhyun Jung; Dexter H. Locke; Jarlath. O' Neil-Dunne

2013-01-01

Urban trees can store carbon through the growth process and reduce fossil fuel use by lowering cooling and heating energy consumption of buildings through the process of transpiration, shading, and the blocking of wind. However, the planting and maintenance of urban trees come at a cost. We estimate the discounted cost of net carbon reductions associated with planting...

Evaluation of impacts of trees on PM2.5 dispersion in urban streets

Science.gov (United States)

Jin, Sijia; Guo, Jiankang; Wheeler, Stephen; Kan, Liyan; Che, Shengquan

2014-12-01

Reducing airborne particulate matter (PM), especially PM2.5 (PM with aerodynamic diameters of 2.5 μm or less), in urban street canyons is critical to the health of central city population. Tree-planting in urban street canyons is a double-edged sword, providing landscape benefits while inevitably resulting in PM2.5 concentrating at street level, thus showing negative environmental effects. Thereby, it is necessary to quantify the impact of trees on PM2.5 dispersion and obtain the optimum structure of street trees for minimizing the PM2.5 concentration in street canyons. However, most of the previous findings in this field were derived from wind tunnel or numerical simulation rather than on-site measuring data. In this study, a seasonal investigation was performed in six typical street canyons in the residential area of central Shanghai, which has been suffering from haze pollution while having large numbers of green streets. We monitored and measured PM2.5 concentrations at five heights, structural parameters of street trees and weather. For tree-free street canyons, declining PM2.5 concentrations were found with increasing height. However, in presence of trees the reduction rate of PM2.5 concentrations was less pronounced, and for some cases, the concentrations even increased at the top of street canyons, indicating tree canopies are trapping PM2.5. To quantify the decrease of PM2.5 reduction rate, we developed the attenuation coefficient of PM2.5 (PMAC). The wind speed was significantly lower in street canyons with trees than in tree-free ones. A mixed-effects model indicated that canopy density (CD), leaf area index (LAI), rate of change of wind speed were the most significant predictors influencing PMAC. Further regression analysis showed that in order to balance both environmental and landscape benefits of green streets, the optimum range of CD and LAI was 50%-60% and 1.5-2.0 respectively. We concluded by suggesting an optimized tree-planting pattern and

Predictive equations for dimensions and leaf area of coastal Southern California street trees

Science.gov (United States)

P.J. Peper; E.G. McPherson; S.M. Mori

2001-01-01

Tree height, crown height, crown width, diameter at breast height (dbh), and leaf area were measured for 16 species of commonly planted street trees in the coastal southern California city of Santa Monica, USA. The randomly sampled trees were planted from 1 to 44 years ago. Using number of years after planting or dbh as explanatory variables, mean values of dbh, tree...

Urban forest management in New England: Towards a contemporary understanding of tree wardens in Massachusetts communities

Science.gov (United States)

Harper, Richard W.; Bloniarz, David V.; DeStefano, Stephen; Nicolson, Craig

2017-01-01

In the New England states, tree wardens are local officials responsible for the preservation, maintenance and stewardship of municipal public trees. This study explores the emerging professional challenges, duties and responsibilities of tree wardens, from the subject’s point of view, by conducting in-person, semi-structured qualitative research interviews with 50 tree wardens throughout Massachusetts. Many of the findings corroborate previous literature, including that tree wardens are typically housed in a municipal department (often public works or highway), that tree wardens routinely interact with a wide variety of local organisations (representatives from other municipal departments, community volunteer associations) and that as community size increases, tree wardens typically have access to a greater pool of resources to carry out urban forest management. A newer finding is that the subject of urban forest health arose as a topic of great importance for tree wardens, as nearly all interviewees (n = 49) indicated that they monitor for urban forest pests and that they would like further continuing education concerning this subject.

A synthesis of radial growth patterns preceding tree mortality

Science.gov (United States)

Cailleret, Maxime; Jansen, Steven; Robert, Elisabeth M.R.; Desoto, Lucia; Aakala, Tuomas; Antos, Joseph A.; Beikircher, Barbara; Bigler, Christof; Bugmann, Harald; Caccianiga, Marco; Cada, Vojtech; Camarero, Jesus J.; Cherubini, Paolo; Cochard, Herve; Coyea, Marie R.; Cufar, Katarina; Das, Adrian J.; Davi, Hendrik; Delzon, Sylvain; Dorman, Michael; Gea-Izquierdo, Guillermo; Gillner, Sten; Haavik, Laurel J.; Hartmann, Henrik; Heres, Ana-Maria; Hultine, Kevin R.; Janda, Pavel; Kane, Jeffrey M.; Kharuk, Vyacheslav I.; Kitzberger, Thomas; Klein, Tamir; Kramer, Koen; Lens, Frederic; Levanic, Tom; Calderon, Juan C. Linares; Lloret, Francisco; Lobo-Do-Vale, Raquel; Lombardi, Fabio; Lopez Rodriguez, Rosana; Makinen, Harri; Mayr, Stefan; Meszaros, IIona; Metsaranta, Juha M.; Minunno, Francesco; Oberhuber, Walter; Papadopoulos, Andreas; Peltoniemi, Mikko; Petritan, Any M.; Rohner, Brigitte; Sanguesa-Barreda, Gabriel; Sarris, Dimitrios; Smith, Jeremy M.; Stan, Amanda B.; Sterck, Frank; Stojanovic, Dejan B.; Suarez, Maria L.; Svoboda, Miroslav; Tognetti, Roberto; Torres-Ruiz, Jose M.; Trotsiuk, Volodymyr; Villalba, Ricardo; Vodde, Floor; Westwood, Alana R.; Wyckoff, Peter H.; Zafirov, Nikolay; Martinez-Vilalta, Jordi

2017-01-01

Tree mortality is a key factor influencing forest functions and dynamics, but our understanding of the mechanisms leading to mortality and the associated changes in tree growth rates are still limited. We compiled a new pan-continental tree-ring width database from sites where both dead and living trees were sampled (2970 dead and 4224 living trees from 190 sites, including 36 species), and compared early and recent growth rates between trees that died and those that survived a given mortality event. We observed a decrease in radial growth before death in ca. 84% of the mortality events. The extent and duration of these reductions were highly variable (1–100 years in 96% of events) due to the complex interactions among study species and the source(s) of mortality. Strong and long-lasting declines were found for gymnosperms, shade- and drought-tolerant species, and trees that died from competition. Angiosperms and trees that died due to biotic attacks (especially bark-beetles) typically showed relatively small and short-term growth reductions. Our analysis did not highlight any universal trade-off between early growth and tree longevity within a species, although this result may also reflect high variability in sampling design among sites. The intersite and interspecific variability in growth patterns before mortality provides valuable information on the nature of the mortality process, which is consistent with our understanding of the physiological mechanisms leading to mortality. Abrupt changes in growth immediately before death can be associated with generalized hydraulic failure and/or bark-beetle attack, while long-term decrease in growth may be associated with a gradual decline in hydraulic performance coupled with depletion in carbon reserves. Our results imply that growth-based mortality algorithms may be a powerful tool for predicting gymnosperm mortality induced by chronic stress, but not necessarily so for angiosperms and in case of intense drought or

Networked governance and the management of ecosystem services: The case of urban environmental stewardship in New York City

Science.gov (United States)

James J.T. Connolly; Erika S. Svendsen; Dana R. Fisher; Lindsay K. Campbell

2014-01-01

Urban environmental stewardship groups have become an essential component of the governance structure that regulates ecosystem services in cities. New York City is one example where these groups have grown rapidly in number, size, and visibility since the 1970s. In this article, we combine quantitative survey data with qualitative interview data to examine the...

How to select the best tree planting locations to enhance air pollution removal in the MillionTreesNYC initiative

International Nuclear Information System (INIS)

Morani, Arianna; Nowak, David J.; Hirabayashi, Satoshi; Calfapietra, Carlo

2011-01-01

Highest priority zones for tree planting within New York City were selected by using a planting priority index developed combining three main indicators: pollution concentration, population density and low canopy cover. This new tree population was projected through time to estimate potential air quality and carbon benefits. Those trees will likely remove more than 10 000 tons of air pollutants and a maximum of 1500 tons of carbon over the next 100 years given a 4% annual mortality rate. Cumulative carbon storage will be reduced through time as carbon loss through tree mortality outweighs carbon accumulation through tree growth. Model projections are strongly affected by mortality rate whose uncertainties limit estimations accuracy. Increasing mortality rate from 4 to 8% per year produce a significant decrease in the total pollution removal over a 100 year period from 11 000 tons to 3000 tons. - Highlights: → The manuscript is part of the IUFRO Special section 'Adaptation of Forest Ecosystems to Air Pollution and Climate Change' (Elena Paoletti and Yusuf Serengil Eds.) approved by William J. Manning. → It has been already peer-reviewed and accepted outside EES. → The reference number of this manuscript is IUFRO49. - Carbon and air pollutant uptake by urban forests are highly influenced by mortality rates.

How to select the best tree planting locations to enhance air pollution removal in the MillionTreesNYC initiative

Energy Technology Data Exchange (ETDEWEB)

Morani, Arianna [Institute of Agro-Environmental and Forest Biology (IBAF), National Research Council (CNR) Via Salaria km 29300, 00015 Monterotondo Scalo, Roma (Italy); Nowak, David J.; Hirabayashi, Satoshi [USDA Forest Service, Northern Research Station, 5 Moon Library, SUNY-ESF, Syracuse, NY 13210 (United States); Calfapietra, Carlo, E-mail: carlo.calfapietra@ibaf.cnr.it [Institute of Agro-Environmental and Forest Biology (IBAF), National Research Council (CNR) Via Salaria km 29300, 00015 Monterotondo Scalo, Roma (Italy)

2011-05-15

Highest priority zones for tree planting within New York City were selected by using a planting priority index developed combining three main indicators: pollution concentration, population density and low canopy cover. This new tree population was projected through time to estimate potential air quality and carbon benefits. Those trees will likely remove more than 10 000 tons of air pollutants and a maximum of 1500 tons of carbon over the next 100 years given a 4% annual mortality rate. Cumulative carbon storage will be reduced through time as carbon loss through tree mortality outweighs carbon accumulation through tree growth. Model projections are strongly affected by mortality rate whose uncertainties limit estimations accuracy. Increasing mortality rate from 4 to 8% per year produce a significant decrease in the total pollution removal over a 100 year period from 11 000 tons to 3000 tons. - Highlights: > The manuscript is part of the IUFRO Special section 'Adaptation of Forest Ecosystems to Air Pollution and Climate Change' (Elena Paoletti and Yusuf Serengil Eds.) approved by William J. Manning. > It has been already peer-reviewed and accepted outside EES. > The reference number of this manuscript is IUFRO49. - Carbon and air pollutant uptake by urban forests are highly influenced by mortality rates.

Million TreesNYC: the integration of research and practice

Science.gov (United States)

Lindsay K. Campbell; Morgan Monaco; Nancy Falxa-Raymond; Jacqueline Lu; Andrew Newman; Ruth A. Rae; Erika S. Svendsen

2014-01-01

MillionTreesNYC is an ambitious campaign to plant and care for one million new trees in New York City. Implemented by the City of New York Department of Parks & Recreation and the nonprofit New York Restoration Project, this innovative, citywide effort crosses property jurisdictions and physical sites. The goal is to enhance the entire 'green matrix' of...

Why do trees die? Characterizing the drivers of background tree mortality

Science.gov (United States)

Das, Adrian J.; Stephenson, Nathan L.; Davis, Kristin P.

2016-01-01

The drivers of background tree mortality rates—the typical low rates of tree mortality found in forests in the absence of acute stresses like drought—are central to our understanding of forest dynamics, the effects of ongoing environmental changes on forests, and the causes and consequences of geographical gradients in the nature and strength of biotic interactions. To shed light on factors contributing to background tree mortality, we analyzed detailed pathological data from 200,668 tree-years of observation and 3,729 individual tree deaths, recorded over a 13-yr period in a network of old-growth forest plots in California's Sierra Nevada mountain range. We found that: (1) Biotic mortality factors (mostly insects and pathogens) dominated (58%), particularly in larger trees (86%). Bark beetles were the most prevalent (40%), even though there were no outbreaks during the study period; in contrast, the contribution of defoliators was negligible. (2) Relative occurrences of broad classes of mortality factors (biotic, 58%; suppression, 51%; and mechanical, 25%) are similar among tree taxa, but may vary with tree size and growth rate. (3) We found little evidence of distinct groups of mortality factors that predictably occur together on trees. Our results have at least three sets of implications. First, rather than being driven by abiotic factors such as lightning or windstorms, the “ambient” or “random” background mortality that many forest models presume to be independent of tree growth rate is instead dominated by biotic agents of tree mortality, with potentially critical implications for forecasting future mortality. Mechanistic models of background mortality, even for healthy, rapidly growing trees, must therefore include the insects and pathogens that kill trees. Second, the biotic agents of tree mortality, instead of occurring in a few predictable combinations, may generally act opportunistically and with a relatively large degree of independence from

Black/white differences in very low birth weight neonatal mortality rates among New York City hospitals.

Science.gov (United States)

Howell, Elizabeth A; Hebert, Paul; Chatterjee, Samprit; Kleinman, Lawrence C; Chassin, Mark R

2008-03-01

We sought to determine whether differences in the hospitals at which black and white infants are born contribute to black/white disparities in very low birth weight neonatal mortality rates in New York City. We performed a population-based cohort study using New York City vital statistics records on all live births and deaths of infants weighing 500 to 1499 g who were born in 45 hospitals between January 1, 1996, and December 31, 2001 (N = 11 781). We measured very low birth weight risk-adjusted neonatal mortality rates for each New York City hospital and assessed differences in the distributions of non-Hispanic black and non-Hispanic white very low birth weight births among these hospitals. Risk-adjusted neonatal mortality rates for very low birth weight infants in New York City hospitals ranged from 9.6 to 27.2 deaths per 1000 births. White very low birth weight infants were more likely to be born in the lowest mortality tertile of hospitals (49%), compared with black very low birth weight infants (29%). We estimated that, if black women delivered in the same hospitals as white women, then black very low birth weight mortality rates would be reduced by 6.7 deaths per 1000 very low birth weight births, removing 34.5% of the black/white disparity in very low birth weight neonatal mortality rates in New York City. Volume of very low birth weight deliveries was modestly associated with very low birth weight mortality rates but explained little of the racial disparity. Black very low birth weight infants more likely to be born in New York City hospitals with higher risk-adjusted neonatal mortality rates than were very low birth weight infants, contributing substantially to black-white disparities.

Effects of Acidic Deposition and Soil Acidification on Sugar Maple Trees in the Adirondack Mountains, New York

Science.gov (United States)

T. J. Sullivan; G. B. Lawrence; S. W. Bailey; T. C. McDonnell; C. M. Beier; K. C. Weathers; G. T. McPherson; D. A. Bishop

2013-01-01

We documented the effects of acidic atmospheric deposition and soil acidification on the canopy health, basal area increment, and regeneration of sugar maple (SM) trees across the Adirondack region of New York State, in the northeastern United States, where SM are plentiful but not well studied and where widespread depletion of soil calcium (Ca) has been...

MillionTreesNYC, Green infrastructure, and urban ecology: building a research agenda

Science.gov (United States)

Jacqueline W.T. Lu; Megan Shane; Erika Svendsen; Lindsay Campbell; Cristiana Fragola; Marianne Krasny; Gina Lovasl; David Maddox; Simon McDonnell; P. Timon McPhearson; Franco Montalto; Andrew Newman; Ellen Pehek; Ruth A. Rae; Richard Stedman; Keith G. Tidball; Lynne Westphal; Tom Whitlow

2009-01-01

MillionTreesNYC is a citywide, public-private initiative with an ambitious goal: to plant and care for one million new trees across New York City's five boroughs by 2017. The Spring 2009 workshop MillionTreesNYC, Green Infrastructure, and Urban Ecology: Building a Research Agenda brought together more than 100 researchers, practitioners and New York City...

City of Pittsburgh Trees

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Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Trees cared for and managed by the City of Pittsburgh Department of Public Works Forestry Division. Tree Benefits are calculated using the National Tree Benefit...

Partial diagnosis of street tree under power lines in West Regional of Minas Gerais

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Altamir Fernandes de Oliveira

2016-03-01

Full Text Available This work aimed to present a partial diagnosis of street tree under power grid in five cities in the West Region of Minas Gerais, which had more power outages because of conflicts with trees. We identified 186 trees, belonging to 17 species of exotic origin and 30 species of native origin. The most frequent species were Poincianella pluviosa (30.43%, Ligustrum lucidum (10.86%, Michelia champaca (6.52% and Schinus molle (4.89%, which together amounted to 52.7% of the assessed trees. Most trees (84.78% were located in streets wider than 7 m, and 36.55% of the trees were planted in sidewalks with a minimum of 2 m wide. Those trees present ther first bifurcation at over 1.80 m above ground level. The pruning performed due to conflicts with the grid amounted 40.22%. Trees with height equal or over 6 m represents 72.83% of the sampled population. It was observed that there is not an appropriate management plan of urban trees under the grid, as the trees frequency is concentrate on few species that were mostly medium and large size.

i-Tree: Tools to assess and manage structure, function, and value of community forests

Science.gov (United States)

Hirabayashi, S.; Nowak, D.; Endreny, T. A.; Kroll, C.; Maco, S.

2011-12-01

grows internationally, environmental databases from more countries will be coupled with the software suite. Two more i-Tree applications, i-Tree Forecast and i-Tree Landscape are now under development. i-Tree Forecast simulates canopy structures for up to 100 years based on planting and mortality rates and adds capabilities for other i-Tree applications to estimate the benefits of future canopy scenarios. While most i-Tree applications employ a spatially lumped approach, i-Tree landscape employs a spatially distributed approach that allows users to map changes in canopy cover and ecosystem services through time and space. These new i-Tree tools provide an advanced platform for urban managers to assess the impact of current and future urban forests. i-Tree allows managers to promote effective urban forest management and sound arboricultural practices by providing information for advocacy and planning, baseline data for making informed decisions, and standardization for comparisons with other communities.

THE ALIEN STREET TREES OF FORTALEZA (NE BRAZIL: QUALITATIVE OBSERVATIONS AND THE INVENTORY OF TWO DISTRICTS

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Marcelo Freire Moro

2011-01-01

Full Text Available Public tree planting is important for cities. It produces shadow, brings well-being for humans, and supports the urban fauna. But the cultivation of exotic plants can also be responsible for dissemination of invasive species. This paper aims to evaluate public tree planting in Fortaleza, Ceará state, in northeastern Brazil. From 2005 to 2009, qualitative observations on tree composition in the city were made. In 2006, a detailed inventory of all public trees was carried out in two districts of Fortaleza. Jointly, 2075 individuals grew here. Most of the tree species planted in Fortaleza are aliens, some are even invasive. The massive use of exotic plants in Fortaleza has negative consequences for the environmental education. People do not know the regional native trees, and thus are not concerned about the local biodiversity conservation. In spite of the huge amounts of native species available for ornamental purposes in the Brazilian flora, the street trees of Fortaleza are overwhelmingly aliens.

Benefits and costs of street trees in Lisbon

Science.gov (United States)

A.L. Soares; F.C. Rego; E.G. McPherson; J.R. Simpson; P.J. Peper; Q. Xiao

2011-01-01

It is well known that urban trees produce various types of benefits and costs. The computer tool i-Tree STRATUM helps quantify tree structure and function, as well as the value of some of these tree services in different municipalities. This study describes one of the first applications of STRATUM outside the U.S. Lisbon’s street trees are dominated by Celtis australis...

The effects of urban warming on herbivore abundance and street tree condition.

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Adam G Dale

Full Text Available Trees are essential to urban habitats because they provide services that benefit the environment and improve human health. Unfortunately, urban trees often have more herbivorous insect pests than rural trees but the mechanisms and consequences of these infestations are not well documented. Here, we examine how temperature affects the abundance of a scale insect, Melanaspis tenebricosa (Comstock (Hemiptera: Diaspididae, on one of the most commonly planted street trees in the eastern U.S. Next, we examine how both pest abundance and temperature are associated with water stress, growth, and condition of 26 urban street trees. Although trees in the warmest urban sites grew the most, they were more water stressed and in worse condition than trees in cooler sites. Our analyses indicate that visible declines in tree condition were best explained by scale-insect infestation rather than temperature. To test the broader relevance of these results, we extend our analysis to a database of more than 2700 Raleigh, US street trees. Plotting these trees on a Landsat thermal image of Raleigh, we found that warmer sites had over 70% more trees in poor condition than those in cooler sites. Our results support previous studies linking warmer urban habitats to greater pest abundance and extend this association to show its effect on street tree condition. Our results suggest that street tree condition and ecosystem services may decline as urban expansion and global warming exacerbate the urban heat island effect. Although our non-probability sampling method limits our scope of inference, our results present a gloomy outlook for urban forests and emphasize the need for management tools. Existing urban tree inventories and thermal maps could be used to identify species that would be most suitable for urban conditions.

Digging the New York City Skyline: soil fungal communities in green roofs and city parks.

Science.gov (United States)

McGuire, Krista L; Payne, Sara G; Palmer, Matthew I; Gillikin, Caitlyn M; Keefe, Dominique; Kim, Su Jin; Gedallovich, Seren M; Discenza, Julia; Rangamannar, Ramya; Koshner, Jennifer A; Massmann, Audrey L; Orazi, Giulia; Essene, Adam; Leff, Jonathan W; Fierer, Noah

2013-01-01

In urban environments, green roofs provide a number of benefits, including decreased urban heat island effects and reduced energy costs for buildings. However, little research has been done on the non-plant biota associated with green roofs, which likely affect their functionality. For the current study, we evaluated whether or not green roofs planted with two native plant communities in New York City functioned as habitats for soil fungal communities, and compared fungal communities in green roof growing media to soil microbial composition in five city parks, including Central Park and the High Line. Ten replicate roofs were sampled one year after planting; three of these roofs were more intensively sampled and compared to nearby city parks. Using Illumina sequencing of the fungal ITS region we found that green roofs supported a diverse fungal community, with numerous taxa belonging to fungal groups capable of surviving in disturbed and polluted habitats. Across roofs, there was significant biogeographical clustering of fungal communities, indicating that community assembly of roof microbes across the greater New York City area is locally variable. Green roof fungal communities were compositionally distinct from city parks and only 54% of the green roof taxa were also found in the park soils. Phospholipid fatty acid analysis revealed that park soils had greater microbial biomass and higher bacterial to fungal ratios than green roof substrates. City park soils were also more enriched with heavy metals, had lower pH, and lower quantities of total bases (Ca, K, and Mg) compared to green roof substrates. While fungal communities were compositionally distinct across green roofs, they did not differentiate by plant community. Together, these results suggest that fungi living in the growing medium of green roofs may be an underestimated component of these biotic systems functioning to support some of the valued ecological services of green roofs.

Digging the New York City Skyline: soil fungal communities in green roofs and city parks.

Directory of Open Access Journals (Sweden)

Krista L McGuire

Full Text Available In urban environments, green roofs provide a number of benefits, including decreased urban heat island effects and reduced energy costs for buildings. However, little research has been done on the non-plant biota associated with green roofs, which likely affect their functionality. For the current study, we evaluated whether or not green roofs planted with two native plant communities in New York City functioned as habitats for soil fungal communities, and compared fungal communities in green roof growing media to soil microbial composition in five city parks, including Central Park and the High Line. Ten replicate roofs were sampled one year after planting; three of these roofs were more intensively sampled and compared to nearby city parks. Using Illumina sequencing of the fungal ITS region we found that green roofs supported a diverse fungal community, with numerous taxa belonging to fungal groups capable of surviving in disturbed and polluted habitats. Across roofs, there was significant biogeographical clustering of fungal communities, indicating that community assembly of roof microbes across the greater New York City area is locally variable. Green roof fungal communities were compositionally distinct from city parks and only 54% of the green roof taxa were also found in the park soils. Phospholipid fatty acid analysis revealed that park soils had greater microbial biomass and higher bacterial to fungal ratios than green roof substrates. City park soils were also more enriched with heavy metals, had lower pH, and lower quantities of total bases (Ca, K, and Mg compared to green roof substrates. While fungal communities were compositionally distinct across green roofs, they did not differentiate by plant community. Together, these results suggest that fungi living in the growing medium of green roofs may be an underestimated component of these biotic systems functioning to support some of the valued ecological services of green roofs.

Tree Mortality

Science.gov (United States)

Mark J. Ambrose

2012-01-01

Tree mortality is a natural process in all forest ecosystems. However, extremely high mortality also can be an indicator of forest health issues. On a regional scale, high mortality levels may indicate widespread insect or disease problems. High mortality may also occur if a large proportion of the forest in a particular region is made up of older, senescent stands....

Managing Tree Diversity: A Comparison of Suburban Development in Two Canadian Cities

Directory of Open Access Journals (Sweden)

Sophie A. Nitoslawski

2016-05-01

Full Text Available Is (suburban forest diversity shaped by previous land use? This study was designed to quantitatively assess the impacts of subdivision development on urban tree-species composition in two Canadian cities: Halifax, Nova Scotia, and London, Ontario. The main goal was to determine whether cities with contrasting pre-urbanized or pre-settlement landscapes—woodlands in Halifax and agricultural fields in London—also revealed differences in urban tree diversity losses and/or gains due to urbanization. In each city, four residential neighbourhoods representing two age categories, older and newer (40–50 years, <15 years, were examined and trees on three land types were sampled: public (street, private (residential, and remnant (woodland. All public street trees within the chosen neighbourhoods were inventoried and approximately 10% of the residential property lots were sampled randomly. Plots were examined in remnant forests in or near each city, representing the original forest habitats prior to agricultural and/or urban landscape transformations. Diameter at breast height, species richness and evenness, and proportions of native and non-native trees were measured. In both cities, streetscapes in newer neighbourhoods exhibit greater species richness and evenness, and are characterized by substantially more native trees. Despite this trend, developers and home owners continue to intensively plant non-native species on newer and smaller property lots. Older neighbourhoods in Halifax containing remnant forest stands hold the greatest number of native trees on private property, alluding to the importance of residual forest buffers and patches in promoting naturalness in the private urban forest. These results suggest that identifying and quantifying flows of species between green spaces during and after development is valuable in order to effectively promote native species establishment and enhance overall urban forest diversity.

Tree Size Comparison of Some Important Street Trees Growing at ...

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PROF HORSFALL

More research is needed on these trees for healthy environment of city. The present ..... use and CO2 emissions from power plants. Environ. Poll. .... Anna. Bot., 65:567-574. Kozlowski, T.T., 1971. Growth and Development of. Trees. Vol. 1.

Integrating human and natural systems in community psychology: an ecological model of stewardship behavior.

Science.gov (United States)

Moskell, Christine; Allred, Shorna Broussard

2013-03-01

Community psychology (CP) research on the natural environment lacks a theoretical framework for analyzing the complex relationship between human systems and the natural world. We introduce other academic fields concerned with the interactions between humans and the natural environment, including environmental sociology and coupled human and natural systems. To demonstrate how the natural environment can be included within CP's ecological framework, we propose an ecological model of urban forest stewardship action. Although ecological models of behavior in CP have previously modeled health behaviors, we argue that these frameworks are also applicable to actions that positively influence the natural environment. We chose the environmental action of urban forest stewardship because cities across the United States are planting millions of trees and increased citizen participation in urban tree planting and stewardship will be needed to sustain the benefits provided by urban trees. We used the framework of an ecological model of behavior to illustrate multiple levels of factors that may promote or hinder involvement in urban forest stewardship actions. The implications of our model for the development of multi-level ecological interventions to foster stewardship actions are discussed, as well as directions for future research to further test and refine the model.

Assessing the Effects of the Urban Forest Restoration Effort of MillionTreesNYC on the Structure and Functioning of New York City Ecosystems

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P. Timon McPhearson

2010-01-01

Full Text Available Current forest restoration practices for New York City’s (NYC MillionTreesNYC Initiative on public parkland include site preparation with extensive invasive species removal and tree and shrub planting with the goal of creating new multi-layered forests. We have launched a long-term investigation of these sites in order to understand the primary physical, chemical, and biological responses of urban ecosystems to MillionTreesNYC forest restoration practices. This research will examine high and low diversity tree and understory planting combinations in permanent experimental forest restoration plots across NYC. The study assesses how the interactions between soil heterogeneity, plant population dynamics, and forest restoration management strategies drive urban forest ecosystem structure and functioning. Working in collaboration with the NYC Department of Parks & Recreation (NYC Parks and the MillionTreesNYC tree planting campaign, we are examining different restoration strategies to assess how restoration practices affect the ecological development trajectories of newly established forests in NYC.

Drought-associated tree mortality: Global patterns and insights from tree-ring studies in the southwestern U.S.A

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Macalady, Alison Kelly

Forests play an important role in the earth system, regulating climate, maintaining biodiversity, and provisioning human communities with water, food and fuel. Interactions between climate and forest dynamics are not well constrained, and high uncertainty characterizes projections of global warming impacts on forests and associated ecosystem services. Recently observed tree mortality and forest die-off forewarn an acceleration of forest change with rising temperature and increased drought. However, the processes leading to tree death during drought are poorly understood, limiting our ability to anticipate future forest dynamics. The objective of this dissertation was to improve understanding of drought-associated tree mortality through literature synthesis and tree-ring studies on trees that survived and died during droughts in the southwestern USA. Specifically, this dissertation 1) documented global tree mortality patterns and identified emerging trends and research gaps; 2) quantified relationships between growth, climate, competition and mortality of pinon pine during droughts in New Mexico; 3) investigated tree defense anatomy as a potentially key element in pinon avoidance of death; and, 4) characterized the climate sensitivity of pinon resin ducts in order to gain insight into potential trends in tree defenses with climate variability and change. There has been an increase in studies reporting tree mortality linked to drought, heat, and the associated activity of insects and pathogens. Cases span the forested continents and occurred in water, light and temperature-limited forests. We hypothesized that increased tree mortality may be an emerging global phenomenon related to rising temperatures and drought (Appendix A). Recent radial growth was 53% higher on average in pinon that survived versus died during two episodes of drought-associated mortality, and statistical models of mortality risk based on average growth, growth variability, and abrupt growth

Trends in hospitalization for community-associated methicillin-resistant Staphylococcus aureus in New York City, 1997-2006: data from New York State's Statewide Planning and Research Cooperative System.

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Farr, Amanda M; Aden, Brandon; Weiss, Don; Nash, Denis; Marx, Melissa A

2012-07-01

To describe trends in hospitalizations with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infection in New York City over 10 years and to explore the demographics and comorbidities of patients hospitalized with CA-MRSA infections. Retrospective analysis of hospital discharges from New York State's Statewide Planning and Research Cooperative System database from 1997 to 2006. All patients greater than 1 year of age admitted to New York hospitals with diagnosis codes indicating MRSA who met the criteria for CA-MRSA on the basis of admission information and comorbidities. We determined hospitalization rates and compared demographics and comorbidities of patients hospitalized with CA-MRSA versus those hospitalized with all other non-MRSA diagnoses by multivariable logistic regression. Of 18,226 hospitalizations with an MRSA diagnosis over 10 years, 3,579 (20%) were classified as community-associated. The CA-MRSA hospitalization rate increased from 1.47 to 10.65 per 100,000 people overall from 1997 to 2006. Relative to non-MRSA hospitalizations, men, children, Bronx and Manhattan residents, the homeless, patients with human immunodeficiency virus (HIV) infection, and persons with diabetes had higher adjusted odds of CA-MRSA hospitalization. The CA-MRSA hospitalization rate appeared to increase between 1997 and 2006 in New York City, with residents of the Bronx and Manhattan, men, and persons with HIV infection or diabetes at increased odds of hospitalization with CA-MRSA. Further studies are needed to explore how changes in MRSA incidence, access to care, and other factors may have impacted these rates.

76 FR 40234 - Drawbridge Operation Regulations; Harlem River, New York City, NY

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2011-07-08

...-AA09 Drawbridge Operation Regulations; Harlem River, New York City, NY AGENCY: Coast Guard, DHS. ACTION... at mile 0.0, across the Harlem River at New York City, New York. This interim rule is necessary to... The 103rd Street (Wards Island) Pedestrian Bridge, across the Harlem River, mile 0.0, at New York City...

The Urban Forest and Ecosystem Services: Impacts on Urban Water, Heat, and Pollution Cycles at the Tree, Street, and City Scale.

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Livesley, S J; McPherson, G M; Calfapietra, C

2016-01-01

Many environmental challenges are exacerbated within the urban landscape, such as stormwater runoff and flood risk, chemical and particulate pollution of urban air, soil and water, the urban heat island, and summer heat waves. Urban trees, and the urban forest as a whole, can be managed to have an impact on the urban water, heat, carbon and pollution cycles. However, there is an increasing need for empirical evidence as to the magnitude of the impacts, both beneficial and adverse, that urban trees can provide and the role that climatic region and built landscape circumstance play in modifying those impacts. This special section presents new research that advances our knowledge of the ecological and environmental services provided by the urban forest. The 14 studies included provide a global perspective on the role of trees in towns and cities from five continents. Some studies provide evidence for the cooling benefit of the local microclimate in urban green space with and without trees. Other studies focus solely on the cooling benefit of urban tree transpiration at a mesoscale or on cooling from canopy shade at a street and pedestrian scale. Other studies are concerned with tree species differences in canopy interception of rainfall, water uptake from biofilter systems, and water quality improvements through nutrient uptake from stormwater runoff. Research reported here also considers both the positive and the negative impacts of trees on air quality, through the role of trees in removing air pollutants such as ozone as well as in releasing potentially harmful volatile organic compounds and allergenic particulates. A transdisciplinary framework to support future urban forest research is proposed to better understand and communicate the role of urban trees in urban biogeochemical cycles that are highly disturbed, highly managed, and of paramount importance to human health and well-being. Copyright © by the American Society of Agronomy, Crop Science Society of

Isoprene Emission Factors for Subtropical Street Trees for Regional Air Quality Modeling.

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Dunn-Johnston, Kristina A; Kreuzwieser, Jürgen; Hirabayashi, Satoshi; Plant, Lyndal; Rennenberg, Heinz; Schmidt, Susanne

2016-01-01

Evaluating the environmental benefits and consequences of urban trees supports their sustainable management in cities. Models such as i-Tree Eco enable decision-making by quantifying effects associated with particular tree species. Of specific concern are emissions of biogenic volatile organic compounds, particularly isoprene, that contribute to the formation of photochemical smog and ground level ozone. Few studies have quantified these potential disservices of urban trees, and current models predominantly use emissions data from trees that differ from those in our target region of subtropical Australia. The present study aimed (i) to quantify isoprene emission rates of three tree species that together represent 16% of the inventoried street trees in the target region; (ii) to evaluate outputs of the i-Tree Eco model using species-specific versus currently used, generic isoprene emission rates; and (iii) to evaluate the findings in the context of regional air quality. Isoprene emission rates of (Myrtaceae) and (Proteaceae) were 2.61 and 2.06 µg g dry leaf weight h, respectively, whereas (Sapindaceae) was a nonisoprene emitter. We substituted the generic isoprene emission rates with these three empirical values in i-Tree Eco, resulting in a 182 kg yr (97%) reduction in isoprene emissions, totaling 6284 kg yr when extrapolated to the target region. From these results we conclude that care has to be taken when using generic isoprene emission factors for urban tree models. We recommend that emissions be quantified for commonly planted trees, allowing decision-makers to select tree species with the greatest overall benefit for the urban environment. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Passive control potentials of trees and on-street parked cars in reduction of air pollution exposure in urban street canyons

International Nuclear Information System (INIS)

Abhijith, K.V.; Gokhale, Sharad

2015-01-01

This study investigates the passive-control-potentials of trees and on-street parked cars on pedestrian exposure to air pollutants in a street canyon using three-dimensional CFD. Since, according to some studies trees deteriorate air quality and cars parked roadside improve it, the combine as well as separate effects of trees and on-street parked cars have been examined. For this, different tree canopy layouts and parking configurations have been developed and pedestrian exposure for each has been analysed. The results showed, for example, tree crown with high porosity and low-stand density in combination with parallel or perpendicular car parking reduced the pedestrian exposure considerably. - Highlights: • Trees and on-street parked cars can manipulate pollutant levels in street canyons. • Low stand density trees with 0° or 90° car parking reduce pedestrian exposure. • Trees with medium crown, high porosity, low stand density reduce pollutant levels. - This study investigated the combination of trees and on-street parked cars to manipulate pollutant levels in urban street canyons to reduce pedestrian exposure

Estimating Potential Reductions in Premature Mortality in New York City From Raising the Minimum Wage to $15.

Science.gov (United States)

Tsao, Tsu-Yu; Konty, Kevin J; Van Wye, Gretchen; Barbot, Oxiris; Hadler, James L; Linos, Natalia; Bassett, Mary T

2016-06-01

To assess potential reductions in premature mortality that could have been achieved in 2008 to 2012 if the minimum wage had been $15 per hour in New York City. Using the 2008 to 2012 American Community Survey, we performed simulations to assess how the proportion of low-income residents in each neighborhood might change with a hypothetical $15 minimum wage under alternative assumptions of labor market dynamics. We developed an ecological model of premature death to determine the differences between the levels of premature mortality as predicted by the actual proportions of low-income residents in 2008 to 2012 and the levels predicted by the proportions of low-income residents under a hypothetical $15 minimum wage. A $15 minimum wage could have averted 2800 to 5500 premature deaths between 2008 and 2012 in New York City, representing 4% to 8% of total premature deaths in that period. Most of these avertable deaths would be realized in lower-income communities, in which residents are predominantly people of color. A higher minimum wage may have substantial positive effects on health and should be considered as an instrument to address health disparities.

Carbon Sequestration Estimation of Street Trees Based on Point Cloud from Vehicle-Borne Laser Scanning System

Science.gov (United States)

Zhao, Y.; Hu, Q.

2017-09-01

Continuous development of urban road traffic system requests higher standards of road ecological environment. Ecological benefits of street trees are getting more attention. Carbon sequestration of street trees refers to the carbon stocks of street trees, which can be a measurement for ecological benefits of street trees. Estimating carbon sequestration in a traditional way is costly and inefficient. In order to solve above problems, a carbon sequestration estimation approach for street trees based on 3D point cloud from vehicle-borne laser scanning system is proposed in this paper. The method can measure the geometric parameters of a street tree, including tree height, crown width, diameter at breast height (DBH), by processing and analyzing point cloud data of an individual tree. Four Chinese scholartree trees and four camphor trees are selected for experiment. The root mean square error (RMSE) of tree height is 0.11m for Chinese scholartree and 0.02m for camphor. Crown widths in X direction and Y direction, as well as the average crown width are calculated. And the RMSE of average crown width is 0.22m for Chinese scholartree and 0.10m for camphor. The last calculated parameter is DBH, the RMSE of DBH is 0.5cm for both Chinese scholartree and camphor. Combining the measured geometric parameters and an appropriate carbon sequestration calculation model, the individual tree's carbon sequestration will be estimated. The proposed method can help enlarge application range of vehicle-borne laser point cloud data, improve the efficiency of estimating carbon sequestration, construct urban ecological environment and manage landscape.

Urban warming drives insect pest abundance on street trees.

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Emily K Meineke

Full Text Available Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer.

Vulnerability of Amazon forests to storm-driven tree mortality

Science.gov (United States)

Negrón-Juárez, Robinson I.; Holm, Jennifer A.; Magnabosco Marra, Daniel; Rifai, Sami W.; Riley, William J.; Chambers, Jeffrey Q.; Koven, Charles D.; Knox, Ryan G.; McGroddy, Megan E.; Di Vittorio, Alan V.; Urquiza-Muñoz, Jose; Tello-Espinoza, Rodil; Alegria Muñoz, Waldemar; Ribeiro, Gabriel H. P. M.; Higuchi, Niro

2018-05-01

Tree mortality is a key driver of forest community composition and carbon dynamics. Strong winds associated with severe convective storms are dominant natural drivers of tree mortality in the Amazon. Why forests vary with respect to their vulnerability to wind events and how the predicted increase in storm events might affect forest ecosystems within the Amazon are not well understood. We found that windthrows are common in the Amazon region extending from northwest (Peru, Colombia, Venezuela, and west Brazil) to central Brazil, with the highest occurrence of windthrows in the northwest Amazon. More frequent winds, produced by more frequent severe convective systems, in combination with well-known processes that limit the anchoring of trees in the soil, help to explain the higher vulnerability of the northwest Amazon forests to winds. Projected increases in the frequency and intensity of convective storms in the Amazon have the potential to increase wind-related tree mortality. A forest demographic model calibrated for the northwestern and the central Amazon showed that northwestern forests are more resilient to increased wind-related tree mortality than forests in the central Amazon. Our study emphasizes the importance of including wind-related tree mortality in model simulations for reliable predictions of the future of tropical forests and their effects on the Earth’ system.

Effects of acidic deposition and soil acidification on sugar maple trees in the Adirondack Mountains, New York

Science.gov (United States)

Sullivan, Timothy J.; Lawrence, Gregory B.; Bailey, Scott W.; McDonnell, Todd C.; Beier, Colin M.; Weathers, K.C.; McPherson, G.T.; Bishop, Daniel A.

2013-01-01

We documented the effects of acidic atmospheric deposition and soil acidification on the canopy health, basal area increment, and regeneration of sugar maple (SM) trees across the Adirondack region of New York State, in the northeastern United States, where SM are plentiful but not well studied and where widespread depletion of soil calcium (Ca) has been documented. Sugar maple is a dominant canopy species in the Adirondack Mountain ecoregion, and it has a high demand for Ca. Trees in this region growing on soils with poor acid–base chemistry (low exchangeable Ca and % base saturation [BS]) that receive relatively high levels of atmospheric sulfur and nitrogen deposition exhibited a near absence of SM seedling regeneration and lower crown vigor compared with study plots with relatively high exchangeable Ca and BS and lower levels of acidic deposition. Basal area increment averaged over the 20th century was correlated (p < 0.1) with acid–base chemistry of the Oa, A, and upper B soil horizons. A lack of Adirondack SM regeneration, reduced canopy condition, and possibly decreased basal area growth over recent decades are associated with low concentrations of nutrient base cations in this region that has undergone soil Ca depletion from acidic deposition.

Trees grow on money: Urban tree canopy cover and environmental justice

Science.gov (United States)

Kirsten Schwarz; Michail Fragkias; Christopher G. Boone; Weiqi Zhou; Melissa McHale; J. Morgan Grove; Jarlath O' Neil-Dunne; Joseph P. McFadden; Geoffrey L. Buckley; Dan Childers; Laura Ogden; Stephanie Pincetl; Diane Pataki; Ali Whitmer; Mary L. Cadenasso; Steven Arthur. Loiselle

2015-01-01

This study examines the distributional equity of urban tree canopy (UTC) cover for Baltimore, MD, Los Angeles, CA, New York, NY, Philadelphia, PA, Raleigh, NC, Sacramento, CA, and Washington, D.C. using high spatial resolution land cover data and census data. Data are analyzed at the Census Block Group levels using Spearman’s correlation, ordinary least squares...

Summer heat and mortality in New York City: how hot is too hot?

Science.gov (United States)

Metzger, Kristina B; Ito, Kazuhiko; Matte, Thomas D

2010-01-01

To assess the public health risk of heat waves and to set criteria for alerts for -excessive heat, various meteorologic metrics and models are used in different jurisdictions, generally without systematic comparisons of alternatives. We report such an analysis for New York City that compared maximum heat index with alternative metrics in models to predict daily variation in warm-season natural-cause mortality from 1997 through 2006. We used Poisson time-series generalized linear models and generalized additive models to estimate weather-mortality relationships using various metrics, lag and averaging times, and functional forms and compared model fit. A model that included cubic functions of maximum heat index on the same and each of the previous 3 days provided the best fit, better than models using maximum, minimum, or average temperature, or spatial synoptic classification (SSC) of weather type. We found that goodness of fit and maximum heat index-mortality functions were similar using parametric and nonparametric models. Same-day maximum heat index was linearly related to mortality risk across its range. The slopes at lags of 1, 2, and 3 days were flat across moderate values but increased sharply between maximum heat index of 95 degrees F and 100 degrees F (35-38 degrees C). SSC or other meteorologic variables added to the maximum heat index model moderately improved goodness of fit, with slightly attenuated maximum heat index-mortality functions. In New York City, maximum heat index performed similarly to alternative and more complex metrics in estimating mortality risk during hot weather. The linear relationship supports issuing heat alerts in New York City when the heat index is forecast to exceed approximately 95-100 degrees F. Periodic city-specific analyses using recent data are recommended to evaluate public health risks from extreme heat.

Urban Ecological Stewardship: Understanding the Structure, Function and Network of Community-based Urban Land Management

Directory of Open Access Journals (Sweden)

Lindsay K. Campbell

2008-01-01

Full Text Available Urban environmental stewardship activities are on the rise in cities throughout the Northeast. Groups participating in stewardship activities range in age, size, and geography and represent an increasingly complex and dynamic arrangement of civil society, government and business sectors. To better understand the structure, function and network of these community-based urban land managers, an assessment was conducted in 2004 by the research subcommittee of the Urban Ecology Collaborative. The goal of the assessment was to better understand the role of stewardship organizations engaged in urban ecology initiatives in selected major cities in the Northeastern U.S.: Boston, New Haven, New York City, Pittsburgh, Baltimore, and Washington, D.C. A total of 135 active organizations participated in this assessment. Findings include the discovery of a dynamic social network operating within cities, and a reserve of social capital and expertise that could be better utilized. Although often not the primary land owner, stewardship groups take an increasingly significant responsibility for a wide range of land use types including street and riparian corridors, vacant lots, public parks and gardens, green roofs, etc. Responsibilities include the delivery of public programs as well as daily maintenance and fundraising support. While most of the environmental stewardship organizations operate on staffs of zero or fewer than ten, with small cohorts of community volunteers, there is a significant difference in the total amount of program funding. Nearly all respondents agree that committed resources are scarce and insufficient with stewards relying upon and potentially competing for individual donations, local foundations, and municipal support. This makes it a challenge for the groups to grow beyond their current capacity and to develop long-term programs critical to resource management and education. It also fragments groups, making it difficult for planners and

Citygml and the Streets of New York - a Proposal for Detailed Street Space Modelling

Science.gov (United States)

Beil, C.; Kolbe, T. H.

2017-10-01

Three-dimensional semantic city models are increasingly used for the analysis of large urban areas. Until now the focus has mostly been on buildings. Nonetheless many applications could also benefit from detailed models of public street space for further analysis. However, there are only few guidelines for representing roads within city models. Therefore, related standards dealing with street modelling are examined and discussed. Nearly all street representations are based on linear abstractions. However, there are many use cases that require or would benefit from the detailed geometrical and semantic representation of street space. A variety of potential applications for detailed street space models are presented. Subsequently, based on related standards as well as on user requirements, a concept for a CityGML-compliant representation of street space in multiple levels of detail is developed. In the course of this process, the CityGML Transportation model of the currently valid OGC standard CityGML2.0 is examined to discover possibilities for further developments. Moreover, a number of improvements are presented. Finally, based on open data sources, the proposed concept is implemented within a semantic 3D city model of New York City generating a detailed 3D street space model for the entire city. As a result, 11 thematic classes, such as roadbeds, sidewalks or traffic islands are generated and enriched with a large number of thematic attributes.

Examining School Leadership in New York City Community Schools

Science.gov (United States)

Campo, Stacey Elizabeth

2017-01-01

The community school model is rooted in John Dewey's (1902) conceptualization of the public school as a hub for the community. This work has evolved over a hundred years and recently experienced prominence in the public eye as a fundamental component of New York City's school turnaround policy. This dissertation describes findings and…

Competition and climate affects US hardwood-forest tree mortality

Science.gov (United States)

Daniel A. Yaussy; Louis R. Iverson; Stephen N. Matthews

2013-01-01

Individual-tree measurements have been collected periodically on sites established in Kentucky, New York, Ohio, and Pennsylvania to investigate the effects of thinning on the growth and yield of valuable hardwood species. These plots were installed between 1959 and 1985. The long-term characteristics of this data set of 47,853 trees allowed us to investigate potential...

National Assessment of Tree City USA Participation According to Geography and Socioeconomic Characteristics

Science.gov (United States)

Tree City USA is a national program that recognizes municipal commitment to community forestry. In return for meeting program requirements, Tree City USA participants expect social, economic, and/or environmental benefits. Understandingthe geographic distribution and socioeconomi...

Chapter 5 - Tree Mortality

Science.gov (United States)

Mark J. Ambrose

2014-01-01

Tree mortality is a natural process in all forest ecosystems. Extremely high mortality, however, can also be an indicator of forest health issues. On a regional scale, high mortality levels may indicate widespread insect or disease problems. High mortality may also occur if a large proportion of the forest in a particular region is made up of older, senescent stands....

Patterns and Drivers of Tree Mortality in Iberian Forests: Climatic Effects Are Modified by Competition

Science.gov (United States)

Ruiz-Benito, Paloma; Lines, Emily R.; Gómez-Aparicio, Lorena; Zavala, Miguel A.; Coomes, David A.

2013-01-01

Tree mortality is a key process underlying forest dynamics and community assembly. Understanding how tree mortality is driven by simultaneous drivers is needed to evaluate potential effects of climate change on forest composition. Using repeat-measure information from c. 400,000 trees from the Spanish Forest Inventory, we quantified the relative importance of tree size, competition, climate and edaphic conditions on tree mortality of 11 species, and explored the combined effect of climate and competition. Tree mortality was affected by all of these multiple drivers, especially tree size and asymmetric competition, and strong interactions between climate and competition were found. All species showed L-shaped mortality patterns (i.e. showed decreasing mortality with tree size), but pines were more sensitive to asymmetric competition than broadleaved species. Among climatic variables, the negative effect of temperature on tree mortality was much larger than the effect of precipitation. Moreover, the effect of climate (mean annual temperature and annual precipitation) on tree mortality was aggravated at high competition levels for all species, but especially for broadleaved species. The significant interaction between climate and competition on tree mortality indicated that global change in Mediterranean regions, causing hotter and drier conditions and denser stands, could lead to profound effects on forest structure and composition. Therefore, to evaluate the potential effects of climatic change on tree mortality, forest structure must be considered, since two systems of similar composition but different structure could radically differ in their response to climatic conditions. PMID:23451096

Rapid decay of tree-community composition in Amazonian forest fragments

Science.gov (United States)

Laurance, William F.; Nascimento, Henrique E. M.; Laurance, Susan G.; Andrade, Ana; Ribeiro, José E. L. S.; Giraldo, Juan Pablo; Lovejoy, Thomas E.; Condit, Richard; Chave, Jerome; Harms, Kyle E.; D'Angelo, Sammya

2006-01-01

Forest fragmentation is considered a greater threat to vertebrates than to tree communities because individual trees are typically long-lived and require only small areas for survival. Here we show that forest fragmentation provokes surprisingly rapid and profound alterations in Amazonian tree-community composition. Results were derived from a 22-year study of exceptionally diverse tree communities in 40 1-ha plots in fragmented and intact forests, which were sampled repeatedly before and after fragment isolation. Within these plots, trajectories of change in abundance were assessed for 267 genera and 1,162 tree species. Abrupt shifts in floristic composition were driven by sharply accelerated tree mortality and recruitment within ≈100 m of fragment margins, causing rapid species turnover and population declines or local extinctions of many large-seeded, slow-growing, and old-growth taxa; a striking increase in a smaller set of disturbance-adapted and abiotically dispersed species; and significant shifts in tree size distributions. Even among old-growth trees, species composition in fragments is being restructured substantially, with subcanopy species that rely on animal seed-dispersers and have obligate outbreeding being the most strongly disadvantaged. These diverse changes in tree communities are likely to have wide-ranging impacts on forest architecture, canopy-gap dynamics, plant–animal interactions, and forest carbon storage. PMID:17148598

Implications of tree planting on pollutant dispersion in street canyons

NARCIS (Netherlands)

Gromke, C.B.; Ruck, B.

2009-01-01

Traffic pollutant dispersion processes inside urban street canyons with avenue-like tree planting have been studied in wind tunnel experiments. Tree planting of different crown porosities and their effects on the pollutant concentrations at the canyon walls have been investigated for wind

Integration of ecological indices in the multivariate evaluation of an urban inventory of street trees

Science.gov (United States)

J. Grabinsky; A. Aldama; A. Chacalo; H. J. Vazquez

2000-01-01

Inventory data of Mexico City's street trees were studied using classical statistical arboricultural and ecological statistical approaches. Multivariate techniques were applied to both. Results did not differ substantially and were complementary. It was possible to reduce inventory data and to group species, boroughs, blocks, and variables.

Remotely sensed predictors of conifer tree mortality during severe drought

Science.gov (United States)

Brodrick, P. G.; Asner, G. P.

2017-11-01

Widespread, drought-induced forest mortality has been documented on every forested continent over the last two decades, yet early pre-mortality indicators of tree death remain poorly understood. Remotely sensed physiological-based measures offer a means for large-scale analysis to understand and predict drought-induced mortality. Here, we use laser-guided imaging spectroscopy from multiple years of aerial surveys to assess the impact of sustained canopy water loss on tree mortality. We analyze both gross canopy mortality in 2016 and the change in mortality between 2015 and 2016 in millions of sampled conifer forest locations throughout the Sierra Nevada mountains in California. On average, sustained water loss and gross mortality are strongly related, and year-to-year water loss within the drought indicates subsequent mortality. Both relationships are consistent after controlling for location and tree community composition, suggesting that these metrics may serve as indicators of mortality during a drought.

A Voxel-Based Method for Automated Identification and Morphological Parameters Estimation of Individual Street Trees from Mobile Laser Scanning Data

Directory of Open Access Journals (Sweden)

Hongxing Liu

2013-01-01

Full Text Available As an important component of urban vegetation, street trees play an important role in maintenance of environmental quality, aesthetic beauty of urban landscape, and social service for inhabitants. Acquiring accurate and up-to-date inventory information for street trees is required for urban horticultural planning, and municipal urban forest management. This paper presents a new Voxel-based Marked Neighborhood Searching (VMNS method for efficiently identifying street trees and deriving their morphological parameters from Mobile Laser Scanning (MLS point cloud data. The VMNS method consists of six technical components: voxelization, calculating values of voxels, searching and marking neighborhoods, extracting potential trees, deriving morphological parameters, and eliminating pole-like objects other than trees. The method is validated and evaluated through two case studies. The evaluation results show that the completeness and correctness of our method for street tree detection are over 98%. The derived morphological parameters, including tree height, crown diameter, diameter at breast height (DBH, and crown base height (CBH, are in a good agreement with the field measurements. Our method provides an effective tool for extracting various morphological parameters for individual street trees from MLS point cloud data.

Trees as environmental modifier to improve street canyon for pedestrian activities in Muscat

Science.gov (United States)

Khudhayer, Wael A.; Shaaban, Awni K.; Sukor, Nur Sabahiah Abdul

2017-10-01

Street shading efficiency is a function of orientation and profile proportion of its height to width. Under high sun altitude conditions, minimization of solar irradiance within the urban environment may often be a significant criterion in urban design. This reduction in solar irradiance achieved when the obstruction angle is large (high H/W ratio, H=height, W=width). High H/W values often lessen the solar access to streets. The horizontal sprawl of Muscat region is an example of low H/W ratio represented the remarkable challenge that causes the lack of shading rates in the urban street. This characteristic proliferates the negative impact on the pedestrian activities in the urban street. This research aims to improve the morphology of the street to promote the pedestrian behavior. The amendment based on suggesting different configurations of trees to increase effective shading of the urban street in Muscat. The street canyon abstracted into a virtual elongated channel formed of floor and walls of equal heights on both sides. Four street orientations (E/W, N/S, NE/SW, NW/SE) and three H/W ratio (0.5,1 and 2) are considered sufficient representative of street typologies. A mathematical model developed for calculation of shading efficiency of each street canyon. The trees assumed in this study as canyon's modifier to adjust the low H/W ratio of a street canyon to a higher one. Local trees and other plants in Muscat were studied concerning their morphology. The analysis selected two case study in Muscat to investigate the shading performance of their street canyons subsequently propose the modifications to improve it. The research concluded that the suggested changes of the street canyon by using a particular type of trees could increase the H/W ratio of street canyon significantly.

Trees in urban street canyons and their impact on the dispersion of automobile exhausts

OpenAIRE

Gromke, Christof; Ruck, Bodo

2007-01-01

The aim of the present study is to clarify the influence of trees on the dispersion of automobile exhausts in urban street canyons. For this purpose, measurements have been performed with a small scale wind tunnel model of an idealized, isolated street canyon with model trees placed along the canyon center axis. Sulfur hexafluoride (SF6) was released from a line source embedded in the street surface, simulating vehicle exhaust emissions. The influence of various tree planting arrangements on ...

Cooling and energy saving potentials of shade trees and urban lawns in a desert city

International Nuclear Information System (INIS)

Wang, Zhi-Hua; Zhao, Xiaoxi; Yang, Jiachuan; Song, Jiyun

2016-01-01

Highlights: • We developed a numerical framework incorporating trees in an urban canopy model. • Shade trees have more prominent energy saving potential than urban lawns. • The trade-off between water-energy is a key for urban landscape management. • Urban vegetation can significantly alleviate outdoor thermal stress. - Abstract: The use of urban vegetation in cities is a common landscape planning strategy to alleviate the heat island effect as well as to enhance building energy efficiency. The presence of trees in street canyons can effectively reduce environmental temperature via radiative shading. However, resolving shade trees in urban land surface models presents a major challenge in numerical models, especially in predicting the radiative heat exchange in canyons. In this paper, we develop a new numerical framework by incorporating shade trees into an advanced single-layer urban canopy model. This novel numerical framework is applied to Phoenix metropolitan area to investigate the cooling effect of different urban vegetation types and their potentials in saving building energy. It is found that the cooling effect by shading from trees is more significant than that by evapotranspiration from lawns, leading to a considerable saving of cooling load. In addition, analysis of human thermal comfort shows that urban vegetation plays a crucial role in creating a comfortable living environment, especially for cities located in arid or semi-arid region.

Study of traffic-related pollutant removal from street canyon with trees: dispersion and deposition perspective.

Science.gov (United States)

Morakinyo, Tobi Eniolu; Lam, Yun Fat

2016-11-01

Numerical experiments involving street canyons of varying aspect ratio with traffic-induced pollutants (PM 2.5 ) and implanted trees of varying aspect ratio, leaf area index, leaf area density distribution, trunk height, tree-covered area, and tree planting pattern under different wind conditions were conducted using a computational fluid dynamics (CFD) model, ENVI-met. Various aspects of dispersion and deposition were investigated, which include the influence of various tree configurations and wind condition on dispersion within the street canyon, pollutant mass at the free stream layer and street canyon, and comparison between mass removal by surface (leaf) deposition and mass enhancement due to the presence of trees. Results revealed that concentration level was enhanced especially within pedestrian level in street canyons with trees relative to their tree-free counterparts. Additionally, we found a dependence of the magnitude of concentration increase (within pedestrian level) and decrease (above pedestrian level) due to tree configuration and wind condition. Furthermore, we realized that only ∼0.1-3 % of PM 2.5 was dispersed to the free stream layer while a larger percentage (∼97 %) remained in the canyon, regardless of its aspect ratio, prevailing wind condition, and either tree-free or with tree (of various configuration). Lastly, results indicate that pollutant removal due to deposition on leaf surfaces is potentially sufficient to counterbalance the enhancement of PM 2.5 by such trees under some tree planting scenarios and wind conditions.

New York City, New York: Solar in Action (Brochure)

Energy Technology Data Exchange (ETDEWEB)

2011-10-01

This brochure provides an overview of the challenges and successes of New York City, NY, a 2007 Solar America City awardee, on the path toward becoming a solar-powered community. Accomplishments, case studies, key lessons learned, and local resource information are given.

Stewardship matters: Case studies in establishment success of urban trees

Science.gov (United States)

Lara A. Roman; Lindsey A. Walker; Catherine M. Martineau; David J. Muffly; Susan A. MacQueen; Winnie Harris

2015-01-01

Urban tree planting initiatives aim to provide ecosystem services that materialize decades after planting, therefore understanding tree survival and growth is essential to evaluating planting program performance. Tree mortality is relatively high during the establishment phase, the first few years after planting. Qualitative assessments of programs with particularly...

Bumble Bee Abundance in New York City Community Gardens: Implications for Urban Agriculture

Directory of Open Access Journals (Sweden)

Gail A. Langellotto

2009-01-01

Full Text Available A variety of crops are grown in New York City community gardens. Although the production of many crops benefits from pollination by bees, little is known about bee abundance in urban community gardens or which crops are specifically dependent on bee pollination. In 2005, we compiled a list of crop plants grown within 19 community gardens in New York City and classified these plants according to their dependence on bee pollination. In addition, using mark-recapture methods, we estimated the abundance of a potentially important pollinator within New York City urban gardens, the common eastern bumble bee (Bombus impatiens. This species is currently recognized as a valuable commercial pollinator of greenhouse crops. However, wild populations of B. impatiens are abundant throughout its range, including in New York City community gardens, where it is the most abundant native bee species present and where it has been observed visiting a variety of crop flowers. We conservatively counted 25 species of crop plants in 19 surveyed gardens. The literature suggests that 92% of these crops are dependent, to some degree, on bee pollination in order to set fruit or seed. Bombus impatiens workers were observed visiting flowers of 78% of these pollination-dependent crops. Estimates of the number of B. impatiens workers visiting individual gardens during the study period ranged from 3 to 15 bees per 100 m2 of total garden area and 6 to 29 bees per 100 m2 of garden floral area. Of 229 B. impatiens workers marked, all recaptured individuals (45% were found in gardens where they were initially marked. These results indicate an abundance of B. impatiens workers within New York City community gardens and suggest that, at least for certain time periods, many individual workers forage within single gardens. Both findings suggest that B. impatiens may be an especially important pollinator of several common crops grown within community gardens and other urban green spaces

Intra-urban biomonitoring: Source apportionment using tree barks to identify air pollution sources.

Science.gov (United States)

Moreira, Tiana Carla Lopes; de Oliveira, Regiani Carvalho; Amato, Luís Fernando Lourenço; Kang, Choong-Min; Saldiva, Paulo Hilário Nascimento; Saiki, Mitiko

2016-05-01

It is of great interest to evaluate if there is a relationship between possible sources and trace elements using biomonitoring techniques. In this study, tree bark samples of 171 trees were collected using a biomonitoring technique in the inner city of São Paulo. The trace elements (Al, Ba, Ca, Cl, Cu, Fe, K, Mg, Mn, Na, P, Rb, S, Sr and Zn) were determined by the energy dispersive X-ray fluorescence (EDXRF) spectrometry. The Principal Component Analysis (PCA) was applied to identify the plausible sources associated with tree bark measurements. The greatest source was vehicle-induced non-tailpipe emissions derived mainly from brakes and tires wear-out and road dust resuspension (characterized with Al, Ba, Cu, Fe, Mn and Zn), which was explained by 27.1% of the variance, followed by cement (14.8%), sea salt (11.6%) and biomass burning (10%), and fossil fuel combustion (9.8%). We also verified that the elements related to vehicular emission showed different concentrations at different sites of the same street, which might be helpful for a new street classification according to the emission source. The spatial distribution maps of element concentrations were obtained to evaluate the different levels of pollution in streets and avenues. Results indicated that biomonitoring techniques using tree bark can be applied to evaluate dispersion of air pollution and provide reliable data for the further epidemiological studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Urban tree mortality: a primer on demographic approaches

Science.gov (United States)

Lara A. Roman; John J. Battles; Joe R. McBride

2016-01-01

Realizing the benefits of tree planting programs depends on tree survival. Projections of urban forest ecosystem services and cost-benefit analyses are sensitive to assumptions about tree mortality rates. Long-term mortality data are needed to improve the accuracy of these models and optimize the public investment in tree planting. With more accurate population...

New perspectives on the ecology of tree structure and tree communities through terrestrial laser scanning.

Science.gov (United States)

Malhi, Yadvinder; Jackson, Tobias; Patrick Bentley, Lisa; Lau, Alvaro; Shenkin, Alexander; Herold, Martin; Calders, Kim; Bartholomeus, Harm; Disney, Mathias I

2018-04-06

Terrestrial laser scanning (TLS) opens up the possibility of describing the three-dimensional structures of trees in natural environments with unprecedented detail and accuracy. It is already being extensively applied to describe how ecosystem biomass and structure vary between sites, but can also facilitate major advances in developing and testing mechanistic theories of tree form and forest structure, thereby enabling us to understand why trees and forests have the biomass and three-dimensional structure they do. Here we focus on the ecological challenges and benefits of understanding tree form, and highlight some advances related to capturing and describing tree shape that are becoming possible with the advent of TLS. We present examples of ongoing work that applies, or could potentially apply, new TLS measurements to better understand the constraints on optimization of tree form. Theories of resource distribution networks, such as metabolic scaling theory, can be tested and further refined. TLS can also provide new approaches to the scaling of woody surface area and crown area, and thereby better quantify the metabolism of trees. Finally, we demonstrate how we can develop a more mechanistic understanding of the effects of avoidance of wind risk on tree form and maximum size. Over the next few years, TLS promises to deliver both major empirical and conceptual advances in the quantitative understanding of trees and tree-dominated ecosystems, leading to advances in understanding the ecology of why trees and ecosystems look and grow the way they do.

Effects of street tree shade on asphalt concrete pavement performance

Science.gov (United States)

E.G. McPherson; J. Muchnick

2005-01-01

Forty-eight street segments were paired into 24 high-and low-shade pairs in Modesto, California, U.S. Field data were collected to calculate a Pavement Condition Index (PCI) and Tree Shade Index (TSI) for each segment. Statistical analyses found that greater PCI was associated with greater TSI, indicating that tree shade was partially responsible for reduced pavement...

Legionnaires' Disease Outbreaks and Cooling Towers, New York City, New York, USA.

Science.gov (United States)

Fitzhenry, Robert; Weiss, Don; Cimini, Dan; Balter, Sharon; Boyd, Christopher; Alleyne, Lisa; Stewart, Renee; McIntosh, Natasha; Econome, Andrea; Lin, Ying; Rubinstein, Inessa; Passaretti, Teresa; Kidney, Anna; Lapierre, Pascal; Kass, Daniel; Varma, Jay K

2017-11-01

The incidence of Legionnaires' disease in the United States has been increasing since 2000. Outbreaks and clusters are associated with decorative, recreational, domestic, and industrial water systems, with the largest outbreaks being caused by cooling towers. Since 2006, 6 community-associated Legionnaires' disease outbreaks have occurred in New York City, resulting in 213 cases and 18 deaths. Three outbreaks occurred in 2015, including the largest on record (138 cases). Three outbreaks were linked to cooling towers by molecular comparison of human and environmental Legionella isolates, and the sources for the other 3 outbreaks were undetermined. The evolution of investigation methods and lessons learned from these outbreaks prompted enactment of a new comprehensive law governing the operation and maintenance of New York City cooling towers. Ongoing surveillance and program evaluation will determine if enforcement of the new cooling tower law reduces Legionnaires' disease incidence in New York City.

Spatial distribution assessment of particulate matter in an urban street canyon using biomagnetic leaf monitoring of tree crown deposited particles

International Nuclear Information System (INIS)

Hofman, Jelle; Stokkaer, Ines; Snauwaert, Lies; Samson, Roeland

2013-01-01

Recently, biomagnetic monitoring of tree leaves has proven to be a good estimator for ambient particulate concentration. This paper investigates the usefulness of biomagnetic leaf monitoring of crown deposited particles to assess the spatial PM distribution inside individual tree crowns and an urban street canyon in Ghent (Belgium). Results demonstrate that biomagnetic monitoring can be used to assess spatial PM variations, even within single tree crowns. SIRM values decrease exponentially with height and azimuthal effects are obtained for wind exposed sides of the street canyon. Edge and canyon trees seem to be exposed differently. As far as we know, this study is the first to present biomagnetic monitoring results of different trees within a single street canyon. The results not only give valuable insights into the spatial distribution of particulate matter inside tree crowns and a street canyon, but also offer a great potential as validation tool for air quality modelling. Highlights: ► Spatial distribution of tree crown deposited PM was evaluated. ► SIRM values decrease exponentially with height. ► Azimuthal effects were observed at wind exposed sides of the street canyon. ► Edge and canyon trees seem to be exposed differently. ► Biomagnetic monitoring offers a great potential as validation of air quality models. -- Biomagnetic leaf monitoring provides useful insights into the spatial distribution of particulates inside individual tree crowns and an urban street canyon in Ghent (Belgium)

THE MICROCLIMATE OF DIFFERENT LANDSCAPE ARRANGEMENTS IN STREET TREES OF CURITIBA-PR STATE

Directory of Open Access Journals (Sweden)

Angeline Martini

2017-01-01

Full Text Available Microclimate improvement is frequently stated as one of the benefits generated by urban forestry. However, there are still few studies that quantitatively approach this issue. The goal of this study was to quantify the microclimatic difference between streets with and without trees, for each season and landscaping type. For this, three locations were chosen. Each location showed different species composing landscaping types: Tipuana tipu, Handroanthus chrysotrichus, and Lafoensia pacari with Parapiptadenia rigida . A Kestrel® mini station was placed on a street with trees and another one on a street without trees. The daily period for collecting this data was from 9 a.m. to 3 p.m., with monitoring intervals of 1 minute, repeated during the four seasons of the year, beginning in the winter of 2011. The microclimatic variables analyzed were temperature, relative humidity and wind speed. The results indicated that the streets with trees always had lower temperatures and greater relative humidity values than the streets without trees. The greatest temperature difference was observed in the summer (2.5 o C and the smallest one in the winter (1.2 o C. For relative humidity, the differences were between 6.4% (spring and 5.6% (winter, and for wind speed the greatest difference was found in the winter (0.17m/s. Landscaping that uses Tipuana tipu on both sides of the street, planted in a way such as to make their canopies entangle and form a tunnel, is the best choice for a more pleasant microclimate in all seasons of the year.

CO2 absorption/emission and aerodynamic effects of trees on the concentrations in a street canyon in Guangzhou, China

International Nuclear Information System (INIS)

Li, Jian-Feng; Zhan, Jie-Min; Li, Y.S.; Wai, Onyx W.H.

2013-01-01

In this paper, the effects of trees on CO 2 concentrations in a street canyon in Guangzhou, China are examined by Computational Fluid Dynamics (CFD) simulations of the concentration distribution, taking into account both the CO 2 absorption/emission and aerodynamic effects of trees. Simulation results show that, under a 2 m/s southerly prevailing wind condition, CO 2 absorption by trees will reduce the CO 2 concentration by around 2.5% in the daytime and at the same time the trees' resistance will increase the difference of CO 2 concentrations in the street and at the inflow by 43%. As the traffic density increases to 50 vehicles/min, the effect of trees on the ambient CO 2 concentration will change from positive to negative. At night, trees have a negative effect on the concentration in the street canyon mainly because of their resistance to airflow. When environmental wind changes, the effect of trees will be different. -- Highlights: ► The trees affect CO 2 concentrations in a street canyon. ► Both the CO 2 absorption and flow resistance of trees are significant factors by day. ► As the emissions of CO 2 increase, the effect of trees will become negative. ► At night, trees have a negative effect on CO 2 concentration due to the resistance. -- The effects of trees on CO 2 concentrations in a street canyon are examined by CFD simulations, taking into account both the CO 2 absorption/emission and aerodynamic effects of trees

The contribution of competition to tree mortality in old-growth coniferous forests

Science.gov (United States)

Das, A.; Battles, J.; Stephenson, N.L.; van Mantgem, P.J.

2011-01-01

Competition is a well-documented contributor to tree mortality in temperate forests, with numerous studies documenting a relationship between tree death and the competitive environment. Models frequently rely on competition as the only non-random mechanism affecting tree mortality. However, for mature forests, competition may cease to be the primary driver of mortality.We use a large, long-term dataset to study the importance of competition in determining tree mortality in old-growth forests on the western slope of the Sierra Nevada of California, U.S.A. We make use of the comparative spatial configuration of dead and live trees, changes in tree spatial pattern through time, and field assessments of contributors to an individual tree's death to quantify competitive effects.Competition was apparently a significant contributor to tree mortality in these forests. Trees that died tended to be in more competitive environments than trees that survived, and suppression frequently appeared as a factor contributing to mortality. On the other hand, based on spatial pattern analyses, only three of 14 plots demonstrated compelling evidence that competition was dominating mortality. Most of the rest of the plots fell within the expectation for random mortality, and three fit neither the random nor the competition model. These results suggest that while competition is often playing a significant role in tree mortality processes in these forests it only infrequently governs those processes. In addition, the field assessments indicated a substantial presence of biotic mortality agents in trees that died.While competition is almost certainly important, demographics in these forests cannot accurately be characterized without a better grasp of other mortality processes. In particular, we likely need a better understanding of biotic agents and their interactions with one another and with competition. ?? 2011.

Pollutant Concentrations in Street Canyons of Different Aspect Ratio with Avenues of Trees for Various Wind Directions

Science.gov (United States)

Gromke, Christof; Ruck, Bodo

2012-07-01

This study summarizes the effects of avenues of trees in urban street canyons on traffic pollutant dispersion. We describe various wind-tunnel experiments with different tree-avenue models in combination with variations in street-canyon aspect ratio W/ H (with W the street-canyon width and H the building height) and approaching wind direction. Compared to tree-free street canyons, in general, higher pollutant concentrations are found. Avenues of trees do not suppress canyon vortices, although the air ventilation in canyons is hindered significantly. For a perpendicular wind direction, increases in wall-average and wall-maximum concentrations at the leeward canyon wall and decreases in wall-average concentrations at the windward wall are found. For oblique and perpendicular wind directions, increases at both canyon walls are obtained. The strongest effects of avenues of trees on traffic pollutant dispersion are observed for oblique wind directions for which also the largest concentrations at the canyon walls are found. Thus, the prevailing assumption that attributes the most harmful dispersion conditions to a perpendicular wind direction does not hold for street canyons with avenues of trees. Furthermore, following dimensional analysis, an estimate of the normalized wall-maximum traffic pollutant concentration in street canyons with avenues of trees is derived.

Association of neighborhood-level factors with hospitalization for community-associated methicillin-resistant Staphylococcus aureus, New York City, 2006: a multilevel observational study.

Science.gov (United States)

Farr, Amanda M; Marx, Melissa A; Weiss, Don; Nash, Denis

2013-02-13

Hospitalizations with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infection have increased in New York City, with substantial geographic variation across neighborhoods. While individual-level risk factors, such as age, sex, HIV infection, and diabetes have been described, the role of neighborhood-level factors (e.g., neighborhood HIV prevalence or income) has not been examined. To explore plausible neighborhood-level factors associated with CA-MRSA-related hospitalizations, a retrospective analysis was conducted using New York City hospital discharges from 2006 and New York City-specific survey and health department surveillance data. CA-MRSA-related hospitalizations were identified using diagnosis codes and admission information. Associations were determined by using sex-specific multilevel logistic regression. The CA-MRSA hospitalization rate varied by more than six-fold across New York City neighborhoods. Females hospitalized with CA-MRSA had more than twice the odds of residing in neighborhoods in the highest quintile of HIV prevalence (adjusted odds ratio [AOR](Q5 vs. Q1) 2.3, 95% CI: 1.2, 2.7). Both males and females hospitalized with CA-MRSA had nearly twice the odds of residing in neighborhoods with moderately high proportion of men who have sex with men (MSM) residing in the neighborhood (males: AOR(Q4 vs. Q1) 1.7, 95% CI: 1.1, 2.7; females: AOR(Q4 vs. Q1) 2.0, 95% CI: 1.1, 3.6); but this association did not hold for neighborhoods in the highest quintile (males: AOR(Q5 vs. Q1) 1.2, 95% CI: 0.76, 1.8; females: AOR(Q5 vs. Q1) 1.5, 95% CI: 0.82, 2.7). Neighborhood-level characteristics were associated with CA-MRSA hospitalization odds, independent of individual-level risk factors, and may contribute to the population-level burden of CA-MRSA infection.

Tree mortality predicted from drought-induced vascular damage

Science.gov (United States)

Anderegg, William R.L.; Flint, Alan L.; Huang, Cho-ying; Flint, Lorraine E.; Berry, Joseph A.; Davis, Frank W.; Sperry, John S.; Field, Christopher B.

2015-01-01

The projected responses of forest ecosystems to warming and drying associated with twenty-first-century climate change vary widely from resiliency to widespread tree mortality1, 2, 3. Current vegetation models lack the ability to account for mortality of overstorey trees during extreme drought owing to uncertainties in mechanisms and thresholds causing mortality4, 5. Here we assess the causes of tree mortality, using field measurements of branch hydraulic conductivity during ongoing mortality in Populus tremuloides in the southwestern United States and a detailed plant hydraulics model. We identify a lethal plant water stress threshold that corresponds with a loss of vascular transport capacity from air entry into the xylem. We then use this hydraulic-based threshold to simulate forest dieback during historical drought, and compare predictions against three independent mortality data sets. The hydraulic threshold predicted with 75% accuracy regional patterns of tree mortality as found in field plots and mortality maps derived from Landsat imagery. In a high-emissions scenario, climate models project that drought stress will exceed the observed mortality threshold in the southwestern United States by the 2050s. Our approach provides a powerful and tractable way of incorporating tree mortality into vegetation models to resolve uncertainty over the fate of forest ecosystems in a changing climate.

Trees in urban street canyons and their impact on the dispersion of automobile exhausts

NARCIS (Netherlands)

Gromke, C.B.; Ruck, B.

2007-01-01

The aim of the present study is to clarify the influence of trees on the dispersion of automobile exhausts in urban street canyons. For this purpose, measurements have been performed with a small scale wind tunnel model of an idealized, isolated street canyon with model trees placed along the canyon

Effects of trees on the dilution of vehicle exhaust emissions in urban street canyons

NARCIS (Netherlands)

Gromke, C.B.; Ruck, B.

2009-01-01

In order to investigate the natural ventilation and air quality of urban street canyons with trees, boundary layer wind tunnel studies at a small-scale model have been performed. Concentrations in street canyons with a tracer gas emitting line source at the ground level and one row of trees arranged

Programmatic Impact of 5 Years of Mortality Surveillance of New York City Homeless Populations

Science.gov (United States)

Marder, Dova; Begier, Elizabeth; Gutkovich, Alexander; Mos, Robert; Griffin, Angela; Zimmerman, Regina; Madsen, Ann

2013-01-01

A homeless mortality surveillance system identifies emerging trends in the health of the homeless population and provides this information to key stakeholders in a timely and ongoing manner to effect evidence-based, programmatic change. We describe the first 5 years of the New York City homeless mortality surveillance system and, for the first time in peer-reviewed literature, illustrate the impact of key elements of sustained surveillance (i.e., timely dissemination of aggregate mortality data and real-time sharing of information on individual homeless decedents) on the programs of New York City’s Department of Homeless Services. These key elements had a positive impact on the department’s programs that target sleep-related infant deaths and hypothermia, drug overdose, and alcohol-related deaths among homeless persons. PMID:24148068

Atmospheric pollution and plants, especially trees in cities

International Nuclear Information System (INIS)

Pauly, T.; Lohou, C.

1992-01-01

Trees in down live in ecologically difficult conditions and suffer a great number of aggressions. Air pollution only increases their state of weakness. Studies in this field are only at their infancy. The part of responsibility of air pollution on the decay of trees is very difficult to determine. However the effect of some pollutants can be observed at present (sulfur dioxide, ozone, hydrocarburants, dust, PAN, lead...). New special equipment will determine, quantify and perhaps resolve some problems of pollution and vegetation in our cities in the future. 11 refs

Analysis of local scale tree-atmosphere interaction on pollutant concentration in idealized street canyons and application to a real urban junction

Science.gov (United States)

Buccolieri, Riccardo; Salim, Salim Mohamed; Leo, Laura Sandra; Di Sabatino, Silvana; Chan, Andrew; Ielpo, Pierina; de Gennaro, Gianluigi; Gromke, Christof

2011-03-01

This paper first discusses the aerodynamic effects of trees on local scale flow and pollutant concentration in idealized street canyon configurations by means of laboratory experiments and Computational Fluid Dynamics (CFD). These analyses are then used as a reference modelling study for the extension a the neighbourhood scale by investigating a real urban junction of a medium size city in southern Italy. A comparison with previous investigations shows that street-level concentrations crucially depend on the wind direction and street canyon aspect ratio W/H (with W and H the width and the height of buildings, respectively) rather than on tree crown porosity and stand density. It is usually assumed in the literature that larger concentrations are associated with perpendicular approaching wind. In this study, we demonstrate that while for tree-free street canyons under inclined wind directions the larger the aspect ratio the lower the street-level concentration, in presence of trees the expected reduction of street-level concentration with aspect ratio is less pronounced. Observations made for the idealized street canyons are re-interpreted in real case scenario focusing on the neighbourhood scale in proximity of a complex urban junction formed by street canyons of similar aspect ratios as those investigated in the laboratory. The aim is to show the combined influence of building morphology and vegetation on flow and dispersion and to assess the effect of vegetation on local concentration levels. To this aim, CFD simulations for two typical winter/spring days show that trees contribute to alter the local flow and act to trap pollutants. This preliminary study indicates that failing to account for the presence of vegetation, as typically practiced in most operational dispersion models, would result in non-negligible errors in the predictions.

Climate, Tree Growth, Forest Drought Stress, and Tree Mortality in Forests of Western North America: Long-Term Patterns and Recent Trends

Science.gov (United States)

Allen, C. D.; Williams, P.

2012-12-01

, Pinus ponderosa, and Pseudotsuga menziesii) in this region. FDSI responds sensitively and nonlinearly to growing season daily maximum temperatures which increase vapor pressure deficit, resulting in greater tree physiological stress and reduced tree growth. Drought conditions and warming temperatures in the Southwest since ca. 1996 have caused FDSI values in particular years since 2000 to start to exceed the most extreme values reconstructed from tree-rings for the past 1000 years for this region. FDSI demonstrates strong correlations with the spatial extent of major forest disturbances in the Southwest, including high-severity wildfire and bark beetle infestations, which over the past 20 years also have affected historically unprecedented levels. Similar trends of increasing extent and severity of forest disturbances are apparent across large portions of western North America. For the Southwest US, given relatively robust projections of substantial further increases in warmer temperatures and drought stress in coming decades, by ~2050 projected levels of FDSI and associated disturbances would reach extreme values, suggesting that current forest ecosystems likely would be forced to reorganize through wholesale tree mortality and the establishment of new dominant species.

Spatial aspects of tree mortality strongly differ between young and old-growth forests.

Science.gov (United States)

Larson, Andrew J; Lutz, James A; Donato, Daniel C; Freund, James A; Swanson, Mark E; HilleRisLambers, Janneke; Sprugel, Douglas G; Franklin, Jerry F

2015-11-01

Rates and spatial patterns of tree mortality are predicted to change during forest structural development. In young forests, mortality should be primarily density dependent due to competition for light, leading to an increasingly spatially uniform pattern of surviving trees. In contrast, mortality in old-growth forests should be primarily caused by contagious and spatially autocorrelated agents (e.g., insects, wind), causing spatial aggregation of surviving trees to increase through time. We tested these predictions by contrasting a three-decade record of tree mortality from replicated mapped permanent plots located in young (old) and old-growth (> 300-year-old) Abies amabilis forests. Trees in young forests died at a rate of 4.42% per year, whereas trees in old-growth forests died at 0.60% per year. Tree mortality in young forests was significantly aggregated, strongly density dependent, and caused live tree patterns to become more uniform through time. Mortality in old-growth forests was spatially aggregated, but was density independent and did not change the spatial pattern of surviving trees. These results extend current theory by demonstrating that density-dependent competitive mortality leading to increasingly uniform tree spacing in young forests ultimately transitions late in succession to a more diverse tree mortality regime that maintains spatial heterogeneity through time.

Widespread increase of tree mortality rates in the Western United States

Science.gov (United States)

van Mantgem, P.J.; Stephenson, N.L.; Byrne, J.C.; Daniels, L.D.; Franklin, J.F.; Fule, P.Z.; Harmon, M.E.; Larson, A.J.; Smith, Joseph M.; Taylor, A.H.; Veblen, T.T.

2009-01-01

Persistent changes in tree mortality rates can alter forest structure, composition, and ecosystem services such as carbon sequestration. Our analyses of longitudinal data from unmanaged old forests in the western United States showed that background (noncatastrophic) mortality rates have increased rapidly in recent decades, with doubling periods ranging from 17 to 29 years among regions. Increases were also pervasive across elevations, tree sizes, dominant genera, and past fire histories. Forest density and basal area declined slightly, which suggests that increasing mortality was not caused by endogenous increases in competition. Because mortality increased in small trees, the overall increase in mortality rates cannot be attributed solely to aging of large trees. Regional warming and consequent increases in water deficits are likely contributors to the increases in tree mortality rates.

A CFD study on the effectiveness of trees to disperse road traffic emissions at a city scale

Science.gov (United States)

Jeanjean, A. P. R.; Hinchliffe, G.; McMullan, W. A.; Monks, P. S.; Leigh, R. J.

2015-11-01

This paper focuses on the effectiveness of trees at dispersing road traffic emissions on a city scale. CFD simulations of air-pollutant concentrations were performed using the OpenFOAM software platform using the k-ε model. Results were validated against the CODASC wind tunnel database before being applied to a LIDAR database of buildings and trees representing the City of Leicester (UK). Most other CFD models in the literature typically use idealised buildings to model wind flow and pollution dispersion. However, the methodology used in this study uses real buildings and trees data from LIDAR to reconstruct a 3D representation of Leicester City Centre. It focuses on a 2 × 2 km area which is on a scale larger than those usually used in other CFD studies. Furthermore, the primary focus of this study is on the interaction of trees with wind flow dynamics. It was found that in effect, trees have a regionally beneficial impact on road traffic emissions by increasing turbulence and reducing ambient concentrations of road traffic emissions by 7% at pedestrian height on average. This was an important result given that previous studies generally concluded that trees trapped pollution by obstructing wind flow in street canyons. Therefore, this study is novel both in its methodology and subsequent results, highlighting the importance of combining local and regional scale models for assessing the impact of trees in urban planning.

Science in the city: Urban trees, forests, and people

Science.gov (United States)

Kathleen L. Wolf

2016-01-01

The article, intended for professional and manager audiences, is an overview of current research in urban forestry. Topics include tree science, forest risks, forest management and assessment, ecosystem services, and urban socio-ecological systems (including governance and stewardship).

Trees in Urban and City Environments: a review of the selection criteria with particular reference to nature conservation in New Zealand Cities

Directory of Open Access Journals (Sweden)

(Late David Given

2008-07-01

Full Text Available The overall aim of this research was to review the general criteria for selection of trees for urban environments and city environments. The reason for this research was to assess the extent to which criteria for tree selection can contribute to nature conservation in cities. We conducted an extensive review of the literature, looking for publications about the selection criteria. In particular, we looked for any previous published reviews of the criteria. With reference to the criteria used in New Zealand, we undertook an unstructured review of the practices adopted in most cities. A review of the literature revealed many publications about different criteria but only one publication in which there was a general review of the criteria used for selecting trees for urban environments. By way of contrast, lists of tree species deemed to be suitable (or unsuitable for urban planting are widely available, and some include information about selection criteria, but often with little background explanation. Worldwide, commonly used criteria included commercial availability of species, compatibility with urban environments, landscape design, low maintenance, avoidance of nuisance factors and historical practice. The most common criteria are concerned with the concept of choosing species compatible with local climate and soils. Anecdotal evidence suggests that more and more cities are using a mix of criteria including those that may contribute to conservation and restoration of native biota. We suggest that there should be greater use of ecological, genetic and biogeographical criteria to meet the needs of nature conservation in New Zealand cities.

Responses of gas-exchange rates and water relations to annual fluctuations of weather in three species of urban street trees.

Science.gov (United States)

Osone, Yoko; Kawarasaki, Satoko; Ishida, Atsushi; Kikuchi, Satoshi; Shimizu, Akari; Yazaki, Kenichi; Aikawa, Shin-Ichi; Yamaguchi, Masahiro; Izuta, Takeshi; Matsumoto, Genki I

2014-10-01

The frequency of extreme weather has been rising in recent years. A 3-year study of street trees was undertaken in Tokyo to determine whether: (i) street trees suffer from severe water stress in unusually hot summer; (ii) species respond differently to such climatic fluctuations; and (iii) street trees are also affected by nitrogen (N) deficiency, photoinhibition and aerosol pollution. During the study period (2010-12), midsummers of 2010 and 2012 were unusually hot (2.4-2.8 °C higher maximum temperature than the long-term mean) and dry (6-56% precipitation of the mean). In all species, street trees exhibited substantially decreased photosynthetic rate in the extremely hot summer in 2012 compared with the average summer in 2011. However, because of a more conservative stomatal regulation (stomatal closure at higher leaf water potential) in the hot summer, apparent symptoms of hydraulic failure were not observed in street trees even in 2012. Compared with Prunus × yedoensis and Zelkova serrata, Ginkgo biloba, a gymnosperm, was high in stomatal conductance and midday leaf water potential even under street conditions in the unusually hot summer, suggesting that the species had higher drought resistance than the other species and was less susceptible to urban street conditions. This lower susceptibility might be ascribed to the combination of higher soil-to-leaf hydraulic conductance and more conservative water use. Aside from meteorological conditions, N deficiency affected street trees significantly, whereas photoinhibition and aerosol pollution had little effect. The internal CO2 and δ(13)C suggested that both water and N limited the net photosynthetic rate of street trees simultaneously, but water was more limiting. From these results, we concluded that the potential risk of hydraulic failure caused by climatic extremes could be low in urban street trees in temperate regions. However, the size of the safety margin might be different between species. © The

Relationship of Climatic and Forest Factors to Drought- and Heat-Induced Tree Mortality.

Directory of Open Access Journals (Sweden)

Qingyin Zhang

Full Text Available Tree mortality due to warming and drought is a critical aspect of forest ecosystem in responding to climate change. Spatial patterns of tree mortality induced by drought and its influencing factors, however, have yet to be documented at the global scale. We collected observations from 248 sites globally where trees have died due to drought and then assessed the effects of climatic and forest factors on the rate of tree mortality. The global mean annual mortality rate was 5.5%. The rate of tree mortality was significantly and negatively correlated with mean annual precipitation (P 2000 mm and was severe in regions with mean annual precipitation <1000 mm. Mortality rates varied amongst species. The global annual rate of mortality was much higher for gymnosperms (7.1% than angiosperms (4.8% but did not differ significantly between evergreen (6.2% and deciduous (6.1% species. Stand age and wood density affected the mortality rate. Saplings (4.6% had a higher mortality rate than mature trees (3.2%, and mortality rates significantly decreased with increasing wood density for all species (P < 0.01. We therefore concluded that the tree mortality around the globe varied with climatic and forest factors. The differences between tree species, wood density, stand density, and stand age should be considered when evaluating tree mortality at a large spatial scale during future climatic extremes.

Are trees long-lived?

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Kevin T. Smith

2009-01-01

Trees and tree care can capture the best of people's motivations and intentions. Trees are living memorials that help communities heal at sites of national tragedy, such as Oklahoma City and the World Trade Center. We mark the places of important historical events by the trees that grew nearby even if the original tree, such as the Charter Oak in Connecticut or...

Research frontiers for improving our understanding of drought‐induced tree and forest mortality

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Hartmann, Henrik; Moura, Catarina; Anderegg, William R. L.; Ruehr, Nadine; Salmon, Yann; Allen, Craig D.; Arndt, Stefan K.; Breshears, David D.; Davi, Hendrik; Galbraith, David; Ruthrof, Katinka X.; Wunder, Jan; Adams, Henry D.; Bloemen, Jasper; Cailleret, Maxime; Cobb, Richard; Gessler, Arthur; Grams, Thorsten E. E.; Jansen, Steven; Kautz, Markus; Lloret, Francisco; O’Brien, Michael

2018-01-01

Accumulating evidence highlights increased mortality risks for trees during severe drought, particularly under warmer temperatures and increasing vapour pressure deficit (VPD). Resulting forest die‐off events have severe consequences for ecosystem services, biophysical and biogeochemical land–atmosphere processes. Despite advances in monitoring, modelling and experimental studies of the causes and consequences of tree death from individual tree to ecosystem and global scale, a general mechanistic understanding and realistic predictions of drought mortality under future climate conditions are still lacking. We update a global tree mortality map and present a roadmap to a more holistic understanding of forest mortality across scales. We highlight priority research frontiers that promote: (1) new avenues for research on key tree ecophysiological responses to drought; (2) scaling from the tree/plot level to the ecosystem and region; (3) improvements of mortality risk predictions based on both empirical and mechanistic insights; and (4) a global monitoring network of forest mortality. In light of recent and anticipated large forest die‐off events such a research agenda is timely and needed to achieve scientific understanding for realistic predictions of drought‐induced tree mortality. The implementation of a sustainable network will require support by stakeholders and political authorities at the international level.

Landscaping and landscape ecology in the management of tree plantation. A reference to the city of Medellin, Colombia

International Nuclear Information System (INIS)

Velez Restrepo, Luis Anibal

2007-01-01

The paper constitutes a reflection around the urban landscape, whit reference to Medellin, likewise around the landscaping and ecological potential that the city has along its terrain, its empty lots, without urbanizing, and especially, thanks to the tree plantation that its streets display. It is questioned the absence of a landscaping dimension in the urban planning; the increasing deterioration of the panoramic qualities; and the gradual loss of green spaces. At the same time, it is emphasized the importance that such tree planting has in the landscape, from the visual, social and environmental point of view. The work discusses the tendency to the artificiality of tree planting on sidewalks and vial road separators, raising conceptual limitations associated to the scale tree to tree, to the lack of incorporation of ecological landscape relations related to its handling, and to the landscaping approach within the framework of the urban designing. The reflection leans on data of the concrete situation, suggesting the complementary role that the vegetation could accomplish in streets and avenues with a perspective of ecological connectivity of the landscape

Mechanisms of piñon pine mortality after severe drought: a retrospective study of mature trees.

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Gaylord, Monica L; Kolb, Thomas E; McDowell, Nate G

2015-08-01

Conifers have incurred high mortality during recent global-change-type drought(s) in the western USA. Mechanisms of drought-related tree mortality need to be resolved to support predictions of the impacts of future increases in aridity on vegetation. Hydraulic failure, carbon starvation and lethal biotic agents are three potentially interrelated mechanisms of tree mortality during drought. Our study compared a suite of measurements related to these mechanisms between 49 mature piñon pine (Pinus edulis Engelm.) trees that survived severe drought in 2002 (live trees) and 49 trees that died during the drought (dead trees) over three sites in Arizona and New Mexico. Results were consistent over all sites indicating common mortality mechanisms over a wide region rather than site-specific mechanisms. We found evidence for an interactive role of hydraulic failure, carbon starvation and biotic agents in tree death. For the decade prior to the mortality event, dead trees had twofold greater sapwood cavitation based on frequency of aspirated tracheid pits observed with scanning electron microscopy (SEM), smaller inter-tracheid pit diameter measured by SEM, greater diffusional constraints to photosynthesis based on higher wood δ(13)C, smaller xylem resin ducts, lower radial growth and more bark beetle (Coleoptera: Curculionidae) attacks than live trees. Results suggest that sapwood cavitation, low carbon assimilation and low resin defense predispose piñon pine trees to bark beetle attacks and mortality during severe drought. Our novel approach is an important step forward to yield new insights into how trees die via retrospective analysis. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radiosensitivity and recovery of tree crowns in a gamma-irradiated northern forest community

International Nuclear Information System (INIS)

Buech, R.R.

1977-01-01

Crown mortality was observed on 13 tree species in a gamma-irradiated forest community located near Rhinelander, Wis. Observations at the end of the first (1973) and second (1974) postirradiation growing seasons are presented for each species. Crown mortality was most severe during 1973 for Acer rubrum, A. saccharum, Ostrya virginiana, Populus tremuloides, Prunus serotina, Quercus rubra, and Ulmus americana. For some species, however, crown mortality was most severe during 1974. These were Betula alleghaniensis, B. papyrifera, Tilia americana, and possibly Fraxinus americana and F. nigra. These differences in year of primary response are explained on the basis of bud differentiation and mortality. The most resistant species were A. saccharum, O. virginiana, and Populus tremuloides, and the most sensitive were T. americana and U. americana. Others were intermediate in sensitivity. Taken collectively, exposures less than 2 or 3 kr did not seriously affect crowns of most species, whereas exposures exceeding about 40 kr were lethal to the crowns of all tree species. The observed zonation of tree mortality closely approximated predictions published by others except for underestimating the resistance of A. saccharum and overestimating the resistance of T. americana, F. americana, and Prunus serotina. Not surprisingly, the tree stratum of the northern forest community was found to be more radiosensitive than lichen, grassland, or herbaceous communities in other irradiation studies

School-Based Budgeting in New York City: Perceptions of School Communities.

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Iatarola, Patrice; Stiefel, Leanna

1998-01-01

Summarizes results of surveys and interviews of community members from 29 New York City schools involved in school-level budgeting during 1995-96. Analyzes respondents' knowledge about school budgets, ideas about resource decision making, perceptions of budgetary power, and suggestions. Fully 80% of respondents supported a participatory process.…

Basin-Wide Amazon Forest Tree Mortality From a Large 2005 Storm

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Negron Juarez, R. I.; Chambers, J. Q.; Guimaraes, G.; Zeng, H.; Raupp, C.; Marra, D. M.; Ribeiro, G.; Saatchi, S. S.; Higuchi, N.

2010-12-01

Blowdowns are a recurrent characteristic of Amazon forests and are produced, among others, by squall lines. Squall lines are aligned clusters (typical length of 1000 km, width of 200 km) of deep convective cells that produce heavy rainfall during the dry season and significant rainfall during the wet season. These squall lines (accompanied by intense downbursts from convective cells) have been associated with large blowdowns characterized by uprooted, snapped trees, and trees being dragged down by other falling trees. Most squall lines in Amazonia form along the northeastern coast of South America as sea breeze-induced instability lines and propagate inside the continent. They occur frequently (~4 times per month), and can reach the central and even extreme western parts of Amazonia. Squall lines can also be generated inside the Amazon and propagate toward the equator. In January 2005 a squall line propagated from south to north across the entire Amazon basin producing widespread forest tree mortality and contributed to the elevated mortality observed that year. Over the Manaus region (3.4 x104 km2), disturbed forest patches generated by the squall produced a mortality of 0.3-0.5 million trees, equivalent to 30% of the observed annual deforestation reported in 2005 over the same area. The elevated mortality observed in the Central Amazon in 2005 is unlikely to be related to the 2005 Amazon drought since drought did not affect Central or Eastern Amazonia. Assuming a similar rate of forest mortality across the basin, the squall line could have potentially produced tree mortality estimated at 542 ± 121 million trees, equivalent to 23% of the mean annual biomass accumulation estimated for these forests. Our results highlight the vulnerability of Amazon trees to wind-driven mortality associated with convective storms. This vulnerability is likely to increase in a warming climate with models projecting an increase in storm intensity.

Stable Ca Isotopes in Tamarix aphylla Tree Rings, Death Valley, California

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Yang, W.; Depaolo, D. J.; Ingram, B. L.; Owens, T. L.

2008-12-01

As a dune stabilizer and windbreak, Tamarix aphylla is an exotic perennial and evergreen tree in Death Valley. Its tap roots can reach down to 30 m depth and sub-superficial side roots may reach 50 m horizontally. The species can store large amounts of water in its roots and undergoes high evapotranspiration. Since Tamarix aphylla is a perennial tree growing in desert environments and its roots reach deep to the water table, it could be a proxy for desert ecological and hydrologic systems through time. We measured Ca isotopes in the soluble fraction of 8 tree ring samples from a 50-year-old specimen growing on an alluvial fan in Death Valley near Furnace Creek. Previous studies (Yang et al, GCA 60, 1996) indicate that this tree's rings contain high sulfur concentrations (4-6% expressed as sulfate) with chemical composition of CaSO4 (0.15-0.62 H2O). The δ34S values of soluble sulfate increase from +13.5 to +18 permil VCDT from the core to the bark, which are interpreted as reflecting deeper sulfate sources as the tree grew. The δ13C variations of the tree-ring cellulose (-27.6 to -24.0 permil VPDB) reflect changes in the local precipitation and show that Tamarix aphylla undergoes C3 photosynthesis. The δ44Ca for the soluble sulfate Ca through the tree-ring section, which covers a time period from 1945 to 1993, have an average value -2.52 permil (-3.4 permil relative to seawater). Only small variations are observed, from -2.69 to -2.28; the highest value (for 1990) occurs near the end of an extended drought. These are the first measurements of tree rings, but the low δ44Ca values are consistent with previous measurements of beech roots and stems from a temperate forest (Page et al., Biogeochem. 88, 2008). In our case, the tree has only one Ca source, which is expected to be isotopically uniform and similar to both local rainfall and limestones (δ44Ca ~ -0.6 permil), and with the minimal vegetation and extensive deep root system it is unlikely that there is a

The Prediction of Drought-Related Tree Mortality in Vegetation Models

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Schwinning, S.; Jensen, J.; Lomas, M. R.; Schwartz, B.; Woodward, F. I.

2013-12-01

Drought-related tree die-off events at regional scales have been reported from all wooded continents and it has been suggested that their frequency may be increasing. The prediction of these drought-related die-off events from regional to global scales has been recognized as a critical need for the conservation of forest resources and improving the prediction of climate-vegetation interactions. However, there is no conceptual consensus on how to best approach the quantitative prediction of tree mortality. Current models use a variety of mechanisms to represent demographic events. Mortality is modeled to represent a number of different processes, including death by fire, wind throw, extreme temperatures, and self-thinning, and each vegetation model differs in the emphasis they place on specific mechanisms. Dynamic global vegetation models generally operate on the assumption of incremental vegetation shift due to changes in the carbon economy of plant functional types and proportional effects on recruitment, growth, competition and mortality, but this may not capture sudden and sweeping tree death caused by extreme weather conditions. We tested several different approaches to predicting tree mortality within the framework of the Sheffield Dynamic Global Vegetation Model. We applied the model to the state of Texas, USA, which in 2011 experienced extreme drought conditions, causing the death of an estimated 300 million trees statewide. We then compared predicted to actual mortality to determine which algorithms most accurately predicted geographical variation in tree mortality. We discuss implications regarding the ongoing debate on the causes of tree death.

Seeing the forest for the trees: hybridity and social-ecological symbols, rituals and resilience in postdisaster contexts

Directory of Open Access Journals (Sweden)

Keith G. Tidball

2014-12-01

Full Text Available The role of community-based natural resources management in the form of "greening" after large scale system shocks and surprises is argued to provide multiple benefits via engagement with living elements of social-ecological systems and subsequent enhanced resilience at multiple scales. The importance of so-called social-ecological symbols, especially the potent hybrid symbols of trees and their handling after a disaster is interrogated. The paper explores the notion of hybridity, and applies it to the hybrid symbol of the tree in postdisaster contexts. The paper briefly highlights three U.S. cases documenting the symbolic roles of trees in a context of significant shock to a social-ecological system: the terrorist attacks on New York City in 2001, the devastating hurricane that struck New Orleans in 2005, and the sudden tornadoes that wreaked havoc upon the small Midwestern city of Joplin, Missouri in 2011.

Does tree planting pay us back? Lessons from Sacramento, CA

Science.gov (United States)

Yekang Ko; Lara A. Roman; E. Gregory McPherson; Junhak. Lee

2016-01-01

The past decade could be called a renaissance of urban forestry, driven by mayoral tree planting initiatives and increased attention on city trees as green infrastructure. The political support for urban greening has been fueled by research that quantifies and projects the ecosystem services of planting initiatives (Young and McPherson 2013). Major cities have been...

Modelling diameter growth, mortality and recruitment of trees in ...

African Journals Online (AJOL)

Modelling diameter growth, mortality and recruitment of trees in miombo woodlands of Tanzania. ... Individual tree diameter growth and mortality models, and area-based recruitment models were developed. ... AJOL African Journals Online.

Numerical modeling of flow and pollutant dispersion in street canyons with tree planting

Energy Technology Data Exchange (ETDEWEB)

Balczo, Marton [Budapest Univ. of Technology and Economics (Hungary). Theodore von Karman Wind Tunnel Lab.; Gromke, Christof; Ruck, Bodo [Karlsruhe Univ. (Germany). Lab. of Building- and Environmental Aerodynamics

2009-04-15

Numerical simulations of the impact of tree planting on airflow and traffic pollutant dispersion in urban street canyons have been performed using the commercial CFD (Computational Fluid Dynamics) code MISKAM. A {kappa}-{epsilon} turbulence model including additional terms for the treatment of vegetation, has been employed to close the Reynolds-averaged-Navier-Stokes (RANS) equations. The numerical results were compared to wind tunnel data. In the case of the investigated wind direction perpendicular to the street axis, the presence of trees lead to increased pollutant concentrations inside the canyon. Concentrations increased strongly on the upstream side of the canyon, while on the downstream side a small concentration decrease could be observed. Lower flow velocities and higher pollutant concentrations were found in the numerical simulations when directly compared to the experimental results. However, the impact of tree planting on airflow and concentration fields when compared to the treeless street canyon as a reference configuration were simulated quite well, meaning that relative changes were similar in the wind tunnel investigations and numerical computations. This feature qualifies MISKAM for use as a tool for assessing the impacts of vegetation on local air quality. (orig.)

A Large Community Outbreak of Legionnaires' Disease Associated With a Cooling Tower in New York City, 2015.

Science.gov (United States)

Weiss, Don; Boyd, Christopher; Rakeman, Jennifer L; Greene, Sharon K; Fitzhenry, Robert; McProud, Trevor; Musser, Kimberlee; Huang, Li; Kornblum, John; Nazarian, Elizabeth J; Fine, Annie D; Braunstein, Sarah L; Kass, Daniel; Landman, Keren; Lapierre, Pascal; Hughes, Scott; Tran, Anthony; Taylor, Jill; Baker, Deborah; Jones, Lucretia; Kornstein, Laura; Liu, Boning; Perez, Rodolfo; Lucero, David E; Peterson, Eric; Benowitz, Isaac; Lee, Kristen F; Ngai, Stephanie; Stripling, Mitch; Varma, Jay K

Infections caused by Legionella are the leading cause of waterborne disease outbreaks in the United States. We investigated a large outbreak of Legionnaires' disease in New York City in summer 2015 to characterize patients, risk factors for mortality, and environmental exposures. We defined cases as patients with pneumonia and laboratory evidence of Legionella infection from July 2 through August 3, 2015, and with a history of residing in or visiting 1 of several South Bronx neighborhoods of New York City. We describe the epidemiologic, environmental, and laboratory investigation that identified the source of the outbreak. We identified 138 patients with outbreak-related Legionnaires' disease, 16 of whom died. The median age of patients was 55. A total of 107 patients had a chronic health condition, including 43 with diabetes, 40 with alcoholism, and 24 with HIV infection. We tested 55 cooling towers for Legionella, and 2 had a strain indistinguishable by pulsed-field gel electrophoresis from 26 patient isolates. Whole-genome sequencing and epidemiologic evidence implicated 1 cooling tower as the source of the outbreak. A large outbreak of Legionnaires' disease caused by a cooling tower occurred in a medically vulnerable community. The outbreak prompted enactment of a new city law on the operation and maintenance of cooling towers. Ongoing surveillance and evaluation of cooling tower process controls will determine if the new law reduces the incidence of Legionnaires' disease in New York City.

A Large Community Outbreak of Legionnaires’ Disease Associated With a Cooling Tower in New York City, 2015

Science.gov (United States)

Boyd, Christopher; Rakeman, Jennifer L.; Greene, Sharon K.; Fitzhenry, Robert; McProud, Trevor; Musser, Kimberlee; Huang, Li; Kornblum, John; Nazarian, Elizabeth J.; Fine, Annie D.; Braunstein, Sarah L.; Kass, Daniel; Landman, Keren; Lapierre, Pascal; Hughes, Scott; Tran, Anthony; Taylor, Jill; Baker, Deborah; Jones, Lucretia; Kornstein, Laura; Liu, Boning; Perez, Rodolfo; Lucero, David E.; Peterson, Eric; Benowitz, Isaac; Lee, Kristen F.; Ngai, Stephanie; Stripling, Mitch; Varma, Jay K.

2017-01-01

Objectives: Infections caused by Legionella are the leading cause of waterborne disease outbreaks in the United States. We investigated a large outbreak of Legionnaires’ disease in New York City in summer 2015 to characterize patients, risk factors for mortality, and environmental exposures. Methods: We defined cases as patients with pneumonia and laboratory evidence of Legionella infection from July 2 through August 3, 2015, and with a history of residing in or visiting 1 of several South Bronx neighborhoods of New York City. We describe the epidemiologic, environmental, and laboratory investigation that identified the source of the outbreak. Results: We identified 138 patients with outbreak-related Legionnaires’ disease, 16 of whom died. The median age of patients was 55. A total of 107 patients had a chronic health condition, including 43 with diabetes, 40 with alcoholism, and 24 with HIV infection. We tested 55 cooling towers for Legionella, and 2 had a strain indistinguishable by pulsed-field gel electrophoresis from 26 patient isolates. Whole-genome sequencing and epidemiologic evidence implicated 1 cooling tower as the source of the outbreak. Conclusions: A large outbreak of Legionnaires’ disease caused by a cooling tower occurred in a medically vulnerable community. The outbreak prompted enactment of a new city law on the operation and maintenance of cooling towers. Ongoing surveillance and evaluation of cooling tower process controls will determine if the new law reduces the incidence of Legionnaires’ disease in New York City. PMID:28141970

Assessment and classification of hazardous street trees in University ...

African Journals Online (AJOL)

The study was carried out to assessed and classified hazardous trees within the University of Ibadan (UI) campus, Oyo State, Nigeria. The study population was 25 municipal tree species comprising of 420 individual trees located along the major roads of the study area, which were considered hazardous to the community.

City of Berkeley, California Municipal Tree Resource Analysis

Science.gov (United States)

S.E. Maco; E.G. McPherson; J.R. Simpson; P.J. Peper; Q. Xiao

2005-01-01

Vibrant, renowned for its livability and cultural wealth, the city of Berkeley maintains trees as an integral component of the urban infrastructure. Research indicates that healthy trees can mitigate impacts associated with the built environment by reducing stormwater runoff, energy consumption, and air pollutants. Put simply, trees improve urban life, making Berkeley...

City of Boulder, Colorado Municipal Tree Resource Analysis

Science.gov (United States)

E.G. McPherson; J.R. Simpson; P.J. Peper; S.L. Gardner; K.E. Vargas; Q. Xiao

2005-01-01

Boulder is a vibrant city, renowned for its livability and cultural wealth and well known for its Smart Growth policies that protect and restore environmental quality while enhancing economic opportunity. The city maintains trees as an integral component of the urban infrastructure. Research indicates that healthy trees can mitigate impacts associated with the built...

Drought-related tree mortality in drought-resistant semi-arid Aleppo pine forest

Science.gov (United States)

Preisler, Yakir; Grünzweig, José M.; Rotenberg, Eyal; Rohatyn, Shani; Yakir, Dan

2014-05-01

The frequency and intensity of drought events are expected to increase as part of global climate change. In fact, drought related tree mortality had become a widespread phenomenon in forests around the globe in the past decades. This study was conducted at the Yatir FLUXNET site, located in a 45 years old Pinus halepensis dominated forest that successfully sustained low mean annual precipitation (276mm) and extended seasonal droughts (up to 340 days between rain events). However, five recent non-consecutive drought years led to enhanced tree mortality in 2010 (5-10% of the forest population, which was not observed hitherto). The Tree mortality was characterized by patchiness, showing forest zones with either >80% mortality or no mortality at all. Areas of healthy trees were associated with deeper root distribution and increased stoniness (soil pockets & cracks). To help identify possible causes of the increased mortality and its patterns, four tree stress levels were identified based on visual appearance, and studied in more detail. This included examining from spring 2011 to summer 2013 the local trees density, root distribution, annual growth rings, needle length and chlorophyll content, rates of leaf gas exchange, and branch predawn water potential. Tree phenotypic stress level correlated with the leaf predawn water potential (-1.8 and -3.0 in healthy and stressed trees, respectively), which likely reflected tree-scale water availability. These below ground characteristics were also associated, in turn, with higher rate of assimilation (3.5 and 0.8 μmol CO2 m-2s1 in healthy and stress trees, respectively), longer needles (8.2cm and 3.4 cm in healthy and stressed trees, respectively). Annual ring widths showed differences between stress classes, with stressed trees showing 30% narrower rings on average than unstressed trees. Notably, decline in annual ring widths could be identified in currently dead or severely stressed trees 15-20 years prior to mortality or

Impact of trees on pollutant dispersion in street canyons: A numerical study of the annual average effects in Antwerp, Belgium.

Science.gov (United States)

Vranckx, Stijn; Vos, Peter; Maiheu, Bino; Janssen, Stijn

2015-11-01

Effects of vegetation on pollutant dispersion receive increased attention in attempts to reduce air pollutant concentration levels in the urban environment. In this study, we examine the influence of vegetation on the concentrations of traffic pollutants in urban street canyons using numerical simulations with the CFD code OpenFOAM. This CFD approach is validated against literature wind tunnel data of traffic pollutant dispersion in street canyons. The impact of trees is simulated for a variety of vegetation types and the full range of approaching wind directions at 15° interval. All these results are combined using meteo statistics, including effects of seasonal leaf loss, to determine the annual average effect of trees in street canyons. This analysis is performed for two pollutants, elemental carbon (EC) and PM10, using background concentrations and emission strengths for the city of Antwerp, Belgium. The results show that due to the presence of trees the annual average pollutant concentrations increase with about 8% (range of 1% to 13%) for EC and with about 1.4% (range of 0.2 to 2.6%) for PM10. The study indicates that this annual effect is considerably smaller than earlier estimates which are generally based on a specific set of governing conditions (1 wind direction, full leafed trees and peak hour traffic emissions). Copyright © 2015 Elsevier B.V. All rights reserved.

Trends and Tipping Points of Drought-induced Tree Mortality

Science.gov (United States)

Huang, K.; Yi, C.; Wu, D.; Zhou, T.; Zhao, X.; Blanford, W. J.; Wei, S.; Wu, H.; Du, L.

2014-12-01

Drought-induced tree mortality worldwide has been recently reported in a review of the literature by Allen et al. (2010). However, a quantitative relationship between widespread loss of forest from mortality and drought is still a key knowledge gap. Specifically, the field lacks quantitative knowledge of tipping point in trees when coping with water stress, which inhibits the assessments of how climate change affects the forest ecosystem. We investigate the statistical relationships for different (seven) conifer species between Ring Width Index (RWI) and Standardized Precipitation Evapotranspiration Index (SPEI), based on 411 chronologies from the International Tree-Ring Data Bank across 11 states of the western United States. We found robust species-specific relationships between RWI and SPEI for all seven conifer species at dry condition. The regression models show that the RWI decreases with SPEI decreasing (drying) and more than 76% variation of tree growth (RWI) can be explained by the drought index (SPEI). However, when soil water is sufficient (i.e., SPEI>SPEIu), soil water is no longer a restrictive factor for tree growth and, therefore, the RWI shows a weak correlation with SPEI. Based on the statistical models, we derived the tipping point of SPEI (SPEItp) where the RWI equals 0, which means the carbon efflux by tree respiration equals carbon influx by tree photosynthesis. When the severity of drought exceeds this tipping point(i.e. SPEIsupported by the Fund for Creative Research Groups of National Natural Science Foundation of China (No. 41321001), the National Basic Research Program of China (No. 2012CB955401), the New Century Excellent Talents in University (No. NCET-10-0251), U.S. PSC-CUNY Award (PSC-CUNY-ENHC-44-83) and the High Technology Research and Development Program of China (No. 2013AA122801).

Meta-analysis Reveals that Hydraulic Traits Explain Cross-Species Patterns of Drought-Induced Tree Mortality across the Globe

Science.gov (United States)

Anderegg, W.

2016-12-01

Drought-induced tree mortality has been observed globally and is expected to increase under climate change scenarios, with large potential consequences for the terrestrial carbon sink. Predicting mortality across species is crucial for assessing the effects of climate extremes on forest community biodiversity, composition, and carbon sequestration. However, the physiological traits associated with elevated risk of mortality in diverse ecosystems remain unknown, though these could greatly improve understanding and prediction of tree mortality in forests. We performed a meta-analysis on species' mortality rates across 475 species from 33 studies around the globe to assess which traits determine a species' mortality risk. We found that species-specific mortality anomalies from community mortality rate in a given drought were associated with plant hydraulic traits. Across all species, mortality was best predicted by a low hydraulic safety margin - the difference between typical minimum xylem water potential and that causing xylem dysfunction - and xylem vulnerability to embolism. Angiosperms and gymnosperms experienced roughly equal mortality risk. Our results provide broad support that hydraulic traits capture key mechanisms determining tree death and highlight that physiological traits can improve vegetation models' prediction of tree mortality during climate extremes. We conclude with thoughts about a revised framework for future tree mortality research.

Growing Greener Cities: A Tree-Planting Handbook.

Science.gov (United States)

Moll, Gary; Young, Stanley

This step-by-step guide, developed by the Global ReLeaf organization, presents tree-planting advice and simple steps to organizing a successful community tree-planting and tree-care program. The text is divided into three parts. Part 1 introduces trees and discusses the role they play as components of the living urban environment. Distinctions are…

Carbon Impacts of Fire- and Bark Beetle-Caused Tree Mortality across the Western US using the Community Land Model (Invited)

Science.gov (United States)

Meddens, A. J.; Hicke, J. A.; Edburg, S. L.; Lawrence, D. M.

2013-12-01

Wildfires and bark beetle outbreaks cause major forest disturbances in the western US, affecting ecosystem productivity and thereby impacting forest carbon cycling and future climate. Despite the large spatial extent of tree mortality, quantifying carbon flux dynamics following fires and bark beetles over larger areas is challenging because of forest heterogeneity, varying disturbance severities, and field observation limitations. The objective of our study is to estimate these dynamics across the western US using the Community Land Model (version CLM4.5-BGC). CLM4.5-BGC is a land ecosystem model that mechanistically represents the exchanges of energy, water, carbon, and nitrogen with the atmosphere. The most recent iteration of the model has been expanded to include vertically resolved soil biogeochemistry and includes improved nitrogen cycle representations including nitrification and denitrification and biological fixation as well as improved canopy processes including photosynthesis. Prior to conducting simulations, we modified CLM4.5-BGC to include the effects of bark beetle-caused tree mortality on carbon and nitrogen stocks and fluxes. Once modified, we conducted paired simulations (with and without) fire- and bark beetle-caused tree mortality by using regional data sets of observed mortality as inputs. Bark beetle-caused tree mortality was prescribed from a data set derived from US Forest Service aerial surveys from 1997 to 2010. Annual tree mortality area was produced from observed tree mortality caused by bark beetles and was adjusted for underestimation. Fires were prescribed using the Monitoring Trends in Burn Severity (MTBS) database from 1984 to 2010. Annual tree mortality area was produced from forest cover maps and inclusion of moderate- and high-severity burned areas. Simulations show that maximum yearly reduction of net ecosystem productivity (NEP) caused by bark beetles is approximately 20 Tg C for the western US. Fires cause similar reductions

The impact of cigarette excise tax increases on purchasing behaviors among New York city smokers.

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Coady, Micaela H; Chan, Christina A; Sacks, Rachel; Mbamalu, Ijeoma G; Kansagra, Susan M

2013-06-01

We examined the relationship between cigarette excise tax increases and tax-avoidant purchasing behaviors among New York City adult smokers. We analyzed data from the city's annual Community Health Survey to assess changes in rates of tax avoidance over time (2003-2010) and smokers' responses to the 2008 state cigarette tax increase. Multivariable logistic regression analysis identified correlates of buying more cigarettes on the street in response to the increase. After the 2002 tax increase, the percentage of smokers engaged in tax-avoidant behavior decreased with time from 30% in 2003 to 13% in 2007. Following the 2008 tax increase, 21% of smokers reported buying more cigarettes from another person on the street. Low-income, younger, Black, and Hispanic smokers were more likely than respondents with other sociodemographic characteristics to purchase more cigarettes on the street. To maximize public health impact, cigarette tax increases should be paired with efforts to limit the flow of untaxed cigarettes entering jurisdictions with high cigarette pack prices.

Factors affecting long-term mortality of residential shade trees: evidence from Sacramento, California

Science.gov (United States)

Yekang Ko; Jun-Hak Lee; E. Gregory McPherson; Lara A. Roman

2015-01-01

Urban tree survival is essential to sustain the ecosystem services of urban forests and monitoring is needed to accurately assess benefits. While some urban forestry studies have reported street tree survival, little is known about the factors influencing residential yard tree survival, especially over the long-term. We assessed residential shade tree survival in...

Aerodynamic effects of trees on pollutant concentration in street canyons

NARCIS (Netherlands)

Buccolieri, R.; Gromke, C.B.; Sabatino, Di S.; Ruck, B.

2009-01-01

This paper deals with aerodynamic effects of avenue-like tree planting on flow and traffic-originated pollutant dispersion in urban street canyons by means of wind tunnel experiments and numerical simulations. Several parameters affecting pedestrian level concentration are investigated, namely plant

Homogenizing an urban habitat mosaic: arthropod diversity declines in New York City parks after Super Storm Sandy.

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Savage, Amy M; Youngsteadt, Elsa; Ernst, Andrew F; Powers, Shelby A; Dunn, Robert R; Frank, Steven D

2018-01-01

The frequency and intensity of hurricanes are increasing globally, and anthropogenic modifications in cities have created systems that may be particularly vulnerable to their negative effects. Organisms living in cities are exposed to variable levels of chronic environmental stress. However, whether chronic stress ameliorates or exacerbates the negative effects of hurricanes remains an open question. Here, we consider two hypotheses about the simultaneous consequences of acute disturbances from hurricanes and chronic stress from urbanization for the structure of urban arthropod communities. The tipping point hypothesis posits that organisms living in high stress habitats are less resilient than those in low stress habitats because they are living near the limits of their environmental tolerances; while the disturbance tolerance hypothesis posits that high stress habitats host organisms pre-adapted for coping with disturbance, making them more resilient to the effects of storms. We used a before-after-control-impact design in the street medians and city parks of Manhattan (New York City, New York, USA) to compare arthropod communities before and after Super Storm Sandy in sites that were flooded and unflooded during the storm. Our evidence supported the disturbance tolerance hypothesis. Significant compositional differences between street medians and city parks before the storm disappeared after the storm; similarly, unflooded city parks had significantly different arthropod composition while flooded sites were indistinguishable. These differences were driven by reduced occurrences and abundances of arthropods in city parks. Finally, those arthropod groups that were most tolerant to urban stress were also the most tolerant to flooding. Our results suggest that the species that survive in high stress environments are likely to be the ones that thrive in response to acute disturbance. As storms become increasingly common and extreme, this juxtaposition in responses to

Tree regeneration following drought- and insect-induced mortality in piñon-juniper woodlands.

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Redmond, Miranda D; Barger, Nichole N

2013-10-01

Widespread piñon (Pinus edulis) mortality occurred across the southwestern USA during 2002-2003 in response to drought and bark beetle infestations. Given the recent mortality and changes in regional climate over the past several decades, there is a keen interest in post-mortality regeneration dynamics in piñon-juniper woodlands. Here, we examined piñon and Utah juniper (Juniperus osteosperma) recruitment at 30 sites across southwestern Colorado, USA that spanned a gradient of adult piñon mortality levels (10-100%) to understand current regeneration dynamics. Piñon and juniper recruitment was greater at sites with more tree and shrub cover. Piñon recruitment was more strongly facilitated than juniper recruitment by trees and shrubs. New (post-mortality) piñon recruitment was negatively affected by recent mortality. However, mortality had no effect on piñon advanced regeneration (juveniles established pre-mortality) and did not shift juvenile piñon dominance. Our results highlight the importance of shrubs and juniper trees for the facilitation of piñon establishment and survival. Regardless of adult piñon mortality levels, areas with low tree and shrub cover may become increasingly juniper dominated as a result of the few suitable microsites for piñon establishment and survival. In areas with high piñon mortality and high tree and shrub cover, our results suggest that piñon is regenerating via advanced regeneration. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

On the impact of trees on dispersion processes of traffic emissions in street canyons

NARCIS (Netherlands)

Gromke, C.B.; Ruck, B.

2009-01-01

Wind-tunnel studies of dispersion processes of traffic exhaust in urban street canyons with tree planting were performed and tracer gas concentrations using electron capture detection (ECD) and flow fields using laser Doppler velocimetry (LDV) were measured. It was found that tree planting reduces

Climatic correlates of tree mortality in water- and energy-limited forests.

Directory of Open Access Journals (Sweden)

Adrian J Das

Full Text Available Recent increases in tree mortality rates across the western USA are correlated with increasing temperatures, but mechanisms remain unresolved. Specifically, increasing mortality could predominantly be a consequence of temperature-induced increases in either (1 drought stress, or (2 the effectiveness of tree-killing insects and pathogens. Using long-term data from California's Sierra Nevada mountain range, we found that in water-limited (low-elevation forests mortality was unambiguously best modeled by climatic water deficit, consistent with the first mechanism. In energy-limited (high-elevation forests deficit models were only equivocally better than temperature models, suggesting that the second mechanism is increasingly important in these forests. We could not distinguish between models predicting mortality using absolute versus relative changes in water deficit, and these two model types led to different forecasts of mortality vulnerability under future climate scenarios. Our results provide evidence for differing climatic controls of tree mortality in water- and energy-limited forests, while highlighting the need for an improved understanding of tree mortality processes.

Observations from old forests underestimate climate change effects on tree mortality.

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Luo, Yong; Chen, Han Y H

2013-01-01

Understanding climate change-associated tree mortality is central to linking climate change impacts and forest structure and function. However, whether temporal increases in tree mortality are attributed to climate change or stand developmental processes remains uncertain. Furthermore, interpreting the climate change-associated tree mortality estimated from old forests for regional forests rests on an un-tested assumption that the effects of climate change are the same for young and old forests. Here we disentangle the effects of climate change and stand developmental processes on tree mortality. We show that both climate change and forest development processes influence temporal mortality increases, climate change-associated increases are significantly higher in young than old forests, and higher increases in younger forests are a result of their higher sensitivity to regional warming and drought. We anticipate our analysis to be a starting point for more comprehensive examinations of how forest ecosystems might respond to climate change.

Overstory Tree Mortality in Ponderosa Pine and Spruce-Fir Ecosystems Following a Drought in Northern New Mexico

Directory of Open Access Journals (Sweden)

Brian P. Oswald

2016-10-01

Full Text Available Drought-caused tree dieback is an issue around the world as climates change and many areas become dryer and hotter. A drought from 1998–2004 resulted in a significant tree dieback event in many of the wooded areas in portions of the Jemez Mountains and the adjacent Pajarito Plateau in northern New Mexico. The objectives of this study were to evaluate and quantify the differences in tree mortality before and after a recent drought in ponderosa pine and spruce-fir ecosystems, and to assess the effect of mechanical thinning on ponderosa pine mortality. Significant increases in mortality were observed in the unthinned ponderosa pine ecosystem. Mortality varied significantly between species and within size classes. Mechanical thinning of ponderosa pines reduced overstory mortality to non-significant levels. A lack of rainfall, snowfall, and increases in daily minimum temperature contributed most to the mortality. Adaptive management, including the use of thinning activities, appear to moderate the impact of climate change on ponderosa pine forests in this region, increasing the long-term health of the ecosystem. The impact of climate change on the spruce-fir ecosystems may accelerate successional changes.

Assessment of Urban Infrastructure Impact on New York City Neighborhoods Thermal Variations

Science.gov (United States)

Nazari, R.; Ghandehari, M.; Karimi, M.; Vant-hull, B.; Khanbilvardi, R.

2013-12-01

New York City (NYC) is a highly urbanized city with most of the population living in tall buildings. Despite technological improvements and stricter regulations, cities still show increasing signs of environmental stress such as traffic congestion, noise and air quality degradation. Rethinking the current models of city planning could enable to limit these detrimental effects of urbanization. In addition, the built environment creates a new climatic regime which needs a better understanding. Building density, height and emission has a major impact on local temperature and other air quality indicators. Studies have shown that during extreme weather conditions and heat waves the mortality rate in urban areas increases. Cities are comprised of a wide variety of urban settings and various neighborhoods have different physical responses to meteorological events, so it is expected that the temperature and heat stress across a given city to fluctuate sharply. Therefore, this research has focused on neighborhood-scale field campaigns to downscale temperature and air quality predictions from city to neighborhood scale in NYC. In order to assess the temperature variability within the city at street level, during the hottest part of the day, this project used eight mobile units bearing temperature and relative humidity sensors, as well as ten weather stations mounted on light poles in various NYC neighborhoods. This study also looks at fine scale structures in the urban heat island of Manhattan at street level through an infrared camera with the spectral range of 7.5-13 μm in order to relate heat and emissions from building surfaces to land surface characteristics such as building density, vegetation coverage, proximity to water, and albedo. LandSat TM5 images were used (with 30 m resolution) for land surface classification. During the summer and early fall of 2011, 2012 and 2013 extensive field campaigns were performed, the results of which show some persistent patterns

Identification of New Diterpenes as Putative Marker Compounds Distinguishing Agnus Castus Fruit (Chaste Tree) from Shrub Chaste Tree Fruit (Viticis Fructus).

Science.gov (United States)

Oshima, Naohiro; Masada, Sayaka; Suzuki, Ryuta; Yagi, Kanae; Matsufuji, Hiroshi; Suenaga, Emi; Takahashi, Yutaka; Yahagi, Tadahiro; Watanabe, Masato; Yahara, Shoji; Iida, Osamu; Kawahara, Nobuo; Maruyama, Takuro; Goda, Yukihiro; Hakamatsuka, Takashi

2016-01-01

Agnus Castus Fruit is defined in the European Pharmacopoeia as the dried ripe fruit of Vitex agnus-castus. In Europe it is used as a medicine targeting premenstrual syndrome and climacteric disorder. In Japan, Agnus Castus Fruit is becoming popular as a raw material for over-the-counter drugs and health food products, though its congenic species, Vitex rotundifolia and Vitex trifolia, have been used as Shrub Chaste Tree Fruit in traditional medicines. Therefore, it is important to discriminate these Vitex plants from the viewpoint of regulatory science. Here we tried to identify putative marker compounds that distinguish between Agnus Castus Fruit and Shrub Chaste Tree Fruit. We analyzed extracts of each crude drug by liquid chromatography-mass spectrometry, and performed differential analysis by comparison of each chromatogram to find one or more peaks characteristic of Agnus Castus Fruit. A peak was isolated and identified as an equilibrium mixture of new compounds named chastol (1) and epichastol (1a). The planar structures of 1 and 1a were determined spectroscopically. Their relative configurations were revealed by nuclear Overhauser effect spectroscopy and differential nuclear Overhauser effect-NMR data. Since avoiding contamination from closely related species is needed for the quality control of natural pharmaceuticals, this information will be valuable to establish a method for the quality control of both, Agnus Castus Fruit and Shrub Chaste Tree Fruit products. Georg Thieme Verlag KG Stuttgart · New York.

Determinants of establishment survival for residential trees in Sacramento County, CA

Science.gov (United States)

Lara A. Roman; John J. Battles; Joe R. McBride

2014-01-01

Urban forests can provide ecosystem services that motivate tree planting campaigns, and tree survival is a key element of program success and projected benefits. We studied survival in a shade tree give-away program in Sacramento, CA, monitoring a cohort of young trees for five years on single-family residential properties. We used conditional inference trees to...

Forest Management Intensity Affects Aquatic Communities in Artificial Tree Holes.

Science.gov (United States)

Petermann, Jana S; Rohland, Anja; Sichardt, Nora; Lade, Peggy; Guidetti, Brenda; Weisser, Wolfgang W; Gossner, Martin M

2016-01-01

Forest management could potentially affect organisms in all forest habitats. However, aquatic communities in water-filled tree-holes may be especially sensitive because of small population sizes, the risk of drought and potential dispersal limitation. We set up artificial tree holes in forest stands subject to different management intensities in two regions in Germany and assessed the influence of local environmental properties (tree-hole opening type, tree diameter, water volume and water temperature) as well as regional drivers (forest management intensity, tree-hole density) on tree-hole insect communities (not considering other organisms such as nematodes or rotifers), detritus content, oxygen and nutrient concentrations. In addition, we compared data from artificial tree holes with data from natural tree holes in the same area to evaluate the methodological approach of using tree-hole analogues. We found that forest management had strong effects on communities in artificial tree holes in both regions and across the season. Abundance and species richness declined, community composition shifted and detritus content declined with increasing forest management intensity. Environmental variables, such as tree-hole density and tree diameter partly explained these changes. However, dispersal limitation, indicated by effects of tree-hole density, generally showed rather weak impacts on communities. Artificial tree holes had higher water temperatures (on average 2°C higher) and oxygen concentrations (on average 25% higher) than natural tree holes. The abundance of organisms was higher but species richness was lower in artificial tree holes. Community composition differed between artificial and natural tree holes. Negative management effects were detectable in both tree-hole systems, despite their abiotic and biotic differences. Our results indicate that forest management has substantial and pervasive effects on tree-hole communities and may alter their structure and

Environmental justice and factors that influence participation in tree planting programs in Portland, Oregon, U.S

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Geoffrey H. Donovan; John Mills

2014-01-01

Many cities have policies encouraging homeowners to plant trees. For these policies to be effective, it is important to understand what motivates a homeowner’s tree-planting decision. Researchers address this question by identifying variables that influence participation in a tree-planting program in Portland, Oregon, U.S. According to the study, homeowners with street...

Towards More Comprehensive Projections of Urban Heat-Related Mortality: Estimates for New York City Under Multiple Population, Adaptation, and Climate Scenarios

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Petkova, Elisaveta P.; Vink, Jan K.; Horton, Radley M.; Gasparrini, Antonio; Bader, Daniel A.; Francis, Joe D.; Kinney, Patrick L.

2016-01-01

High temperatures have substantial impacts on mortality and, with growing concerns about climate change, numerous studies have developed projections of future heat-related deaths around the world. Projections of temperature-related mortality are often limited by insufficient information necessary to formulate hypotheses about population sensitivity to high temperatures and future demographics. This study has derived projections of temperature-related mortality in New York City by taking into account future patterns of adaptation or demographic change, both of which can have profound influences on future health burdens. We adopt a novel approach to modeling heat adaptation by incorporating an analysis of the observed population response to heat in New York City over the course of eight decades. This approach projects heat-related mortality until the end of the 21st century based on observed trends in adaptation over a substantial portion of the 20th century. In addition, we incorporate a range of new scenarios for population change until the end of the 21st century. We then estimate future heat-related deaths in New York City by combining the changing temperature-mortality relationship and population scenarios with downscaled temperature projections from the 33 global climate models (GCMs) and two Representative Concentration Pathways (RCPs).The median number of projected annual heat-related deaths across the 33 GCMs varied greatly by RCP and adaptation and population change scenario, ranging from 167 to 3331 in the 2080s compared to 638 heat-related deaths annually between 2000 and 2006.These findings provide a more complete picture of the range of potential future heat-related mortality risks across the 21st century in New York, and highlight the importance of both demographic change and adaptation responses in modifying future risks.

Insect-induced tree mortality of boreal forests in eastern Canada under a changing climate.

Science.gov (United States)

Zhang, Xiongqing; Lei, Yuancai; Ma, Zhihai; Kneeshaw, Dan; Peng, Changhui

2014-06-01

Forest insects are major disturbances that induce tree mortality in eastern coniferous (or fir-spruce) forests in eastern North America. The spruce budworm (SBW) (Choristoneura fumiferana [Clemens]) is the most devastating insect causing tree mortality. However, the relative importance of insect-caused mortality versus tree mortality caused by other agents and how this relationship will change with climate change is not known. Based on permanent sample plots across eastern Canada, we combined a logistic model with a negative model to estimate tree mortality. The results showed that tree mortality increased mainly due to forest insects. The mean difference in annual tree mortality between plots disturbed by insects and those without insect disturbance was 0.0680 per year (P eastern Canada but that tree mortality induced by insect outbreaks will decrease in eastern Canada under warming climate.

Responses of Sap Flux Density to Changing Atmospheric Humidity in Three Common Street Tree Species in Bangkok, Thailand

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Pantana Tor-ngern

2016-09-01

Full Text Available Efficient water management in urban landscape is imperative under the projected increases in drought stress under future climate. Because different tree species have different stomatal regulations to prevent water loss under water limitation, comparative study of species-specific responses of water use to changing weather conditions will benefit selective planting of urban trees for sustainable urban greening management. Here, we performed a simple and short-term investigation of water use characteristics of three common street tree species in Bangkok, a major city in Southeast Asia. Species included Pterocarpus indicus (Pi, Swietenia macrophylla (Sm and Lagerstroemia speciosa (Ls. We used self-constructed heat dissipation probes to track water uptake rates, expressed as sap flux density (JS, in stems of potted trees and examined their diurnal variations with changing atmospheric humidity, represented by vapor pressure deficit (D. The results implied that two of the three species: Pi and Sm, may be selected for planting because their Js was less sensitive to changing D compared to Ls. The sap flux density of Ls increased more rapidly with rising D, implying higher sensitivity to drought in Ls, compared to the other two species. Nevertheless, further study on large trees and under longer period of investigation, covering both dry and wet seasons, is required to confirm this finding.

A technique for mapping urban ash trees using object-based image analysis

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Dacia M. Meneguzzo; Susan J. Crocker; Greg C. Liknes

2010-01-01

Ash trees are an important resource in the State of Minnesota and a common fixture lining the streets of the Twin Cities metropolitan area. In 2009, the emerald ash borer (EAB), an invasive pest of ash, was discovered in the city of St. Paul. To properly respond to the new-found threat, decisionmakers would benefit from detailed, spatially explicit information on the...

The hydrological vulnerability of western North American boreal tree species based on ground-based observations of tree mortality

Science.gov (United States)

Hember, R. A.; Kurz, W. A.; Coops, N. C.

2017-12-01

Several studies indicate that climate change has increased rates of tree mortality, adversely affecting timber supply and carbon storage in western North American boreal forests. Statistical models of tree mortality can play a complimentary role in detecting and diagnosing forest change. Yet, such models struggle to address real-world complexity, including expectations that hydrological vulnerability arises from both drought stress and excess-water stress, and that these effects vary by species, tree size, and competitive status. Here, we describe models that predict annual probability of tree mortality (Pm) of common boreal tree species based on tree height (H), biomass of larger trees (BLT), soil water content (W), reference evapotranspiration (E), and two-way interactions. We show that interactions among H and hydrological variables are consistently significant. Vulnerability to extreme droughts consistently increases as H approaches maximum observed values of each species, while some species additionally show increasing vulnerability at low H. Some species additionally show increasing vulnerability to low W under high BLT, or increasing drought vulnerability under low BLT. These results suggest that vulnerability of trees to increasingly severe droughts depends on the hydraulic efficiency, competitive status, and microclimate of individual trees. Static simulations of Pm across a 1-km grid (i.e., with time-independent inputs of H, BLT, and species composition) indicate complex spatial patterns in the time trends during 1965-2014 and a mean change in Pm of 42 %. Lastly, we discuss how the size-dependence of hydrological vulnerability, in concert with increasingly severe drought events, may shape future responses of stand-level biomass production to continued warming and increasing carbon dioxide concentration in the region.

Effect of different tree mortality patterns on stand development in the forest model SIBYLA

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Trombik Jiří

2016-09-01

Full Text Available Forest mortality critically affects stand structure and the quality of ecosystem services provided by forests. Spruce bark beetle (Ips typographus generates rather complex infestation and mortality patterns, and implementation of such patterns in forest models is challenging. We present here the procedure, which allows to simulate the bark beetle-related tree mortality in the forest dynamics model Sibyla. We explored how sensitive various production and stand structure indicators are to tree mortality patterns, which can be generated by bark beetles. We compared the simulation outputs for three unmanaged forest stands with 40, 70 and 100% proportion of spruce as affected by the disturbance-related mortality that occurred in a random pattern and in a patchy pattern. The used tree species and age class-specific mortality rates were derived from the disturbance-related mortality records from Slovakia. The proposed algorithm was developed in the SQLite using the Python language, and the algorithm allowed us to define the degree of spatial clustering of dead trees ranging from a random distribution to a completely clustered distribution; a number of trees that died in either mode is set to remain equal. We found significant differences between the long-term developments of the three investigated forest stands, but we found very little effect of the tested mortality modes on stand increment, tree species composition and diversity, and tree size diversity. Hence, our hypothesis that the different pattern of dead trees emergence should affect the competitive interactions between trees and regeneration, and thus affect selected productivity and stand structure indicators was not confirmed.

Air pollution removal by trees in public green spaces in Strasbourg city, France

Science.gov (United States)

Wissal Selmi; Christiane Weber; Emmanuel Riviere; Nadege Blond; Lotfi Mehdi; David Nowak

2016-01-01

This study integrates i-Tree Eco model in order to estimate air pollution removal by urban trees in Strasbourg city, France. Applied for the first time in a French city, the model shows that public trees, i.e., trees managed by the city, removed about 88 t of pollutants during one year period (from July 2012 to June 2013): about 1 ton for CO; 14 tons for NO2...

Community assessment of tropical tree biomass

DEFF Research Database (Denmark)

Theilade, Ida; Rutishauser, Ervan; Poulsen, Michael K.

2015-01-01

Background REDD+ programs rely on accurate forest carbon monitoring. Several REDD+ projects have recently shown that local communities can monitor above ground biomass as well as external professionals, but at lower costs. However, the precision and accuracy of carbon monitoring conducted by local...... communities have rarely been assessed in the tropics. The aim of this study was to investigate different sources of error in tree biomass measurements conducted by community monitors and determine the effect on biomass estimates. Furthermore, we explored the potential of local ecological knowledge to assess...... measurement, with special attention given to large and odd-shaped trees. A better understanding of traditional classification systems and concepts is required for local tree identifications and wood density estimates to become useful in monitoring of biomass and tree diversity....

Simulation of Drought-induced Tree Mortality Using a New Individual and Hydraulic Trait-based Model (S-TEDy)

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Sinha, T.; Gangodagamage, C.; Ale, S.; Frazier, A. G.; Giambelluca, T. W.; Kumagai, T.; Nakai, T.; Sato, H.

2017-12-01

Drought-related tree mortality at a regional scale causes drastic shifts in carbon and water cycling in Southeast Asian tropical rainforests, where severe droughts are projected to occur more frequently, especially under El Niño conditions. To provide a useful tool for projecting the tropical rainforest dynamics under climate change conditions, we developed the Spatially Explicit Individual-Based (SEIB) Dynamic Global Vegetation Model (DGVM) applicable to simulating mechanistic tree mortality induced by the climatic impacts via individual-tree-scale ecophysiology such as hydraulic failure and carbon starvation. In this study, we present the new model, SEIB-originated Terrestrial Ecosystem Dynamics (S-TEDy) model, and the computation results were compared with observations collected at a field site in a Bornean tropical rainforest. Furthermore, after validating the model's performance, numerical experiments addressing a future of the tropical rainforest were conducted using some global climate model (GCM) simulation outputs.

Hydraulic Function in Australian Tree Species during Drought-Induced Mortality

Science.gov (United States)

Tissue, D.; Maier, C.; Creek, D.; Choat, B.

2016-12-01

Drought induced tree mortality and decline are key issues facing forest ecology and management. Here, we primarily investigated the hydraulic limitations underpinning drought-induced mortality in three Australian tree species. Using field-based large rainout shelters, three angiosperm species (Casuarina cunninghamiana, Eucalyptus sideroxylon, Eucalyptus tereticornis) were subjected to two successive drought and recovery cycles, prior to a subsequent long and extreme drought to mortality; total duration of experiment was 2.5 years. Leaf gas exchange, leaf and stem hydraulics, and carbon reserves were monitored during the experiment. Trees died as a result of failure in the hydraulic transport system, primarily related to water stress induced embolism. Stomatal closure occurred prior to the induction of significant embolism in the stem xylem of all species. Nonetheless, trees suffered a rapid decline in xylem water potential and increase in embolism during the severe drought treatment. Trees died at water potentials causing greater than 90% loss of hydraulic conductivity in the stem, providing support for the theory that lethal water potential is correlated with complete loss of hydraulic function in the stem xylem of angiosperms.

Trees and the City: Diversity and Composition along a Neotropical Gradient of Urbanization

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Rubén Ortega-Álvarez

2011-01-01

Full Text Available In this study we assessed tree species richness, density, and composition patterns along a gradient of urbanization of a megacity. Our results show that total, native, and exotic tree densities were highest in green areas where larger spaces are considered for greening purposes. Conversely, total, native, and exotic tree species richness were highest in land uses with intermediate levels of urban development (residential, residential-commercial areas. Not finding highest tree species richness in less developed urban areas suggests that cultural factors may shape the array of species that are planted within cities. Supporting this, tree composition analyses showed that green areas are comprised of different tree species when compared to the rest of the studied urban land uses. Thus, our results suggest that, to increase the ecological quality of cities, residents and managers should be encouraged to select a greater variety of trees to promote heterogeneous green areas.

Disentangling the diversity of arboreal ant communities in tropical forest trees.

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Klimes, Petr; Fibich, Pavel; Idigel, Cliffson; Rimandai, Maling

2015-01-01

Tropical canopies are known for their high abundance and diversity of ants. However, the factors which enable coexistence of so many species in trees, and in particular, the role of foragers in determining local diversity, are not well understood. We censused nesting and foraging arboreal ant communities in two 0.32 ha plots of primary and secondary lowland rainforest in New Guinea and explored their species diversity and composition. Null models were used to test if the records of species foraging (but not nesting) in a tree were dependent on the spatial distribution of nests in surrounding trees. In total, 102 ant species from 389 trees occurred in the primary plot compared with only 50 species from 295 trees in the secondary forest plot. However, there was only a small difference in mean ant richness per tree between primary and secondary forest (3.8 and 3.3 sp. respectively) and considerably lower richness per tree was found only when nests were considered (1.5 sp. in both forests). About half of foraging individuals collected in a tree belonged to species which were not nesting in that tree. Null models showed that the ants foraging but not nesting in a tree are more likely to nest in nearby trees than would be expected at random. The effects of both forest stage and tree size traits were similar regardless of whether only foragers, only nests, or both datasets combined were considered. However, relative abundance distributions of species differed between foraging and nesting communities. The primary forest plot was dominated by native ant species, whereas invasive species were common in secondary forest. This study demonstrates the high contribution of foragers to arboreal ant diversity, indicating an important role of connectivity between trees, and also highlights the importance of primary vegetation for the conservation of native ant communities.

Introducing a longitudinal study of community gardeners and gardens in New York City

Science.gov (United States)

Erika S. Svendsen; Lindsay K. Campbell; Nancy Falxa-Raymond; Jessica Northridge; Edie. Stone

2012-01-01

For almost a decade, the NYC Department of Parks and Recreation GreenThumb program has collected data about hundreds of New York City community gardens citywide to understand how these gardens function. Building on a data set that includes surveys and interviews conducted periodically with garden representatives since 2003, GreenThumb and USDA Forest Service...

Calculating the green in green: What's an urban tree worth?

Science.gov (United States)

Gail Wells; Geoffrey Donovan

2010-01-01

For urban dwellers, trees soften a city’s hard edges and surfaces, shade homes and streets, enhance neighborhood beauty, filter the air, mitigate storm runoff, and absorb carbon dioxide. Trees may even reduce crime and improve human health. However, these benefits have not been well quantified, making it difficult for urban planners and property owners to weigh their...

The influence of chloride deicers on mineral nutrition and the health status of roadside trees in the city of Kielce, Poland.

Science.gov (United States)

Gałuszka, Agnieszka; Migaszewski, Zdzisław M; Podlaski, Rafał; Dołęgowska, Sabina; Michalik, Artur

2011-05-01

Application of chemical road deicers has a negative impact on roadside vegetation. Every year, the trees in cities suffer from direct and indirect effects of salt application for winter road maintenance. To elucidate this problem in the city of Kielce, the chemistry of snow, soil, tree bark, and leaf samples has been investigated together with an assessment of the health status of the trees. Twelve investigation sites were selected along the roads with different traffic intensity. Snow samples were collected twice during the winter and analyzed for pH, EC, Na(+), Ca(2+), Mg(2+), and Cl(-). In soil (collected from two depth intervals), tree bark, and leaf samples, the concentrations of B, Ca, Fe, K, Mg, Mn, N, Na, P, S, and Zn were determined. The contents of total organic carbon (TOC) in soils, as well as the pH of soil and tree bark samples were also measured. Negative symptoms revealed by roadside trees included the loss of assimilative apparatus and decreased vitality. The results of chemical analyses indicated that the snowmelt might be a substantial source of chloride ions and alkalizing substances that influenced higher pH of soils. The soil samples displayed elevated concentrations of S and Zn and lower than typical for soil contents of B, Mg, and TOC. The pH of alkaline soils favored greater bioavailability of B and reduced bioavailability of Na and Zn by the trees examined.

Desert Southwest Community Tree Guide: Benefits, Costs and Strategic Planting

Science.gov (United States)

Greg McPherson; J.R. Simpson; P.J. Peper; S.E. Maco; Q. Xiao; E. Mulrean

2004-01-01

This report quantifies benefits and costs for typical large-, medium-, small-stature, deciduous trees (Fraxinus uhdei, Prosopis chilensis, Acacia farnesiana), as well as a conifer (Pinus halapensis). The analysis assumed that trees were planted in a residential yard site or a public (street/park) site, a 40-year time frame, and...

Modelling dimensional growth of three street tree species in the ...

African Journals Online (AJOL)

The results could also be used in the process of modelling energy use reduction, air pollution uptake, rainfall interception, carbon sequestration and microclimate modification of urban forests such as those found in the City of Tshwane. Keywords: allometry; regression; size relationships; tree growth; urban forests. Southern ...

Northeast community tree guide: benefits, costs, and strategic planting

Science.gov (United States)

E. Gregory McPherson; James R. Simpson; Paula J. Peper; Shelley L. Gardner; Kelaine E. Vargas; Qingfu Xiao

2007-01-01

Trees make our cities more attractive and provide many ecosystem services, including air quality improvement, energy conservation, stormwater interception, and atmospheric carbon dioxide reduction. These benefits must be weighed against the costs of maintaining trees, including planting, pruning, irrigation, administration, pest control, liability, cleanup, and removal...

Does raking basal duff affect tree growth rates or mortality?

Science.gov (United States)

Erin Noonan-Wright; Sharon M. Hood; Danny R. Cluck

2010-01-01

Mortality and reduced growth rates due to raking accumulated basal duff were evaluated for old, large-diameter ponderosa and Jeffrey pine trees on the Lassen National Forest, California. No fire treatments were included to isolate the effect of raking from fire. Trees were monitored annually for 5 years after the raking treatment for mortality and then cored to measure...

Adult tree swallow survival on the polychlorinated biphenyl-contaminated Hudson River, New York, USA, between 2006 and 2010

Science.gov (United States)

Custer, Christine M.; Custer, Thomas W.; Hines, James E.

2012-01-01

The upper Hudson River basin in east central New York, USA, is highly contaminated, primarily with polychlorinated biphenyls (PCBs). Reduced adult survival has been documented in tree swallows (Tachycineta bicolor) at a similarly PCB-contaminated river system in western Massachusetts. The purpose of the present study was to assess whether adult survival of tree swallows was likewise affected in the Hudson River basin. Between 2006 and 2010, a total of 521 female tree swallows were banded, of which 148 were retrapped at least once. The authors used Program MARK and an information theoretic approach to test the hypothesis that PCB contamination reduced annual survival of female tree swallows. The model that best described the processes that generated the capture history data included covariate effects of year and female plumage coloration on survival but not PCB/river. Annual survival rates of brown-plumaged females (mostly one year old) were generally lower (mean phi = 0.39) than those of blue-plumaged females (mean phi = 0.50, one year or older). Poor early spring weather in 2007 was associated with reduced survival in both plumage-color groups compared to later years. Models with the effects of PCB exposure on survival (all ΔAICc values >5.0) received little support.

Biogeochemical hotspots following a simulated tree mortality event of southern pine beetle

Science.gov (United States)

Siegert, C. M.; Renninger, H. J.; Karunarathna, S.; Hornslein, N.; Riggins, J. J.; Clay, N. A.; Tang, J. D.; Chaney, B.; Drotar, N.

2017-12-01

Disturbances in forest ecosystems can alter functions like productivity, respiration, and nutrient cycling through the creation of biogeochemical hotspots. These events occur sporadically across the landscape, leading to uncertainty in terrestrial biosphere carbon models, which have yet to capture the full complexity of biotic and abiotic factors driving ecological processes in the terrestrial environment. Given the widespread impact of southern pine beetle on forest ecosystems throughout the southeastern United States, it is critical to management and planning activities to understand the role of these disturbances. As such, we hypothesize that bark beetle killed trees create biogeochemical hotspots in the soils surrounding their trunk as they undergo mortality due to (1) increased soil moisture from reductions in plant water uptake and increased stemflow production, (2) enhanced canopy-derived inputs of carbon and nitrogen, and (3) increased microbial activity and root mortality. In 2015, a field experiment to mimic a southern pine beetle attack was established by girdling loblolly pine trees. Subsequent measurements of throughfall and stemflow for water quantity and quality, transpiration, stem respiration, soil respiration, and soil chemistry were used to quantify the extent of spatial and temporal impacts of tree mortality on carbon budgets. Compared to control trees, girdled trees exhibited reduced water uptake within the first 6 months of the study and succumbed to mortality within 18 months. Over two years, the girdled trees generated 33% more stemflow than control trees (7836 vs. 5882 L m-2). Preliminary analysis of carbon and nitrogen concentrations and dissolved organic matter quality are still pending. In the surrounding soils, C:N ratios were greater under control trees (12.8) than under girdled trees (12.1), which was driven by an increase in carbon around control trees (+0.13 mg C mg-1 soil) and not a decrease around girdled trees (-0.01 mg C mg-1

Drought, tree mortality, and wildfire in forests adapted to frequent fire

Science.gov (United States)

Scott L Stephens; Brandon M Collins; Christopher J Fettig; Mark A Finney; Chad M Hoffman; Eric E Knapp; Malcolm P North; Hugh Safford; Rebecca B Wayman

2018-01-01

Massive tree mortality has occurred rapidly in frequent-fire-adapted forests of the Sierra Nevada, California. This mortality is a product of acute drought compounded by the long-established removal of a key ecosystem process: frequent, low- to moderate-intensity fire. The recent tree mortality has many implications for the future of these forests and the ecological...

Habitat filtering across tree life stages in tropical forest communities

Science.gov (United States)

Baldeck, C. A.; Harms, K. E.; Yavitt, J. B.; John, R.; Turner, B. L.; Valencia, R.; Navarrete, H.; Bunyavejchewin, S.; Kiratiprayoon, S.; Yaacob, A.; Supardi, M. N. N.; Davies, S. J.; Hubbell, S. P.; Chuyong, G. B.; Kenfack, D.; Thomas, D. W.; Dalling, J. W.

2013-01-01

Tropical tree communities are shaped by local-scale habitat heterogeneity in the form of topographic and edaphic variation, but the life-history stage at which habitat associations develop remains poorly understood. This is due, in part, to the fact that previous studies have not accounted for the widely disparate sample sizes (number of stems) that result when trees are divided into size classes. We demonstrate that the observed habitat structuring of a community is directly related to the number of individuals in the community. We then compare the relative importance of habitat heterogeneity to tree community structure for saplings, juveniles and adult trees within seven large (24–50 ha) tropical forest dynamics plots while controlling for sample size. Changes in habitat structuring through tree life stages were small and inconsistent among life stages and study sites. Where found, these differences were an order of magnitude smaller than the findings of previous studies that did not control for sample size. Moreover, community structure and composition were very similar among tree sub-communities of different life stages. We conclude that the structure of these tropical tree communities is established by the time trees are large enough to be included in the census (1 cm diameter at breast height), which indicates that habitat filtering occurs during earlier life stages. PMID:23843384

Tree mortality from drought, insects, and their interactions in a changing climate

Science.gov (United States)

Anderegg, William R.L.; Hicke, Jeffrey A.; Fisher, Rosie A.; Allen, Craig D.; Aukema, Juliann E.; Bentz, Barbara; Hood, Sharon; Lichstein, Jeremy W.; Macalady, Alison K.; McDowell, Nate G.; Pan, Yude; Raffa, Kenneth; Sala, Anna; Shaw, John D.; Stephenson, Nathan L.; Tague, Christina L.; Zeppel, Melanie

2015-01-01

Climate change is expected to drive increased tree mortality through drought, heat stress, and insect attacks, with manifold impacts on forest ecosystems. Yet, climate-induced tree mortality and biotic disturbance agents are largely absent from process-based ecosystem models. Using data sets from the western USA and associated studies, we present a framework for determining the relative contribution of drought stress, insect attack, and their interactions, which is critical for modeling mortality in future climates. We outline a simple approach that identifies the mechanisms associated with two guilds of insects – bark beetles and defoliators – which are responsible for substantial tree mortality. We then discuss cross-biome patterns of insect-driven tree mortality and draw upon available evidence contrasting the prevalence of insect outbreaks in temperate and tropical regions. We conclude with an overview of tools and promising avenues to address major challenges. Ultimately, a multitrophic approach that captures tree physiology, insect populations, and tree–insect interactions will better inform projections of forest ecosystem responses to climate change.

Widespread Amazon forest tree mortality from a single cross-basin squall line event

Science.gov (United States)

Negrón-Juárez, Robinson I.; Chambers, Jeffrey Q.; Guimaraes, Giuliano; Zeng, Hongcheng; Raupp, Carlos F. M.; Marra, Daniel M.; Ribeiro, Gabriel H. P. M.; Saatchi, Sassan S.; Nelson, Bruce W.; Higuchi, Niro

2010-08-01

Climate change is expected to increase the intensity of extreme precipitation events in Amazonia that in turn might produce more forest blowdowns associated with convective storms. Yet quantitative tree mortality associated with convective storms has never been reported across Amazonia, representing an important additional source of carbon to the atmosphere. Here we demonstrate that a single squall line (aligned cluster of convective storm cells) propagating across Amazonia in January, 2005, caused widespread forest tree mortality and may have contributed to the elevated mortality observed that year. Forest plot data demonstrated that the same year represented the second highest mortality rate over a 15-year annual monitoring interval. Over the Manaus region, disturbed forest patches generated by the squall followed a power-law distribution (scaling exponent α = 1.48) and produced a mortality of 0.3-0.5 million trees, equivalent to 30% of the observed annual deforestation reported in 2005 over the same area. Basin-wide, potential tree mortality from this one event was estimated at 542 ± 121 million trees, equivalent to 23% of the mean annual biomass accumulation estimated for these forests. Our results highlight the vulnerability of Amazon trees to wind-driven mortality associated with convective storms. Storm intensity is expected to increase with a warming climate, which would result in additional tree mortality and carbon release to the atmosphere, with the potential to further warm the climate system.

Radiofrequency radiation injures trees around mobile phone base stations.

Science.gov (United States)

Waldmann-Selsam, Cornelia; Balmori-de la Puente, Alfonso; Breunig, Helmut; Balmori, Alfonso

2016-12-01

In the last two decades, the deployment of phone masts around the world has taken place and, for many years, there has been a discussion in the scientific community about the possible environmental impact from mobile phone base stations. Trees have several advantages over animals as experimental subjects and the aim of this study was to verify whether there is a connection between unusual (generally unilateral) tree damage and radiofrequency exposure. To achieve this, a detailed long-term (2006-2015) field monitoring study was performed in the cities of Bamberg and Hallstadt (Germany). During monitoring, observations and photographic recordings of unusual or unexplainable tree damage were taken, alongside the measurement of electromagnetic radiation. In 2015 measurements of RF-EMF (Radiofrequency Electromagnetic Fields) were carried out. A polygon spanning both cities was chosen as the study site, where 144 measurements of the radiofrequency of electromagnetic fields were taken at a height of 1.5m in streets and parks at different locations. By interpolation of the 144 measurement points, we were able to compile an electromagnetic map of the power flux density in Bamberg and Hallstadt. We selected 60 damaged trees, in addition to 30 randomly selected trees and 30 trees in low radiation areas (n=120) in this polygon. The measurements of all trees revealed significant differences between the damaged side facing a phone mast and the opposite side, as well as differences between the exposed side of damaged trees and all other groups of trees in both sides. Thus, we found that side differences in measured values of power flux density corresponded to side differences in damage. The 30 selected trees in low radiation areas (no visual contact to any phone mast and power flux density under 50μW/m 2 ) showed no damage. Statistical analysis demonstrated that electromagnetic radiation from mobile phone masts is harmful for trees. These results are consistent with the fact

Ghost-tree: creating hybrid-gene phylogenetic trees for diversity analyses.

Science.gov (United States)

Fouquier, Jennifer; Rideout, Jai Ram; Bolyen, Evan; Chase, John; Shiffer, Arron; McDonald, Daniel; Knight, Rob; Caporaso, J Gregory; Kelley, Scott T

2016-02-24

Fungi play critical roles in many ecosystems, cause serious diseases in plants and animals, and pose significant threats to human health and structural integrity problems in built environments. While most fungal diversity remains unknown, the development of PCR primers for the internal transcribed spacer (ITS) combined with next-generation sequencing has substantially improved our ability to profile fungal microbial diversity. Although the high sequence variability in the ITS region facilitates more accurate species identification, it also makes multiple sequence alignment and phylogenetic analysis unreliable across evolutionarily distant fungi because the sequences are hard to align accurately. To address this issue, we created ghost-tree, a bioinformatics tool that integrates sequence data from two genetic markers into a single phylogenetic tree that can be used for diversity analyses. Our approach starts with a "foundation" phylogeny based on one genetic marker whose sequences can be aligned across organisms spanning divergent taxonomic groups (e.g., fungal families). Then, "extension" phylogenies are built for more closely related organisms (e.g., fungal species or strains) using a second more rapidly evolving genetic marker. These smaller phylogenies are then grafted onto the foundation tree by mapping taxonomic names such that each corresponding foundation-tree tip would branch into its new "extension tree" child. We applied ghost-tree to graft fungal extension phylogenies derived from ITS sequences onto a foundation phylogeny derived from fungal 18S sequences. Our analysis of simulated and real fungal ITS data sets found that phylogenetic distances between fungal communities computed using ghost-tree phylogenies explained significantly more variance than non-phylogenetic distances. The phylogenetic metrics also improved our ability to distinguish small differences (effect sizes) between microbial communities, though results were similar to non

Host associations and beta diversity of fungal endophyte communities in New Guinea rainforest trees.

Science.gov (United States)

Vincent, J B; Weiblen, G D; May, G

2016-02-01

Processes shaping the distribution of foliar fungal endophyte species remain poorly understood. Despite increasing evidence that these cryptic fungal symbionts of plants mediate interactions with pathogens and herbivores, there remain basic questions regarding the extent to which dispersal limitation and host specificity might shape fungal endophyte community composition in rainforests. To assess the relative importance of spatial pattern and host specificity, we isolated fungi from a sample of mapped trees in lowland Papua New Guinea. Sequences of the internal transcribed spacer (ITS) region were obtained for 2079 fungal endophytes from three sites and clustered into molecular operational taxonomic units (MOTUs) at 95% similarity. Multivariate analyses suggest that host affinity plays a significant role in structuring endophyte community composition whereas there was no evidence of endophyte spatial pattern at the scale of tens to hundreds of metres. Differences in endophyte communities between sampled trees were weakly correlated with variation in foliar traits but not with tree species relatedness. The dominance of relatively few generalist endophytes and the presence of a large number of rare MOTUs was a consistent observation at three sites separated by hundreds of kilometres and regional turnover was low. Host specificity appears to play a relatively weak but more important role than dispersal limitation in shaping the distribution of fungal endophyte communities in New Guinea forests. Our results suggest that in the absence of strong ecological gradients and host turnover, beta diversity of endophyte communities could be low in large areas of contiguous forest. © 2015 John Wiley & Sons Ltd.

Plant community development within the F- and H-Area tree-kill zone

Energy Technology Data Exchange (ETDEWEB)

Nelson, E.A.; Westbury, H.M. Jr.

1994-10-01

The F- and H-Area Seepage Basins received liquid waste from the F and H chemical separation facilities from 1955 through 1988. Tree mortality in seepline fed wetlands down-slope from the basins was observed in the late 1970`s, and investigations were conducted to determine the cause and source of the impacts. Analysis of the soil and water in the tree-kill zones demonstrated a strong chemical linkage with the F- and H-Area seepage basins. Although no single cause of the mortality was determined, it was believed to be the result of interactions of alterations in the hydrology and erosional deposition, along with lowering of pH and increased conductivity, sodium, aluminum, and nitrogen compounds. A mild drought during the growing season may also have increased the concentration of the chemical contaminants in the soils matrix. In 1988, the F- and H-Area Seepage Basins were closed and covered with a clay cap to reduce the rate of dispersion of the contaminants in the soil beneath the basins. Subsequent studies of the chemical composition of the tree-kill zone groundwater and toxicological characteristics of the seepline soil have shown a reduced contaminant flux. In 1993, an initial vegetation study was undertaken to determine the level of recovery by the plant communities in the tree-kill zones. This study repeats the initial vegetation investigation in order to further analyze and characterize the recovery of plant communities in the zones after an additional year of growth.

Los Angeles 1-Million tree canopy cover assessment

Science.gov (United States)

Gregory E. McPherson; James R. Simpson; Qingfu Xiao; Wu Chunxia

2008-01-01

The Million Trees LA initiative intends to chart a course for sustainable growth through planting and stewardship of trees. The purpose of this study was to measure Los Angeles's existing tree canopy cover (TCC), determine if space exists for 1 million additional trees, and estimate future benefits from the planting. High resolution QuickBird remote sensing data,...

Evaluation of numerical flow and dispersion simulations for street canyons with avenue-like tree planting by comparison with wind tunnel data

NARCIS (Netherlands)

Gromke, C.B.; Buccolieri, R.; Sabatino, Di S.; Ruck, B.

2008-01-01

Flow and traffic-originated pollutant dispersion in an urban street canyon with avenue-like tree planting have been studied by means of wind tunnel and CFD investigations. The study comprises tree planting of different crown porosity, planted in two rows within a canyon of street width to building

Contrasting natural regeneration and tree planting in fourteen North American cities

Science.gov (United States)

David J. Nowak

2012-01-01

Field data from randomly located plots in 12 cities in the United States and Canada were used to estimate the proportion of the existing tree population that was planted or occurred via natural regeneration. In addition, two cities (Baltimore and Syracuse) were recently re-sampled to estimate the proportion of newly established trees that were planted. Results for the...

Nonstructural leaf carbohydrate dynamics of Pinus edulis during drought-induced tree mortality reveal role for carbon metabolism in mortality mechanism.

Science.gov (United States)

Adams, Henry D; Germino, Matthew J; Breshears, David D; Barron-Gafford, Greg A; Guardiola-Claramonte, Maite; Zou, Chris B; Huxman, Travis E

2013-03-01

Vegetation change is expected with global climate change, potentially altering ecosystem function and climate feedbacks. However, causes of plant mortality, which are central to vegetation change, are understudied, and physiological mechanisms remain unclear, particularly the roles of carbon metabolism and xylem function. We report analysis of foliar nonstructural carbohydrates (NSCs) and associated physiology from a previous experiment where earlier drought-induced mortality of Pinus edulis at elevated temperatures was associated with greater cumulative respiration. Here, we predicted faster NSC decline for warmed trees than for ambient-temperature trees. Foliar NSC in droughted trees declined by 30% through mortality and was lower than in watered controls. NSC decline resulted primarily from decreased sugar concentrations. Starch initially declined, and then increased above pre-drought concentrations before mortality. Although temperature did not affect NSC and sugar, starch concentrations ceased declining and increased earlier with higher temperatures. Reduced foliar NSC during lethal drought indicates a carbon metabolism role in mortality mechanism. Although carbohydrates were not completely exhausted at mortality, temperature differences in starch accumulation timing suggest that carbon metabolism changes are associated with time to death. Drought mortality appears to be related to temperature-dependent carbon dynamics concurrent with increasing hydraulic stress in P. edulis and potentially other similar species. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Monitoring tree mortality in mature Douglas-fir forests: size and species matter

Science.gov (United States)

Background/Question/MethodsA regional increase in tree mortality rates associated with climate change will influence forest health and ecosystem services, including water quality and quantity. In recent decades, accelerated tree mortality has occurred in some, but not all, fores...

Oak Wilt: People and Trees, A Community Approach to Management

Science.gov (United States)

J. Juzwik; S. Cook; L. Haugen; J. Elwell

2004-01-01

Version 1.3. This self-paced short course on CD-ROM was designed as a learning tool for urban and community foresters, city administrators, tree inspectors, parks and recreation staff, and others involved in oak wilt management.Click the "View or print this publication" link below to request your Oak Wilt: People and...

Central Florida community tree guide: benefits, costs, and strategic planting

Science.gov (United States)

Paula J. Peper; E. Gregory McPherson; James R. Simpson; Shannon N. Albers; Qingfu Xiao

2010-01-01

Trees make our cities more attractive and provide many ecosystem services, including air quality improvement, energy conservation, stormwater interception, and atmospheric carbon dioxide reduction. These benefits must be weighed against the costs of maintaining trees, including planting, pruning, irrigation, administration, pest control, liability, cleanup, and removal...

Grading of Parameters for Urban Tree Inventories by City Officials, Arborists, and Academics Using the Delphi Method

Science.gov (United States)

Östberg, Johan; Delshammar, Tim; Wiström, Björn; Nielsen, Anders Busse

2013-03-01

Tree inventories are expensive to conduct and update, so every inventory carried out must be maximized. However, increasing the number of constituent parameters increases the cost of performing and updating the inventory, illustrating the need for careful parameter selection. This article reports the results of a systematic expert rating of tree inventories aiming to quantify the relative importance of each parameter. Using the Delphi method, panels comprising city officials, arborists, and academics rated a total of 148 parameters. The total mean score, the top ranking parameters, which can serve as a guide for decision-making at practical level and for standardization of tree inventories, were: Scientific name of the tree species and genera, Vitality, Coordinates, Hazard class, and Identification number. The study also examined whether the different responsibilities and usage of urban tree databases among organizations and people engaged in urban tree inventories affected their prioritization. The results revealed noticeable dissimilarities in the ranking of parameters between the panels, underlining the need for collaboration between the research community and those commissioning, administrating, and conducting inventories. Only by applying such a transdisciplinary approach to parameter selection can urban tree inventories be strengthened and made more relevant.

Identifying Perceived Neighborhood Stressors Across Diverse Communities in New York City.

Science.gov (United States)

Shmool, Jessie L C; Yonas, Michael A; Newman, Ogonnaya Dotson; Kubzansky, Laura D; Joseph, Evelyn; Parks, Ana; Callaway, Charles; Chubb, Lauren G; Shepard, Peggy; Clougherty, Jane E

2015-09-01

There is growing interest in the role of psychosocial stress in health disparities. Identifying which social stressors are most important to community residents is critical for accurately incorporating stressor exposures into health research. Using a community-academic partnered approach, we designed a multi-community study across the five boroughs of New York City to characterize resident perceptions of key neighborhood stressors. We conducted 14 community focus groups; two to three in each borough, with one adolescent group and one Spanish-speaking group per borough. We then used systematic content analysis and participant ranking data to describe prominent neighborhood stressors and identify dominant themes. Three inter-related themes regarding the social and structural sources of stressful experiences were most commonly identified across neighborhoods: (1) physical disorder and perceived neglect, (2) harassment by police and perceived safety and (3) gentrification and racial discrimination. Our findings suggest that multiple sources of distress, including social, political, physical and economic factors, should be considered when investigating health effects of community stressor exposures and psychological distress. Community expertise is essential for comprehensively characterizing the range of neighborhood stressors that may be implicated in psychosocial exposure pathways.

Presence of Counterfeit Marlboro Gold Packs in Licensed Retail Stores in New York City: Evidence From Test Purchases.

Science.gov (United States)

Kurti, Marin; He, Yi; Silver, Diana; Giorgio, Margaret; von Lampe, Klaus; Macinko, James; Ye, Hua; Tan, Fidelis; Mei, Victoria

2018-05-26

There are no independent studies measuring the availability of premium brand counterfeit cigarettes in New York City from licensed retailers. We forensically analyzed the cigarette packaging of Marlboro Gold (n = 1021) purchased from licensed tobacco retailers in New York City, using ultraviolet irradiation and light microscopy to determine whether they were counterfeit. We find that while only 0.5% (n = 5) of our sample exhibits at least one characteristic synonymous with counterfeit packaging, none of our packs can be conclusively classified as counterfeit. We do not find any counterfeit Marlboro Gold packs purchased at full price from licensed cigarette retailers throughout New York City. Future research using test purchases should include other venues (eg, street and online) and specifically ask for discounts to ascertain the overall presence of counterfeit cigarettes. This is the first study to independently measure the availability of counterfeit cigarette packs purchased at full price from licensed retailers in New York City. We find that none of the Marlboro Gold packs purchased from licensed cigarette retailers are counterfeit.

Dust retaining properties of leaves of some tree species

Energy Technology Data Exchange (ETDEWEB)

Gusev, M I

1960-05-01

A study was made in Tashkent, Russia of the dust-retaining power of leaves of several tree species. Investigations were made in a park where these tree species were growing in close proximity, exposed to the effects of dust from the main city street and from the highway passing through the park. Observations on the dust-retaining power of leaves were made mostly during the summer and fall months. The dust-retaining power of leaves of different tree species varied with the dust concentration in the air. In the summer and fall when rains are scarce a steady accumulation of dust was observed on the surface of the leaves. 1 table.

Mastication and prescribed fire influences on tree mortality and predicted fire behavior in ponderosa pine

Science.gov (United States)

Alicia L. Reiner; Nicole M. Vaillant; Scott N. Dailey

2012-01-01

The purpose of this study was to provide land managers with information on potential wildfire behavior and tree mortality associated with mastication and masticated/fire treatments in a plantation. Additionally, the effect of pulling fuels away from tree boles before applying fire treatment was studied in relation to tree mortality. Fuel characteristics and tree...

Numerical modeling of flow and pollutant dispersion in street canyons with tree planting

NARCIS (Netherlands)

Balczó, M.; Gromke, C.B.; Ruck, B.

2009-01-01

Numerical simulations of the impact of tree planting on airflow and traffic pollutant dispersion in urban street canyons have been performed using the commercial CFD (Computational Fluid Dynamics) code MISKAM. A k-e turbulence model including additional terms for the treatment of vegetation, has

Using inventory data to determine the impact of drought on tree mortality

Science.gov (United States)

Greg C. Liknes; Christopher W. Woodall; Charles H. Perry

2012-01-01

Drought has been the subject of numerous recent studies that hint at an acceleration of tree mortality due to climate change. In particular, a recent global survey of tree mortality events implicates drought as the cause of quaking aspen mortality in Minnesota, USA in 2007. In this study, data from the Forest Inventory and Analysis program of the USDA Forest Service...

Microbial Community Patterns Associated with Automated Teller Machine Keypads in New York City.

Science.gov (United States)

Bik, Holly M; Maritz, Julia M; Luong, Albert; Shin, Hakdong; Dominguez-Bello, Maria Gloria; Carlton, Jane M

2016-01-01

In densely populated urban environments, the distribution of microbes and the drivers of microbial community assemblages are not well understood. In sprawling metropolitan habitats, the "urban microbiome" may represent a mix of human-associated and environmental taxa. Here we carried out a baseline study of automated teller machine (ATM) keypads in New York City (NYC). Our goal was to describe the biodiversity and biogeography of both prokaryotic and eukaryotic microbes in an urban setting while assessing the potential source of microbial assemblages on ATM keypads. Microbial swab samples were collected from three boroughs (Manhattan, Queens, and Brooklyn) during June and July 2014, followed by generation of Illumina MiSeq datasets for bacterial (16S rRNA) and eukaryotic (18S rRNA) marker genes. Downstream analysis was carried out in the QIIME pipeline, in conjunction with neighborhood metadata (ethnicity, population, age groups) from the NYC Open Data portal. Neither the 16S nor 18S rRNA datasets showed any clustering patterns related to geography or neighborhood demographics. Bacterial assemblages on ATM keypads were dominated by taxonomic groups known to be associated with human skin communities ( Actinobacteria , Bacteroides , Firmicutes , and Proteobacteria ), although SourceTracker analysis was unable to identify the source habitat for the majority of taxa. Eukaryotic assemblages were dominated by fungal taxa as well as by a low-diversity protist community containing both free-living and potentially pathogenic taxa ( Toxoplasma , Trichomonas ). Our results suggest that ATM keypads amalgamate microbial assemblages from different sources, including the human microbiome, eukaryotic food species, and potentially novel extremophilic taxa adapted to air or surfaces in the built environment. DNA obtained from ATM keypads may thus provide a record of both human behavior and environmental sources of microbes. IMPORTANCE Automated teller machine (ATM) keypads represent

Tree mortality from a short-duration freezing event and global-change-type drought in a Southwestern piñon-juniper woodland, USA

Science.gov (United States)

2014-01-01

This study documents tree mortality in Big Bend National Park in Texas in response to the most acute one-year drought on record, which occurred following a five-day winter freeze. I estimated changes in forest stand structure and species composition due to freezing and drought in the Chisos Mountains of Big Bend National Park using permanent monitoring plot data. The drought killed over half (63%) of the sampled trees over the entire elevation gradient. Significant mortality occurred in trees up to 20 cm diameter (P Pinus cembroides Zucc. experienced the highest seedling and tree mortality (P droughts under climate change will likely cause even greater damage to trees that survived this record drought, especially if such events follow freezes. The results from this study highlight the vulnerability of trees in the Southwest to climatic change and that future shifts in forest structure can have large-scale community consequences. PMID:24949231

Evaluation of numerical flow and dispersion simulations for street canyons with avenue-like tree planting by comparison with wind tunnel data

OpenAIRE

Gromke, CB Christof; Buccolieri, R; Sabatino, S Di; Ruck, B

2008-01-01

Abstract: Flow and traffic-originated pollutant dispersion in an urban street canyon with avenue-like tree planting have been studied by means of wind tunnel and CFD investigations. The study comprises tree planting of different crown porosity, planted in two rows within a canyon of street width to building height ratio W/H = 2 and street length to building height ratio L/H = 10 exposed to a perpendicular approaching boundary layer flow. Numerical simulations have been performed with...

The Impact of Cigarette Excise Tax Increases on Purchasing Behaviors Among New York City Smokers

Science.gov (United States)

Coady, Micaela H.; Chan, Christina A.; Mbamalu, Ijeoma G.; Kansagra, Susan M.

2013-01-01

Objectives. We examined the relationship between cigarette excise tax increases and tax-avoidant purchasing behaviors among New York City adult smokers. Methods. We analyzed data from the city’s annual Community Health Survey to assess changes in rates of tax avoidance over time (2003–2010) and smokers’ responses to the 2008 state cigarette tax increase. Multivariable logistic regression analysis identified correlates of buying more cigarettes on the street in response to the increase. Results. After the 2002 tax increase, the percentage of smokers engaged in tax-avoidant behavior decreased with time from 30% in 2003 to 13% in 2007. Following the 2008 tax increase, 21% of smokers reported buying more cigarettes from another person on the street. Low-income, younger, Black, and Hispanic smokers were more likely than respondents with other sociodemographic characteristics to purchase more cigarettes on the street. Conclusions. To maximize public health impact, cigarette tax increases should be paired with efforts to limit the flow of untaxed cigarettes entering jurisdictions with high cigarette pack prices. PMID:23597382

MillionTreesNYC, Green Infrastructure and Urban Ecology Symposium March 5-6, 2010

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Erika S. Svendsen

2010-01-01

Full Text Available The MillionTreesNYC Subcommittee on Research and Evaluation was formed shortly following the 2007 launch of MillionTreesNYC, a citywide, public-private initiative with an ambitious goal: to plant and care for one million new trees across New York City’s five boroughs by 2017. Members of this committee are comprised of academics, government researchers and local practitioners with experience in the fields of natural resource management and community development.On March 5-6, 2010, over two hundred researchers and practitioners came together at The New School to showcase scientific innovation in the field of urban forestry and greening. The MillionTreesNYC, Green Infrastructure and Urban Ecology Research Symposium engaged professionals from a broad range of disciplines including sociology, planning, epidemiology, earth sciences, hydrology, forestry, ecology, and design who were uniquely positioned to discuss new ideas.

Schizophyllum commune: The main cause of dying trees of the Banja Luka arbored walks and parks

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Matavulj Milan N.

2013-01-01

reason for this was primarily due to Split-gill fungus and the restoration of arbored walks in the streets extremely polluted by engine fuel consumption in the zone of Mladena Stojanovića street. By analyzing the trees along the City of Banja Luka main street it could be concluded that, besides the appearance of suffocation of plants, due to wide asphalt surfaces that are located immediately next to the tree-trunks and heavy air pollution, fungi caused illnesses are the most important cause of the decline of trees. With its great adaptation to arid climate and ability to resist to the air pollution, Schizophyllum commune turned out to be the most aggressive and successful universal fungal invader of trees from old alleys, even threatening immuno­compromised human individuals. However, man and his direct or indirect impacts contrib­ute to the dying of trees much faster than the fungal pathogens in the busiest and most polluted Mladena Stojanovića street.

Secular changes in mortality disparities in New York City: a reexamination.

Science.gov (United States)

Althoff, Keri N; Karpati, Adam; Hero, Joachim; Matte, Thomas D

2009-09-01

Previously published analyses showed that inequalities in mortality rates between residents of poor and wealthy neighborhoods in New York City (NYC) narrowed between 1990 and 2000, but these trends may have been influenced by population in-migration and gentrification. The NYC public housing population has been less subject to these population shifts than those in other NYC neighborhoods. We compared changes in mortality rates (MRs) from 1989-1991 to 1999-2001 among residents of NYC census blocks consisting entirely of public housing residences with residents of nonpublic housing low-income and higher-income blocks. Public housing and nonpublic housing low-income blocks were those in census block groups with > or =50% of residents living at <1.5 times the federal poverty level (FPL); nonpublic housing higher-income blocks were those in census block groups with <50% of residents living at <1.5 times the FPL. Information on deaths was obtained from NYC's vital registry, and US Census data were used for denominators. Age-standardized all-cause MRs in public housing, low-income, and higher-income residents decreased between the decades by 16%, 28%, and 22%, respectively. While mortality rate ratios between low-income and higher-income residents narrowed by 8%, the relative disparity between public housing and low-income residents widened by 21%. Diseases amenable to prevention including malignancies, diabetes, and chronic lung disease contributed to the increased overall mortality disparity between public housing and lower-income residents. These findings temper previous findings that inequalities in the health of poor and wealthier NYC neighborhood residents have narrowed. NYC public housing residents should be a high-priority population for efforts to reduce health disparities.

Spatial variation in the parasite communities and genomic structure of urban rats in New York City.

Science.gov (United States)

Angley, L P; Combs, M; Firth, C; Frye, M J; Lipkin, I; Richardson, J L; Munshi-South, J

2018-02-01

rat parasite communities, indicating that rats across New York City are not reservoirs for a homogenous set of parasites and pathogens. As a result, the epidemiological risks may be similarly heterogeneous for people in urban habitats. © 2017 Blackwell Verlag GmbH.

Root and Branch Reform: Teaching City Kids about Urban Trees

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Walker, Mark

2017-01-01

In today's electronic age, suburban and city children are increasingly disconnected with the natural world. Studying trees allows children to learn about the world they live in and can teach a variety of useful topics contained within the National Curriculum in England. Knowledge of trees is specifically required in the science curriculum at key…

Herbivory of tropical rain forest tree seedlings correlates with future mortality.

Science.gov (United States)

Eichhorn, Markus P; Nilus, Reuben; Compton, Stephen G; Hartley, Sue E; Burslem, David F R P

2010-04-01

Tree seedlings in tropical rain forests are subject to both damage from natural enemies and intense interspecific competition. This leads to a trade-off in investment between defense and growth, and it is likely that tree species specialized to particular habitats tailor this balance to correspond with local resource availability. It has also been suggested that differential herbivore impacts among tree species may drive habitat segregation, favoring species adapted to particular resource conditions. In order to test these predictions, a reciprocal transplant experiment in Sabah, Malaysia, was established with seedlings of five species of Dipterocarpaceae. These were specialized to either alluvial (Hopea nervosa, Parashorea tomentella) or sandstone soils (Shorea multiflora, H. beccariana), or were locally absent (S. fallax). A total of 3000 seedlings were planted in paired gap and understory plots in five sites on alluvial and sandstone soils. Half of all seedlings were fertilized. Seedling growth and mortality were recorded in regular samples over 3.5 years, and rates of insect herbivore damage were estimated from censuses of foliar tissue loss on marked mature leaves and available young leaves. Greater herbivory rates on mature leaves had no measurable effects on seedling growth but were associated with a significantly increased likelihood of mortality during the following year. In contrast, new-leaf herbivory rates correlated with neither growth nor mortality. There were no indications of differential impacts of herbivory among the five species, nor between experimental treatments. Herbivory was not shown to influence segregation of species between soil types, although it may contribute toward differential survival among light habitats. Natural rates of damage were substantially lower than have been shown to influence tree seedling growth and mortality in previous manipulative studies.

[Effects of target tree tending on community structure and diversity in subtropical natural secondary shrubs].

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Zhang, Hui; Zhou, Guo Mo; Bai, Shang Bin; Wang, Yi Xiang; You, Yu Jie; Zhu, Ting Ting; Zhang, Hua Feng

2017-05-18

The typical natural secondary shrub community was chosen in Lin'an of Zhejiang Pro-vince to discover its possibility of restoration to arbor forest with three kinds of forest management models being taken, i.e., no care as control, closed forest management and target tree tending. Over four years growth, compared with control, closed forest management significantly increased average DBH and height by 130% and 50%, respectively, while 260% and 110% for target tree tending. In target tree tending plots, larger trees had been emerging with 4.5-8.5 cm diameter class and 4.5-8.5 m height class and formed a new storey of 4 m compared with control. The species biodiversity indexes at shrub layer were significantly increased in closed management plots, and did not decrease in target tree tending plots. Closed forest management did not change the tree species composition, following its previous succession direction. However, target tree tending increased the importance value of target species with the high potential succession direction of mixed coniferous-broadleaved forest. The results revealed that the secondary shrub community with target tree tending achieved more desired goals on DBH and height growth of dominant trees and species composition improvement compared with closed management. If the secondary shrub community could be managed when the operational conditions existed, target tree tending model should be selected to accelerate the restoration of shrub toward arbor forest.

Tree Mortality Decreases Water Availability and Ecosystem Resilience to Drought in Piñon-Juniper Woodlands in the Southwestern U.S.: Tree Mortality in Semiarid Biomes

Energy Technology Data Exchange (ETDEWEB)

Morillas, L. [Department of Biology, University of New Mexico, Albuquerque NM USA; Now at Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver British Columbia Canada; Pangle, R. E. [Department of Biology, University of New Mexico, Albuquerque NM USA; Maurer, G. E. [Department of Biology, University of New Mexico, Albuquerque NM USA; Now at Department of Environmental Science, Policy, and Management, University of California, Berkeley CA USA; Pockman, W. T. [Department of Biology, University of New Mexico, Albuquerque NM USA; McDowell, N. [Earth Systems Analysis and Modeling, Pacific Northwest National Laboratory, Richland WA USA; Huang, C. -W. [Department of Biology, University of New Mexico, Albuquerque NM USA; Krofcheck, D. J. [Department of Biology, University of New Mexico, Albuquerque NM USA; Fox, A. M. [School of Natural Resources and the Environment, University of Arizona, Tucson AZ USA; Sinsabaugh, R. L. [Department of Biology, University of New Mexico, Albuquerque NM USA; Rahn, T. A. [Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos NM USA; Litvak, M. E. [Department of Biology, University of New Mexico, Albuquerque NM USA

2017-12-01

Climate-driven tree mortality has increased globally in response to warmer temperature and more severe drought. To examine how tree mortality in semi-arid biomes impacts surface water balance, we experimentally manipulated a piñon-juniper (PJ) woodland by girdling all adult piñon trees in a 4 ha area, decreasing piñon basal area by ~65%. Over 3.5 years (2009-2013), we compared water flux measurements from this girdled site with those from a nearby intact PJ woodland. Before and after girdling, the ratio of evapotranspiration (ET) to incoming precipitation was similar between the two sites. Girdling altered the partitioning of ET such that the contribution of canopy transpiration to ET decreased 9-14% over the study period, relative to the intact control, while non-canopy ET increased. We attributed the elevated non-canopy ET in the girdled site each year to winter increases in sublimation, and summer increases in both soil evaporation and below-canopy transpiration. Although we expected that mortality of a canopy dominant would increase the availability of water and other resources to surviving vegetation, we observed a decrease in both soil volumetric water content and sap flow rates in the remaining trees at the girdled site, relative to the control. This post-girdling decrease in the performance of the remaining trees occurred during the severe 2011-2012 drought, suggesting that piñon mortality may trigger feedback mechanisms that leave PJ woodlands drier relative to undisturbed sites, and potentially more vulnerable to drought.

Can Community Members Identify Tropical Tree Species for REDD+ Carbon and Biodiversity Measurements?

Science.gov (United States)

Zhao, Mingxu; Brofeldt, Søren; Li, Qiaohong; Xu, Jianchu; Danielsen, Finn; Læssøe, Simon Bjarke Lægaard; Poulsen, Michael Køie; Gottlieb, Anna; Maxwell, James Franklin; Theilade, Ida

2016-01-01

Biodiversity conservation is a required co-benefit of REDD+. Biodiversity monitoring is therefore needed, yet in most areas it will be constrained by limitations in the available human professional and financial resources. REDD+ programs that use forest plots for biomass monitoring may be able to take advantage of the same data for detecting changes in the tree diversity, using the richness and abundance of canopy trees as a proxy for biodiversity. If local community members are already assessing the above-ground biomass in a representative network of forest vegetation plots, it may require minimal further effort to collect data on the diversity of trees. We compare community members and trained scientists' data on tree diversity in permanent vegetation plots in montane forest in Yunnan, China. We show that local community members here can collect tree diversity data of comparable quality to trained botanists, at one third the cost. Without access to herbaria, identification guides or the Internet, community members could provide the ethno-taxonomical names for 95% of 1071 trees in 60 vegetation plots. Moreover, we show that the community-led survey spent 89% of the expenses at village level as opposed to 23% of funds in the monitoring by botanists. In participatory REDD+ programs in areas where community members demonstrate great knowledge of forest trees, community-based collection of tree diversity data can be a cost-effective approach for obtaining tree diversity information.

Can Community Members Identify Tropical Tree Species for REDD+ Carbon and Biodiversity Measurements?

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Mingxu Zhao

Full Text Available Biodiversity conservation is a required co-benefit of REDD+. Biodiversity monitoring is therefore needed, yet in most areas it will be constrained by limitations in the available human professional and financial resources. REDD+ programs that use forest plots for biomass monitoring may be able to take advantage of the same data for detecting changes in the tree diversity, using the richness and abundance of canopy trees as a proxy for biodiversity. If local community members are already assessing the above-ground biomass in a representative network of forest vegetation plots, it may require minimal further effort to collect data on the diversity of trees. We compare community members and trained scientists' data on tree diversity in permanent vegetation plots in montane forest in Yunnan, China. We show that local community members here can collect tree diversity data of comparable quality to trained botanists, at one third the cost. Without access to herbaria, identification guides or the Internet, community members could provide the ethno-taxonomical names for 95% of 1071 trees in 60 vegetation plots. Moreover, we show that the community-led survey spent 89% of the expenses at village level as opposed to 23% of funds in the monitoring by botanists. In participatory REDD+ programs in areas where community members demonstrate great knowledge of forest trees, community-based collection of tree diversity data can be a cost-effective approach for obtaining tree diversity information.

Carbon storage and sequestration by trees in urban and community areas of the United States

International Nuclear Information System (INIS)

Nowak, David J.; Greenfield, Eric J.; Hoehn, Robert E.; Lapoint, Elizabeth

2013-01-01

Carbon storage and sequestration by urban trees in the United States was quantified to assess the magnitude and role of urban forests in relation to climate change. Urban tree field data from 28 cities and 6 states were used to determine the average carbon density per unit of tree cover. These data were applied to statewide urban tree cover measurements to determine total urban forest carbon storage and annual sequestration by state and nationally. Urban whole tree carbon storage densities average 7.69 kg C m −2 of tree cover and sequestration densities average 0.28 kg C m −2 of tree cover per year. Total tree carbon storage in U.S. urban areas (c. 2005) is estimated at 643 million tonnes ($50.5 billion value; 95% CI = 597 million and 690 million tonnes) and annual sequestration is estimated at 25.6 million tonnes ($2.0 billion value; 95% CI = 23.7 million to 27.4 million tonnes). -- Highlights: •Total tree carbon storage in U.S. urban areas (c. 2005) is estimated at 643 million tonnes. •Total tree carbon storage in U.S. urban and community areas is estimated at 1.36 billion tonnes. •Net carbon sequestration in U.S. urban areas varies by state and is estimated at 18.9 million tonnes per year. •Overlap between U.S. forest and urban forest carbon estimates is between 247 million and 303 million tonnes. -- Field and tree cover measurements reveal carbon storage and sequestration by trees in U.S. urban and community areas

New York City's Children First: Lessons in School Reform

Science.gov (United States)

Kelleher, Maureen

2014-01-01

Under Mayor Michael Bloomberg, New York City's education system embarked on a massive change effort, known as Children First, that produced significant results: new and better school options for families, more college-ready graduates, and renewed public confidence in New York City's schools. New York City's reform effort has also produced…

Adult trees cause density-dependent mortality in conspecific seedlings by regulating the frequency of pathogenic soil fungi.

Science.gov (United States)

Liang, Minxia; Liu, Xubing; Gilbert, Gregory S; Zheng, Yi; Luo, Shan; Huang, Fengmin; Yu, Shixiao

2016-12-01

Negative density-dependent seedling mortality has been widely detected in tropical, subtropical and temperate forests, with soil pathogens as a major driver. Here we investigated how host density affects the composition of soil pathogen communities and consequently influences the strength of plant-soil feedbacks. In field censuses of six 1-ha permanent plots, we found that survival was much lower for newly germinated seedlings that were surrounded by more conspecific adults. The relative abundance of pathogenic fungi in soil increased with increasing conspecific tree density for five of nine tree species; more soil pathogens accumulated around roots where adult tree density was higher, and this greater pathogen frequency was associated with lower seedling survival. Our findings show how tree density influences populations of soil pathogens, which creates plant-soil feedbacks that contribute to community-level and population-level compensatory trends in seedling survival. © 2016 John Wiley & Sons Ltd/CNRS.

A population-based study examining the emergence of community-associated methicillin-resistant Staphylococcus aureus USA300 in New York City

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Panwar Monica

2006-11-01

Full Text Available Abstract Background Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA is a serious pathogen in several regions in the United States. It is unclear which populations are at high risk for the emergence of these strains. Methods All unique patient isolates of S. aureus were collected from hospitals in Brooklyn, NY over a three-month period. Isolates of MRSA that were susceptible to clindamycin underwent SCCmec typing. Isolates with the SCCmec type IV (characteristic of CA-MRSA strains underwent ribotyping. Demographic information involving the neighborhoods of Brooklyn was also gathered and correlated with the prevalence of CA-MRSA strains. Results Of 1316 isolates collected during the surveillance, 217 were MRSA susceptible to clindamycin. A total of 125 isolates possessed SCCmec type IV; 72 belonged to the USA300 strain and five belonged to the USA400 strain. Hospitals in the eastern part of the city had the highest prevalence of USA300 strain. Individuals in the eastern region, when compared to the western region, were more likely to be Black, Hispanic, female, and Conclusion The USA300 strain of CA-MRSA is emerging in New York City. In this population-based study, urban regions of lower socioeconomic status and with evidence of overcrowding appear to be at higher risk for the emergence of this pathogen.

Northern California coast community tree guide: benefits, costs, and strategic planting

Science.gov (United States)

E. Gregory McPherson; James R. Simpson; Paula. J. Peper; Aaron M.N. Crowell; Qingfu Xiao

2010-01-01

Trees make our cities more attractive and provide many ecosystem services, including air quality improvement, energy conservation, stormwater interception, and atmospheric carbon dioxide reduction. These benefits must be weighed against the costs of maintaining trees, including planting, pruning, irrigation, administration, pest control, liability, cleanup, and removal...

"Gray murder": characteristics of elderly compared with nonelderly homicide victims in New York City.

Science.gov (United States)

Abrams, Robert C; Leon, Andrew C; Tardiff, Kenneth; Marzuk, Peter M; Sutherland, Kari

2007-09-01

We compared characteristics of homicides among New York City residents aged 18 years and older from 1990 to 1998 to determine differences in demographics, cause and place of death, and presence of illicit drugs and alcohol in the deceased's system. All medical examiner-certified homicides among New York City residents aged 18 years and older from 1990 to 1998 were studied (n = 11,850). Nonelderly (aged 18 to 64 years) and elderly (aged 65 years and older) victims were compared by gender, race/ethnicity, cause of death, place of death, and presence of illicit drugs or alcohol. Population-based homicide rates stratified by age, gender, and race were also calculated. Nonelderly homicide victims were significantly more likely to be male, non-White, to have been shot in the city streets, and to have evidence of illicit drug or alcohol use. Elderly victims were more likely to be female, White, to have been killed by nonfirearm injuries, and to have been killed in their own homes. The gender and race differences between age groups remained but were attenuated when population-based rates were compared. The characteristics of homicide in nonelderly adults do not apply to elderly adults in New York City. Demographic factors and vulnerabilities of the elderly may underlie these differences, pointing to the need for oversight of isolated or homebound elderly persons and for protective interventions.

Community harvesting of trees used as dens and for food by the tree hyrax (Dendrohyrax arboreus in the Pirie forest, South Africa

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Elizabeth J. Opperman

2018-02-01

Full Text Available Forests in South Africa are harvested by local communities for multiple purposes and this affects the animals that inhabit them. The tree hyrax (Dendrohyrax arboreus has a restricted distribution and utilises various tree species as dens and a source of food. In this article, we determined, through a series of interviews in the communities surrounding the Pirie forest, which plant species are harvested by local people and whether these overlap with those used by the tree hyrax. In addition, we determined the extent to which tree hyraxes are hunted by these communities. Of the trees used by the hyrax as dens in the Pirie forest, Afrocarpus falcatus, Schotia latifolia, Andrachne ovalis, Teclea natalensis and Apodytes dimidiata are important resources for local communities. But as these are harvested at relatively low levels, it is unlikely that current harvesting has a large impact on the tree hyrax. Opportunistic hunting occurs, but the hyrax is not targeted by hunters. Very limited commercial harvesting of A. falcatus has been taking place in the Pirie forest since 1975, but its impact on the hyrax population, although undetermined, is also unlikely to be high. We recommend that the Pirie forest tree hyrax population should be monitored by forest management in order to ascertain the impact of both commercial and community harvesting over the past quarter-century. Conservation implications: Tree hyrax populations in the Pirie forest should be actively monitored by management on an annual basis.

TREE CANOPY COVER MAPPING USING LiDAR IN URBAN BARANGAYS OF CEBU CITY, CENTRAL PHILIPPINES

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J. A. Ejares

2016-06-01

Full Text Available This paper investigates tree canopy cover mapping of urban barangays (smallest administrative division in the Philippines in Cebu City using LiDAR (Light Detection and Ranging. Object-Based Image Analysis (OBIA was used to extract tree canopy cover. Multi-resolution segmentation and a series of assign-class algorithm in eCognition software was also performed to extract different land features. Contextual features of tree canopies such as height, area, roundness, slope, length-width and elliptic fit were also evaluated. The results showed that at the time the LiDAR data was collected (June 24, 2014, the tree cover was around 25.11 % (or 15,674,341.8 m2 of the city’s urban barangays (or 62,426,064.6 m2. Among all urban barangays in Cebu City, Barangay Busay had the highest cover (55.79 % while barangay Suba had the lowest (0.8 %. The 16 barangays with less than 10 % tree cover were generally located in the coastal area, presumably due to accelerated urbanization. Thirty-one barangays have tree cover ranging from 10.59–-27.3 %. Only 3 barangays (i.e., Lahug, Talamban, and Busay have tree cover greater than 30 %. The overall accuracy of the analysis was 96.6 % with the Kappa Index of Agreement or KIA of 0.9. From the study, a grouping can be made of the city’s urban barangays with regards to tree cover. The grouping will be useful to urban planners not only in allocating budget to the tree planting program of the city but also in planning and creation of urban parks and playgrounds.

Tree mortality from fires, bark beetles, and timber harvest during a hot and dry decade in the western United States (2003-2012)

Science.gov (United States)

Berner, Logan T.; Law, Beverly E.; Meddens, Arjan J. H.; Hicke, Jeffrey A.

2017-06-01

High temperatures and severe drought contributed to extensive tree mortality from fires and bark beetles during the 2000s in parts of the western continental United States. Several states in this region have greenhouse gas (GHG) emission targets and would benefit from information on the amount of carbon stored in tree biomass killed by disturbance. We quantified mean annual tree mortality from fires, bark beetles, and timber harvest from 2003-2012 for each state in this region. We estimated tree mortality from fires and beetles using tree aboveground carbon (AGC) stock and disturbance data sets derived largely from remote sensing. We quantified tree mortality from harvest using data from US Forest Service reports. In both cases, we used Monte Carlo analyses to track uncertainty associated with parameter error and temporal variability. Regional tree mortality from harvest, beetles, and fires (MORTH+B+F) together averaged 45.8 ± 16.0 Tg AGC yr-1 (±95% confidence interval), indicating a mortality rate of 1.10 ± 0.38% yr-1. Harvest accounted for the largest percentage of MORTH+B+F (˜50%), followed by beetles (˜32%), and fires (˜18%). Tree mortality from harvest was concentrated in Washington and Oregon, where harvest accounted for ˜80% of MORTH+B+F in each state. Tree mortality from beetles occurred widely at low levels across the region, yet beetles had pronounced impacts in Colorado and Montana, where they accounted for ˜80% of MORTH+B+F. Tree mortality from fires was highest in California, though fires accounted for the largest percentage of MORTH+B+F in Arizona and New Mexico (˜50%). Drought and human activities shaped regional variation in tree mortality, highlighting opportunities and challenges to managing GHG emissions from forests. Rising temperatures and greater risk of drought will likely increase tree mortality from fires and bark beetles during coming decades in this region. Thus, sustained monitoring and mapping of tree mortality is necessary to

Cancer Mortality among Asians and Pacific Islanders in New York City, 2001–2010

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Vivian Huang

2013-01-01

Full Text Available Asians and Pacific Islanders’ (APIs leading cause of death is cancer. We compared APIs’ age-adjusted cancer mortality rates to other racial/ethnic groups and by API subgroup (i.e., Chinese, Koreans, Asian Indians, and Filipinos using New York City (NYC Mortality data and Census Bureau population estimates for 2001–2010. While other racial/ethnic groups’ overall cancer mortality rates declined in NYC during the last decade, APIs remained stable. APIs overall had the lowest mortality rates for more common cancer types (i.e., lung, colorectal, breast, and prostate, but the highest mortality rates for certain less common cancers (i.e., nasopharyngeal, stomach, and liver. Chinese New Yorkers’ lung cancer death rates were very high compared to other APIs and comparable to non-Hispanic whites (47.1/100,000 versus 49.5/100,000, resp.. Chinese men had much higher nasopharyngeal cancer mortality rates (4.5/100,000 versus 0.3/100,000 for non-Hispanic whites. Korean men had the highest liver and stomach cancer mortality rates (25.3/100,000 and 27.7/100,000, resp., versus 7.9/100,000 and 6.0/100,000 for non-Hispanic whites. Analysis of cancer rates by API subgroup provides the detailed information needed to plan cancer prevention efforts. These findings warrant consideration of targeted cancer mortality prevention efforts for affected subgroups, including hepatitis vaccination, screening, and treatment; smoking cessation; and cancer screening.

Tree Species Identity Shapes Earthworm Communities

DEFF Research Database (Denmark)

Schelfhout, Stephanie; Mertens, Jan; Verheyen, Kris

2017-01-01

Earthworms are key organisms in forest ecosystems because they incorporate organic material into the soil and affect the activity of other soil organisms. Here, we investigated how tree species affect earthworm communities via litter and soil characteristics. In a 36-year old common garden...... of soil and foliar litter, and determined the forest floor turnover rate and the density and biomass of the earthworm species occurring in the stands. Tree species significantly affected earthworm communities via leaf litter and/or soil characteristics. Anecic earthworms were abundant under Fraxinus, Acer...

Million trees Los Angeles canopy cover and benefit assessment

Science.gov (United States)

E.G. McPherson; J.R. Simpson; Q. Xiao; C. Wu

2011-01-01

The Million Trees LA initiative intends to improve Los Angeles’s environment through planting and stewardship of 1 million trees. The purpose of this study was to measure Los Angeles’s existing tree canopy cover (TCC), determine if space exists for 1 million additional trees, and estimate future benefits from the planting. High-resolution QuickBird remote sensing data...

The structure of spruce-fir tree stands mortality under impact of the Middle Ural copper smelter emissions

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I. E. Bergman

2015-04-01

Full Text Available The influence of industrial pollution on mortality values (dead fallen wood and dead standing trees and its distribution by degrees of decomposition were investigated in spruce-fir forest stands in the vicinity of the Middle Ural copper smelter (the city of Revda, Sverdlovsk region. The total mortality and mortality in each size category did not depend on the distance to the source of pollution. At the same time, the amount of dead fallen wood was significantly greater (1.9 times in the polluted area (2 and 4 km from the smelter as compared with the background territory (30 km from the smelter. Mortality proportion out of the total number of the trees (both live and dead did not differ significantly between the sites, although this parameter tended to increase nearer the smelter. The distribution of mortality by size categories revealed significant differences between background territory and site with average level of contamination, as well as background territory and highly contaminated site. Observed differences are associated with an increased proportion of lesser mortality near the smelter (by 15 % and 12 % as compared with areas of background and middle levels of contamination, respectively, as well as because of double-declining of medium- and large-sized mortality near the smelter. The distribution of the living tree stands by size categories also has a connection with level of contamination. The average diameters of the living tree stand and the elements of coarse woody debris (dead fallen wood and dead standing trees do not differ significantly between sites with different levels of contamination. For the small-sized dead fallen wood, the proportion of weakly decomposed stems increased with the level of pollution, while proportion of strongly decomposed stems decreased. The distribution of medium- and large-sized dead fallen wood on the stages of decomposition does not vary between sites with different levels of pollution.

INDIGENOUS COMMUNITY TREE INVENTORY: ASSESSMENT OF DATA QUALITY

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M. F. Fauzi

2016-09-01

Full Text Available The citizen science program to supplement authoritative data in tree inventory has been well implemented in various countries. However, there is a lack of study that assesses correctness and accuracy of tree data supplied by citizens. This paper addresses the issue of tree data quality supplied by semi-literate indigenous group. The aim of this paper is to assess the correctness of attributes (tree species name, height and diameter at breast height and the accuracy of tree horizontal positioning data supplied by indigenous people. The accuracy of the tree horizontal position recorded by GNSS-enable smart phone was found to have a RMSE value of ± 8m which is not suitable to accurately locate individual tree position in tropical rainforest such as the Royal Belum State Park. Consequently, the tree species names contributed by indigenous people were only 20 to 30 percent correct as compared with the reference data. However, the combination of indigenous respondents comprising of different ages, experience and knowledge working in a group influence less attribute error in data entry and increase the use of free text rather than audio methods. The indigenous community has a big potential to engage with scientific study due to their local knowledge with the research area, however intensive training must be given to empower their skills and several challenges need to be addressed.

A global overview of drought and heat-induced tree mortality reveals emerging climate change risks for forests

Science.gov (United States)

Allen, Craig D.; Macalady, A.K.; Chenchouni, H.; Bachelet, D.; McDowell, N.; Vennetier, Michel; Kitzberger, T.; Rigling, A.; Breshears, D.D.; Hogg, E.H.(T.); Gonzalez, P.; Fensham, R.; Zhang, Z.; Castro, J.; Demidova, N.; Lim, J.-H.; Allard, G.; Running, S.W.; Semerci, A.; Cobb, N.

2010-01-01

Greenhouse gas emissions have significantly altered global climate, and will continue to do so in the future. Increases in the frequency, duration, and/or severity of drought and heat stress associated with climate change could fundamentally alter the composition, structure, and biogeography of forests in many regions. Of particular concern are potential increases in tree mortality associated with climate-induced physiological stress and interactions with other climate-mediated processes such as insect outbreaks and wildfire. Despite this risk, existing projections of tree mortality are based on models that lack functionally realistic mortality mechanisms, and there has been no attempt to track observations of climate-driven tree mortality globally. Here we present the first global assessment of recent tree mortality attributed to drought and heat stress. Although episodic mortality occurs in the absence of climate change, studies compiled here suggest that at least some of the world's forested ecosystems already may be responding to climate change and raise concern that forests may become increasingly vulnerable to higher background tree mortality rates and die-off in response to future warming and drought, even in environments that are not normally considered water-limited. This further suggests risks to ecosystem services, including the loss of sequestered forest carbon and associated atmospheric feedbacks. Our review also identifies key information gaps and scientific uncertainties that currently hinder our ability to predict tree mortality in response to climate change and emphasizes the need for a globally coordinated observation system. Overall, our review reveals the potential for amplified tree mortality due to drought and heat in forests worldwide.

Factors that influence Christmas tree sales

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Thomas H. Pendleton; Lawrence D. Garrett

1970-01-01

An analysis of the metropolitan Christmas tree market in Winston-Salem, N. C., shows that to sell more trees, Christmas tree retailers should locate their lots on heavily traveled streets in business areas, have adequate parking facilities, advertise, and have attractive displays of trees. Retailers who follow these practices can expect to receive higher prices for...

New York: Multi-Speak City!

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New York City Economic Development Council, NY.

This guide was written to help teachers make students aware of the multilingual and multi-ethnic nature of New York City in order to experience and explore different languages and customs. New York is a center for variety in language and culture in the areas of diplomacy, international commerce, media and communications, foods and fashion, the…

The Influence of Vegetation Function towards the Langsep Street Thermal Comfort

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Alfian, R.; Setyabudi, I.; Uran, R. S.

2017-10-01

Streetscape is an important element for character building of the environment, spatial, and visual in order to provide an urban identity, especially in Malang City protocol streets. Langsep Street is one of the protocol streets in Malang City. Langsep Street famous with central education and offices area. This study aims (1) to identify vegetation of streetscape; (2) to analyze the thermal comfort of the streetscape, and (3) to evaluate the comfort level of Langsep Street. The method used was the THI approach. THI value that obtained was analyzed using the standard of Laurie (1990). Based on observations, the THI value of Langsep Street was 27.60. This was influenced by the trees canopy density and spacing of the trees on the streetscape. It can be concluded that streetscape required (1) shaded plants that have root systems that do not damage the construction of roads, (2) the branching plants are not easily broken and easy to maintain, and (3) the combination of trees, shrubs and ground cover.

Predicting the probability of mortality of gastric cancer patients using decision tree.

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Mohammadzadeh, F; Noorkojuri, H; Pourhoseingholi, M A; Saadat, S; Baghestani, A R

2015-06-01

Gastric cancer is the fourth most common cancer worldwide. This reason motivated us to investigate and introduce gastric cancer risk factors utilizing statistical methods. The aim of this study was to identify the most important factors influencing the mortality of patients who suffer from gastric cancer disease and to introduce a classification approach according to decision tree model for predicting the probability of mortality from this disease. Data on 216 patients with gastric cancer, who were registered in Taleghani hospital in Tehran,Iran, were analyzed. At first, patients were divided into two groups: the dead and alive. Then, to fit decision tree model to our data, we randomly selected 20% of dataset to the test sample and remaining dataset considered as the training sample. Finally, the validity of the model examined with sensitivity, specificity, diagnosis accuracy and the area under the receiver operating characteristic curve. The CART version 6.0 and SPSS version 19.0 softwares were used for the analysis of the data. Diabetes, ethnicity, tobacco, tumor size, surgery, pathologic stage, age at diagnosis, exposure to chemical weapons and alcohol consumption were determined as effective factors on mortality of gastric cancer. The sensitivity, specificity and accuracy of decision tree were 0.72, 0.75 and 0.74 respectively. The indices of sensitivity, specificity and accuracy represented that the decision tree model has acceptable accuracy to prediction the probability of mortality in gastric cancer patients. So a simple decision tree consisted of factors affecting on mortality of gastric cancer may help clinicians as a reliable and practical tool to predict the probability of mortality in these patients.

Detecting Drought-Induced Tree Mortality in Sierra Nevada Forests with Time Series of Satellite Data

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Sarah Byer

2017-09-01

Full Text Available A five-year drought in California led to a significant increase in tree mortality in the Sierra Nevada forests from 2012 to 2016. Landscape level monitoring of forest health and tree dieback is critical for vegetation and disaster management strategies. We examined the capability of multispectral imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS in detecting and explaining the impacts of the recent severe drought in Sierra Nevada forests. Remote sensing metrics were developed to represent baseline forest health conditions and drought stress using time series of MODIS vegetation indices (VIs and a water index. We used Random Forest algorithms, trained with forest aerial detection surveys data, to detect tree mortality based on the remote sensing metrics and topographical variables. Map estimates of tree mortality demonstrated that our two-stage Random Forest models were capable of detecting the spatial patterns and severity of tree mortality, with an overall producer’s accuracy of 96.3% for the classification Random Forest (CRF and a RMSE of 7.19 dead trees per acre for the regression Random Forest (RRF. The overall omission errors of the CRF ranged from 19% for the severe mortality class to 27% for the low mortality class. Interpretations of the models revealed that forests with higher productivity preceding the onset of drought were more vulnerable to drought stress and, consequently, more likely to experience tree mortality. This method highlights the importance of incorporating baseline forest health data and measurements of drought stress in understanding forest response to severe drought.

Tree Species Identity Shapes Earthworm Communities

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Stephanie Schelfhout

2017-03-01

Full Text Available Earthworms are key organisms in forest ecosystems because they incorporate organic material into the soil and affect the activity of other soil organisms. Here, we investigated how tree species affect earthworm communities via litter and soil characteristics. In a 36-year old common garden experiment, replicated six times over Denmark, six tree species were planted in blocks: sycamore maple (Acer pseudoplatanus, beech (Fagus sylvatica, ash (Fraxinus excelsior, Norway spruce (Picea abies, pedunculate oak (Quercus robur and lime (Tilia cordata. We studied the chemical characteristics of soil and foliar litter, and determined the forest floor turnover rate and the density and biomass of the earthworm species occurring in the stands. Tree species significantly affected earthworm communities via leaf litter and/or soil characteristics. Anecic earthworms were abundant under Fraxinus, Acer and Tilia, which is related to calcium-rich litter and low soil acidification. Epigeic earthworms were indifferent to calcium content in leaf litter and were shown to be mainly related to soil moisture content and litter C:P ratios. Almost no earthworms were found in Picea stands, likely because of the combined effects of recalcitrant litter, low pH and low soil moisture content.

Influence of matrix type on tree community assemblages along tropical dry forest edges.

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Benítez-Malvido, Julieta; Gallardo-Vásquez, Julio César; Alvarez-Añorve, Mariana Y; Avila-Cabadilla, Luis Daniel

2014-05-01

• Anthropogenic habitat edges have strong negative consequences for the functioning of tropical ecosystems. However, edge effects on tropical dry forest tree communities have been barely documented.• In Chamela, Mexico, we investigated the phylogenetic composition and structure of tree assemblages (≥5 cm dbh) along edges abutting different matrices: (1) disturbed vegetation with cattle, (2) pastures with cattle and, (3) pastures without cattle. Additionally, we sampled preserved forest interiors.• All edge types exhibited similar tree density, basal area and diversity to interior forests, but differed in species composition. A nonmetric multidimensional scaling ordination showed that the presence of cattle influenced species composition more strongly than the vegetation structure of the matrix; tree assemblages abutting matrices with cattle had lower scores in the ordination. The phylogenetic composition of tree assemblages followed the same pattern. The principal plant families and genera were associated according to disturbance regimes as follows: pastures and disturbed vegetation (1) with cattle and (2) without cattle, and (3) pastures without cattle and interior forests. All habitats showed random phylogenetic structures, suggesting that tree communities are assembled mainly by stochastic processes. Long-lived species persisting after edge creation could have important implications in the phylogenetic structure of tree assemblages.• Edge creation exerts a stronger influence on TDF vegetation pathways than previously documented, leading to new ecological communities. Phylogenetic analysis may, however, be needed to detect such changes. © 2014 Botanical Society of America, Inc.

The Effect of Tree Spacing and Size in Urban Areas: Strategies for Mitigating High Temperature in Urban Heat Islands

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Berry, R.; Shandas, V.; Makido, Y.

2017-12-01

Many cities are unintentionally designed to be heat sinks, which absorb the sun's short-wave radiation and reemit as long-wave radiation. Long time reorganization of this `urban heat island' (UHI) phenomena has led researchers and city planners into developing strategies for reducing ambient temperatures through urban design. Specifically, greening areas have proven to reduce the temperature in UHI's, including strategies such as green streets, green facades, and green roofs have been implemented. Among the scientific community there is promoted study of how myriad greening strategies can reduce temperature, relatively limited work has focused on the distribution, density, and quantity of tree campaigns. This paper examines how the spacing and size of trees reduce temperatures differently. A major focus of the paper is to understand how to lower the temperature through tree planting, and provide recommendations to cities that are attempting to solve their own urban heat island issues. Because different cities have different room for planting greenery, we examined which strategies are more efficient given an area constraint. Areas that have less available room might not be able to plant a high density of trees. We compared the different experimental groups varying in density and size of trees against the control to see the effect the trees had. Through calibration with local weather stations, we used a micrometeorology program (ENVI-Met) to model and simulate the different experimental models and how they affect the temperature. The results suggest that some urban designs can reduce ambient temperatures by over 7 0C, and the inclusion of large form trees have the greatest contribution, by reducing temperatures over 15 0C. The results suggest that using specific strategies that combine placement of specific tree configurations with alternative distribution of urban development patterns can help to solve the current challenges of UHI's, and thereby support management

Detecting early warning signals of tree mortality in boreal North America using multiscale satellite data.

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Rogers, Brendan M; Solvik, Kylen; Hogg, Edward H; Ju, Junchang; Masek, Jeffrey G; Michaelian, Michael; Berner, Logan T; Goetz, Scott J

2018-02-26

Increasing tree mortality from global change drivers such as drought and biotic infestations is a widespread phenomenon, including in the boreal zone where climate changes and feedbacks to the Earth system are relatively large. Despite the importance for science and management communities, our ability to forecast tree mortality at landscape to continental scales is limited. However, two independent information streams have the potential to inform and improve mortality forecasts: repeat forest inventories and satellite remote sensing. Time series of tree-level growth patterns indicate that productivity declines and related temporal dynamics often precede mortality years to decades before death. Plot-level productivity, in turn, has been related to satellite-based indices such as the Normalized difference vegetation index (NDVI). Here we link these two data sources to show that early warning signals of mortality are evident in several NDVI-based metrics up to 24 years before death. We focus on two repeat forest inventories and three NDVI products across western boreal North America where productivity and mortality dynamics are influenced by periodic drought. These data sources capture a range of forest conditions and spatial resolution to highlight the sensitivity and limitations of our approach. Overall, results indicate potential to use satellite NDVI for early warning signals of mortality. Relationships are broadly consistent across inventories, species, and spatial resolutions, although the utility of coarse-scale imagery in the heterogeneous aspen parkland was limited. Longer-term NDVI data and annually remeasured sites with high mortality levels generate the strongest signals, although we still found robust relationships at sites remeasured at a typical 5 year frequency. The approach and relationships developed here can be used as a basis for improving forest mortality models and monitoring systems. © 2018 John Wiley & Sons Ltd.

Evaluating methods to detect bark beetle-caused tree mortality using single-date and multi-date Landsat imagery

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Arjan J. H. Meddens; Jeffrey A. Hicke; Lee A. Vierling; Andrew T. Hudak

2013-01-01

Bark beetles cause significant tree mortality in coniferous forests across North America. Mapping beetle-caused tree mortality is therefore important for gauging impacts to forest ecosystems and assessing trends. Remote sensing offers the potential for accurate, repeatable estimates of tree mortality in outbreak areas. With the advancement of multi-temporal disturbance...

Dispersion of traffic exhausts in urban street canyons with tree plantings : experimental and numerical investigations

NARCIS (Netherlands)

Gromke, C.B.; Denev, J.; Ruck, B.

2007-01-01

Wind tunnel experiments and numerical computations have been performed in order to investigate the influence of avenuelike tree plantings on the dispersion of traffic exhaust in an urban street canyon. Reduced natural ventilation and enhanced pollutant concentrations have been found in the presence

Risk factors associated with sexually transmitted infections among women under community supervision in New York City.

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Davis, Alissa; Goddard-Eckrich, Dawn; Dasgupta, Anindita; El-Bassel, Nabila

2018-01-01

The number of women under community supervision in the United States has increased, and this population has a high risk for sexually transmitted infections (STIs). We examined STI prevalence and multiple risk factors among drug-involved women under community supervision in New York City. Data were from a randomized controlled trial testing the efficacy of a behavioral HIV/STI intervention (Women on the Road to Health [WORTH]) among drug-involved women in the community corrections system in New York City from 2009 to 2012. To be eligible for inclusion, women had to be under community supervision within the past 90 days, have used illicit drugs at least once in the past six months, and have unprotected sex at least once in the past 90 days. Participants completed a survey containing items on STI risk factors and were tested for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis. Multivariable regression was used to examine associations between risk factors and STI diagnosis. Of 333 women tested, 89 (26.7%) tested positive for an STI. Ten (3.0%) were positive for C. trachomatis, 4 (1.2%) for N. gonorrhoeae, and 77 (23.1%) for T. vaginalis. Women with any STI were more likely to be black (AOR: 2.02; 95% CI: 1.08-3.77), homeless in the past 90 days (AOR: 2.07; 95% CI: 1.01-4.26), arrested in the past 90 days (AOR: 1.97; 95% CI: 1.14-3.39), and have a greater number of sexual partners in the past 90 days (AOR: 1.24; 95% CI: 1.08-1.42). Drug-using women under community supervision have a high burden of STIs driven by multiple risk factors. Implementing STI screening, prevention, and treatment programs in community supervision settings could facilitate a reduction in STIs among this population.

Analysis and out-year forecast of beetle, borer, and drought-induced tree mortality in California

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Haiganoush K. Preisler; Nancy E. Grulke; Zachary Heath; Sheri L. Smith

2017-01-01

The level of tree mortality and drought observed over the past decade in North America has been described as ‘unparalleled’ in our modern history, in particular in the Sierra Nevada, California. Forest managers could use early warning of where and how much tree mortality to expect in the very near future to plan and prioritize hazard tree removal, pest suppression...

Effects of acidic deposition and soil acidification on sugar maple trees in the Adirondack Mountains, New York

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Sullivan, Timothy J.; Lawrence, Gregory B.; Bailey, Scott W.; McDonnell, Todd C.; McPherson, G.T.

2013-01-01

This study documents the effects of acidic deposition and soil acid-base chemistry on the growth, regeneration, and canopy condition of sugar maple (SM) trees in the Adirondack Mountains of New York. Sugar maple is the dominant canopy species throughout much of the northern hardwood forest in the State. A field study was conducted in 2009 in which 50 study plots within 20 small Adirondack watersheds were sampled and evaluated for soil acid-base chemistry and SM growth, canopy condition, and regeneration. Atmospheric sulfur (S) and nitrogen (N) deposition were estimated for each plot. Trees growing on soils with poor acid-base chemistry (low exchangeable calcium and % base saturation) that receive relatively high levels of atmospheric S and N deposition exhibited little to no SM seedling regeneration, decreased canopy condition, and short-to long-term growth declines compared with study plots having better soil condition and lower levels of atmospheric deposition. These results suggest that the ecosystem services provided by SM in the western and central Adirondack Mountain region, including aesthetic, cultural, and monetary values, are at risk from ongoing soil acidification caused in large part by acidic deposition.

How mammalian predation contributes to tropical tree community structure.

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Paine, C E Timothy; Beck, Harald; Terborgh, John

2016-12-01

The recruitment of seedlings from seeds is the key demographic transition for rain forest trees. Though tropical forest mammals are known to consume many seeds, their effects on tree community structure remain little known. To evaluate their effects, we monitored 8,000 seeds of 24 tree species using exclosure cages that were selectively permeable to three size classes of mammals for up to 4.4 years. Small and medium-bodied mammals removed many more seeds than did large mammals, and they alone generated beta diversity and negative density dependence, whereas all mammals reduced diversity and shaped local species composition. Thus, small and medium-bodied mammals more strongly contributed to community structure and promoted species coexistence than did large mammals. Given that seedling recruitment is seed limited for most species, alterations to the composition of the community of mammalian seed predators is expected to have long-term consequences for tree community structure in tropical forests. © 2016 by the Ecological Society of America.

Widespread crown condition decline, food web disruption, and amplified tree mortality with increased climate change-type drought.

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Carnicer, Jofre; Coll, Marta; Ninyerola, Miquel; Pons, Xavier; Sánchez, Gerardo; Peñuelas, Josep

2011-01-25

Climate change is progressively increasing severe drought events in the Northern Hemisphere, causing regional tree die-off events and contributing to the global reduction of the carbon sink efficiency of forests. There is a critical lack of integrated community-wide assessments of drought-induced responses in forests at the macroecological scale, including defoliation, mortality, and food web responses. Here we report a generalized increase in crown defoliation in southern European forests occurring during 1987-2007. Forest tree species have consistently and significantly altered their crown leaf structures, with increased percentages of defoliation in the drier parts of their distributions in response to increased water deficit. We assessed the demographic responses of trees associated with increased defoliation in southern European forests, specifically in the Iberian Peninsula region. We found that defoliation trends are paralleled by significant increases in tree mortality rates in drier areas that are related to tree density and temperature effects. Furthermore, we show that severe drought impacts are associated with sudden changes in insect and fungal defoliation dynamics, creating long-term disruptive effects of drought on food webs. Our results reveal a complex geographical mosaic of species-specific responses to climate change-driven drought pressures on the Iberian Peninsula, with an overwhelmingly predominant trend toward increased drought damage.

Tree mortality from a short-duration freezing event and global-change-type drought in a Southwestern piñon-juniper woodland, USA.

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Poulos, Helen M

2014-01-01

This study documents tree mortality in Big Bend National Park in Texas in response to the most acute one-year drought on record, which occurred following a five-day winter freeze. I estimated changes in forest stand structure and species composition due to freezing and drought in the Chisos Mountains of Big Bend National Park using permanent monitoring plot data. The drought killed over half (63%) of the sampled trees over the entire elevation gradient. Significant mortality occurred in trees up to 20 cm diameter (P Quercus emoryi Leibmann also experienced significant declines in tree density (P < 0.02) (30.9% and 20.7%, respectively). Subsequent droughts under climate change will likely cause even greater damage to trees that survived this record drought, especially if such events follow freezes. The results from this study highlight the vulnerability of trees in the Southwest to climatic change and that future shifts in forest structure can have large-scale community consequences.

Mexican and Cuban Composers in New York City circa 1880-1920

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John Koegel

2006-10-01

Full Text Available Cuban musicians active in New  York in the 1860s through the 1890s such as Ignacio Cervantes, Emilio Agramonte, and Rosalia Chalia assisted in the struggle for Cuban independence from Spain from the vantage point of New York's Cuban émigré community, and they also established  a strong  presence in the city's musical life.  Important Mexican musicians such as Miguel Lerdo  de Tejada and Carlos Curti intermittently visited New York or were long-term residents there. This was especially true during the late- nineteenth century, when the forced political stability during the Porfiriato made possible the extended visits of Mexican musicians and ensembles to North American cities such as New York. The Mexican Revolution also sent Mexican musicians to the United States in search of political freedom as well as economic and artistic opportunities that were temporarily closed to them in Mexico.

Design prototype detection tools of Porous Tree using microcontroller Arduino Uno R3 and piezoelectric sensor

Science.gov (United States)

Sujadi, H.; Bastian, A.; Tira

2018-05-01

In the city, many trees are found uprooted and cause accidents and many losses. No exception in the area of Majalengka Regency of West Java Province which can also anytime an accident or disaster caused by fallen trees, where in Majalengka district is logging trees on the street and public places are not done regularly. Based on the above problems, the need for tools that can detect a porous tree, to assist in the sorting of trees which should be felled and not felled by the party who has the authority of the general management of BMCK. Previously created tools to detect porous trees imported from Hungary and Germany, namely Arbosonic3D and Sonic Tomography. This design uses piezoelectric sensors to detect how much pressure is received by fragile and fragile trees, of course the fragile and fragile strength of trees will be different when exposed to the same pressure given the fragile density of fragile and fragile trees, then the data sent to Arduino Uno R3 to be processed into an information. This research produces a means of detecting the loss of a tree for early detection and no falling trees.

Tree mortality in the eastern Mediterranean, causes and implications under climatic change

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Sarris, Dimitrios; Iacovou, Valentina; Hoch, Guenter; Vennetier, Michel; Siegwolf, Rolf; Christodoulakis, Dimitrios; Koerner, Christian

2015-04-01

The eastern Mediterranean has experienced repeated incidents of forest mortality related to drought in recent decades. Such events may become more frequent in the future as drought conditions are projected to further intensify due to global warming. We have been investigating the causes behind such forest mortality events in Pinus halepensis, (the most drought tolerant pine in the Mediterranean). We cored tree stems and sampled various tissue types from dry habitats close to sea level and explored growth responses, stable isotope signals and non-structural carbohydrate (NSC) concentrations. Under intense drought that coincided with pine desiccation events in natural populations our result indicate a significant reduction in tree growth, the most significant in more than a century despite the increase in atmospheric CO2 concentrations in recent decades. This has been accompanied by a lengthening in the integration periods of rainfall needed for pine growth, reaching even 5-6 years before and including the year of mortality occurrence. Oxygen stable isotopes indicate that these signals were associated with a shift in tree water utilization from deeper moisture pools related to past rainfall events. Furthermore, where the driest conditions occur, pine carbon reserves were found to increase in stem tissue, indicating that mortality in these pines cannot be explained by carbon starvation. Our findings suggest that for pine populations that are already water limited (i) a further atmospheric CO2 increase will not compensate for the reduction in growth because of a drier climate, (ii) hydraulic failure appears as the most likely cause of pine desiccation, as no shortage occurs in tree carbon reserves, (iii) a further increase in mortality events may cause these systems to become carbon sources.

Categorizing ideas about trees: a tree of trees.

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Fisler, Marie; Lecointre, Guillaume

2013-01-01

The aim of this study is to explore whether matrices and MP trees used to produce systematic categories of organisms could be useful to produce categories of ideas in history of science. We study the history of the use of trees in systematics to represent the diversity of life from 1766 to 1991. We apply to those ideas a method inspired from coding homologous parts of organisms. We discretize conceptual parts of ideas, writings and drawings about trees contained in 41 main writings; we detect shared parts among authors and code them into a 91-characters matrix and use a tree representation to show who shares what with whom. In other words, we propose a hierarchical representation of the shared ideas about trees among authors: this produces a "tree of trees." Then, we categorize schools of tree-representations. Classical schools like "cladists" and "pheneticists" are recovered but others are not: "gradists" are separated into two blocks, one of them being called here "grade theoreticians." We propose new interesting categories like the "buffonian school," the "metaphoricians," and those using "strictly genealogical classifications." We consider that networks are not useful to represent shared ideas at the present step of the study. A cladogram is made for showing who is sharing what with whom, but also heterobathmy and homoplasy of characters. The present cladogram is not modelling processes of transmission of ideas about trees, and here it is mostly used to test for proximity of ideas of the same age and for categorization.

Within city limits: nature and children's books about nature in the city

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Leonard S. Marcus

1977-01-01

Many children's books give the impression that we must leave the city to be "in nature.'' This is a review of children's books about nature found within city limits. The books include a natural history of New York City; a guide to city wildflowers and other weeds; a book about city trees; a delightful inquiry into the true nature of the roach;...

Woodland recovery following drought-induced tree mortality across an environmental stress gradient.

Science.gov (United States)

Redmond, Miranda D; Cobb, Neil S; Clifford, Michael J; Barger, Nichole N

2015-10-01

Recent droughts and increasing temperatures have resulted in extensive tree mortality across the globe. Understanding the environmental controls on tree regeneration following these drought events will allow for better predictions of how these ecosystems may shift under a warmer, drier climate. Within the widely distributed piñon-juniper woodlands of the southwestern USA, a multiyear drought in 2002-2004 resulted in extensive adult piñon mortality and shifted adult woodland composition to a juniper-dominated, more savannah-type ecosystem. Here, we used pre- (1998-2001) and 10-year post- (2014) drought stand structure data of individually mapped trees at 42 sites to assess the effects of this drought on tree regeneration across a gradient of environmental stress. We found declines in piñon juvenile densities since the multiyear drought due to limited new recruitment and high (>50%) juvenile mortality. This is in contrast to juniper juvenile densities, which increased over this time period. Across the landscape, piñon recruitment was positively associated with live adult piñon densities and soil available water capacity, likely due to their respective effects on seed and water availability. Juvenile piñon survival was strongly facilitated by certain types of nurse trees and shrubs. These nurse plants also moderated the effects of environmental stress on piñon survival: Survival of interspace piñon juveniles was positively associated with soil available water capacity, whereas survival of nursed piñon juveniles was negatively associated with perennial grass cover. Thus, nurse plants had a greater facilitative effect on survival at sites with higher soil available water capacity and perennial grass cover. Notably, mean annual climatic water deficit and elevation were not associated with piñon recruitment or survival across the landscape. Our findings reveal a clear shift in successional trajectories toward a more juniper-dominated woodland and highlight the

Tree mortality from a short-duration freezing event and global-change-type drought in a Southwestern piñon-juniper woodland, USA

Directory of Open Access Journals (Sweden)

Helen M. Poulos

2014-06-01

Full Text Available This study documents tree mortality in Big Bend National Park in Texas in response to the most acute one-year drought on record, which occurred following a five-day winter freeze. I estimated changes in forest stand structure and species composition due to freezing and drought in the Chisos Mountains of Big Bend National Park using permanent monitoring plot data. The drought killed over half (63% of the sampled trees over the entire elevation gradient. Significant mortality occurred in trees up to 20 cm diameter (P < 0.05. Pinus cembroides Zucc. experienced the highest seedling and tree mortality (P < 0.0001 (55% of piñon pines died, and over five times as many standing dead pines were observed in 2012 than in 2009. Juniperus deppeana vonSteudal and Quercus emoryi Leibmann also experienced significant declines in tree density (P < 0.02 (30.9% and 20.7%, respectively. Subsequent droughts under climate change will likely cause even greater damage to trees that survived this record drought, especially if such events follow freezes. The results from this study highlight the vulnerability of trees in the Southwest to climatic change and that future shifts in forest structure can have large-scale community consequences.

Organizing urban ecosystem services through environmental stewardship governance in New York City

Science.gov (United States)

James J. Connolly; Erika S. Svendsen; Dana R. Fisher; Lindsay K. Campbell

2013-01-01

How do stewardship groups contribute to the management of urban ecosystem services? In this paper, we integrate the research on environmental stewardship with the social-ecological systems literature to explain how stewardship groups serve as bridge organizations between public agencies and civic organizations, working across scales and sectors to build the flexible...

Drought-induced xylem cavitation and hydraulic deterioration: risk factors for urban trees under climate change?

Science.gov (United States)

Savi, Tadeja; Bertuzzi, Stefano; Branca, Salvatore; Tretiach, Mauro; Nardini, Andrea

2015-02-01

Urban trees help towns to cope with climate warming by cooling both air and surfaces. The challenges imposed by the urban environment, with special reference to low water availability due to the presence of extensive pavements, result in high rates of mortality of street trees, that can be increased by climatic extremes. We investigated the water relations and xylem hydraulic safety/efficiency of Quercus ilex trees growing at urban sites with different percentages of surrounding impervious pavements. Seasonal changes of plant water potential and gas exchange, vulnerability to cavitation and embolism level, and morpho-anatomical traits were measured. We found patterns of increasing water stress and vulnerability to drought at increasing percentages of impervious pavement cover, with a consequent reduction in gas exchange rates, decreased safety margins toward embolism development, and increased vulnerability to cavitation, suggesting the occurrence of stress-induced hydraulic deterioration. The amount of impermeable surface and chronic exposure to water stress influence the site-specific risk of drought-induced dieback of urban trees under extreme drought. Besides providing directions for management of green spaces in towns, our data suggest that xylem hydraulics is key to a full understanding of the responses of urban trees to global change. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Tree rings provide early warning signals of jack pine mortality across a moisture gradient in the southern boreal forest

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Mamet, S. D.; Chun, K. P.; Metsaranta, J. M.; Barr, A. G.; Johnstone, J. F.

2015-08-01

Recent declines in productivity and tree survival have been widely observed in boreal forests. We used early warning signals (EWS) in tree ring data to anticipate premature mortality in jack pine (Pinus banksiana)—an extensive and dominant species occurring across the moisture-limited southern boreal forest in North America. We sampled tree rings from 113 living and 84 dead trees in three soil moisture regimes (subxeric, submesic, subhygric) in central Saskatchewan, Canada. We reconstructed annual increments of tree basal area to investigate (1) whether we could detect EWS related to mortality of individual trees, and (2) how water availability and tree growth history may explain the mortality warning signs. EWS were evident as punctuated changes in growth patterns prior to transition to an alternative state of reduced growth before dying. This transition was likely triggered by a combination of severe drought and insect outbreak. Higher moisture availability associated with a soil moisture gradient did not appear to reduce tree sensitivity to stress-induced mortality. Our results suggest tree rings offer considerable potential for detecting critical transitions in tree growth, which are linked to premature mortality.

Results of the radiological survey at 23 Lily Street, Albany, New York

International Nuclear Information System (INIS)

Espegren, M.L.; Marley, J.L.; Carrier, R.F.

1987-12-01

A number of properties in the Albany/Colonie area have been identified as being potentially contaminated with uranium originating from the former National Lead Company's uranium forming plant in Colonie, New York. The property at 23 Lily Street in Albany, New York (AL174), was the subject of a radiological investigation initiated July 21, 1986. The residential property consists of a two-story frame house located on a rectangular lot. An asphalt driveway connects the house to the street. A diagram of the property showing the approximate boundaries and the 5-m grid network established for measurements outside the house is shown. The lot included in the radiological survey was /approximately/20 m wide by 30 m deep. Front and side views of the property are shown. 13 refs., 5 figs., 5 tabs

Temperature response surfaces for mortality risk of tree species with future drought

Energy Technology Data Exchange (ETDEWEB)

Adams, Henry D.; Barron-Gafford, Greg A.; Minor, Rebecca L.; Gardea, Alfonso A.; Bentley, Lisa Patrick; Law, Darin J.; Breshears, David D.; McDowell, Nate G.; Huxman, Travis E.

2017-11-01

Widespread, high levels of tree mortality, termed forest die-off, associated with drought and rising temperatures, are disrupting forests worldwide. Drought will likely become more frequent with climate change, but even without more frequent drought, higher temperatures can exacerbate tree water stress. The temperature sensitivity of drought-induced mortality of tree species has been evaluated experimentally for only single-step changes in temperature (ambient compared to ambient + increase) rather than as a response surface (multiple levels of temperature increase), which constrains our ability to relate changes in the driver with the biological response. Here we show that time-to-mortality during drought for seedlings of two western United States tree species, Pinus edulis (Engelm.) and Pinus ponderosa (Douglas ex C. Lawson), declined in continuous proportion with increasing temperature spanning a 7.7 °C increase. Although P. edulis outlived P. ponderosa at all temperatures, both species had similar relative declines in time-to-mortality as temperature increased (5.2% per °C for P. edulis; 5.8% per °C for P. ponderosa). When combined with the non-linear frequency distribution of drought duration—many more short droughts than long droughts—these findings point to a progressive increase in mortality events with global change due to warming alone and independent of additional changes in future drought frequency distributions. As such, dire future forest recruitment patterns are projected assuming the calculated 7-9 seedling mortality events per species by 2100 under business-as-usual warming occurs, congruent with additional vulnerability predicted for adult trees from stressors like pathogens and pests. Our progressive projection for increased mortality events was driven primarily by the non-linear shape of the drought duration frequency distribution, a common climate feature of drought-affected regions. These

Temperature response surfaces for mortality risk of tree species with future drought

Science.gov (United States)

Adams, Henry D.; Barron-Gafford, Greg A.; Minor, Rebecca L.; Gardea, Alfonso A.; Bentley, Lisa Patrick; Law, Darin J.; Breshears, David D.; McDowell, Nate G.; Huxman, Travis E.

2017-11-01

Widespread, high levels of tree mortality, termed forest die-off, associated with drought and rising temperatures, are disrupting forests worldwide. Drought will likely become more frequent with climate change, but even without more frequent drought, higher temperatures can exacerbate tree water stress. The temperature sensitivity of drought-induced mortality of tree species has been evaluated experimentally for only single-step changes in temperature (ambient compared to ambient + increase) rather than as a response surface (multiple levels of temperature increase), which constrains our ability to relate changes in the driver with the biological response. Here we show that time-to-mortality during drought for seedlings of two western United States tree species, Pinus edulis (Engelm.) and Pinus ponderosa (Douglas ex C. Lawson), declined in continuous proportion with increasing temperature spanning a 7.7 °C increase. Although P. edulis outlived P. ponderosa at all temperatures, both species had similar relative declines in time-to-mortality as temperature increased (5.2% per °C for P. edulis; 5.8% per °C for P. ponderosa). When combined with the non-linear frequency distribution of drought duration—many more short droughts than long droughts—these findings point to a progressive increase in mortality events with global change due to warming alone and independent of additional changes in future drought frequency distributions. As such, dire future forest recruitment patterns are projected assuming the calculated 7-9 seedling mortality events per species by 2100 under business-as-usual warming occur, congruent with additional vulnerability predicted for adult trees from stressors like pathogens and pests. Our progressive projection for increased mortality events was driven primarily by the non-linear shape of the drought duration frequency distribution, a common climate feature of drought-affected regions. These results illustrate profound benefits for

Encoding phylogenetic trees in terms of weighted quartets.

Science.gov (United States)

Grünewald, Stefan; Huber, Katharina T; Moulton, Vincent; Semple, Charles

2008-04-01

One of the main problems in phylogenetics is to develop systematic methods for constructing evolutionary or phylogenetic trees. For a set of species X, an edge-weighted phylogenetic X-tree or phylogenetic tree is a (graph theoretical) tree with leaf set X and no degree 2 vertices, together with a map assigning a non-negative length to each edge of the tree. Within phylogenetics, several methods have been proposed for constructing such trees that work by trying to piece together quartet trees on X, i.e. phylogenetic trees each having four leaves in X. Hence, it is of interest to characterise when a collection of quartet trees corresponds to a (unique) phylogenetic tree. Recently, Dress and Erdös provided such a characterisation for binary phylogenetic trees, that is, phylogenetic trees all of whose internal vertices have degree 3. Here we provide a new characterisation for arbitrary phylogenetic trees.

Invasion of Winter Moth in New England: Effects of Defoliation and Site Quality on Tree Mortality

Directory of Open Access Journals (Sweden)

Michael J. Simmons

2014-10-01

Full Text Available Widespread and prolonged defoliation by the European winter moth, Operophtera brumata L., has occurred in forests of eastern Massachusetts for more than a decade and populations of winter moth continue to invade new areas of New England. This study characterized the forests of eastern Massachusetts invaded by winter moth and related the duration of winter moth defoliation estimated using dendrochronology to observed levels of tree mortality and understory woody plant density. Quercus basal area mortality in mixed Quercus and mixed Quercus—Pinus strobus forests in eastern Massachusetts ranged from 0–30%; mortality of Quercus in these forests was related to site quality and the number of winter moth defoliation events. In addition, winter moth defoliation events lead to a subsequent increase in understory woody plant density. Our results indicate that winter moth defoliation has been an important disturbance in New England forests that may have lasting impacts.

Which trees should be removed in thinning?

Directory of Open Access Journals (Sweden)

Timo Pukkala

2015-12-01

Full Text Available Background: In economically optimal management, trees that are removed in a thinning treatment should be selected on the basis of their value, relative value increment and the effect of removal on the growth of remaining trees. Large valuable trees with decreased value increment should be removed, especially when they overtop smaller trees. Methods: This study optimized the tree selection rule in the thinning treatments of continuous cover management when the aim is to maximize the profitability of forest management. The weights of three criteria (stem value, relative value increment and effect of removal on the competition of remaining trees were optimized together with thinning intervals. Results and conclusions: The results confirmed the hypothesis that optimal thinning involves removing predominantly large trees. Increasing stumpage value, decreasing relative value increment, and increasing competitive influence increased the likelihood that removal is optimal decision. However, if the spatial distribution of trees is irregular, it is optimal to leave large trees in sparse places and remove somewhat smaller trees from dense places. However, the benefit of optimal thinning, as compared to diameter limit cutting is not usually large in pure one-species stands. On the contrary, removing the smallest trees from the stand may lead to significant (30–40 % reductions in the net present value of harvest incomes. Keywords: Continuous cover forestry, Tree selection, High thinning, Optimal management, Spatial distribution, Spatial growth model

Urban air quality management : effects of trees on air pollution concentration in urban street canyon

NARCIS (Netherlands)

Salim, S.M.; Buccolieri, R.; Chan, A.; Sabatino, Di S.; Gromke, C.

2009-01-01

The aerodynamic effects of avenue-like tree planting on air flow and traffic-originated pollutant dispersion in urban built-up areas (i.e. street canyons of width to height ratio, W/H=1) are investigated using computational fluid dynamics techniques and complemented with extensive wind tunnel

Preliminary environmental site assessments in New York City

International Nuclear Information System (INIS)

Lundy, P.; Gasson, D.R.; Longendyke, S.T.

1991-01-01

Preliminary Environmental Site Assessments are often performed prior to real estate transactions or refinancing. These assessments are typically performed for real estate buyers, sellers and lending institutions. Undertaking a Preliminary Environmental Site Assessment in New York City can often be quite complex and time-consuming. This is due, in part, to the age and density of buildings in the city as well as the myriad of regulatory agencies with jurisdiction over environmental issues. This paper will discuss how environmental assessments are performed with a special emphasis on building in New York City. In includes hazardous wastes management for Radon, PCB's and asbestos

Trait Acclimation Mitigates Mortality Risks of Tropical Canopy Trees under Global Warming

NARCIS (Netherlands)

Sterck, Frank; Anten, Niels P.R.; Schieving, Feike; Zuidema, Pieter A.

2016-01-01

There is a heated debate about the effect of global change on tropical forests. Many scientists predict large-scale tree mortality while others point to mitigating roles of CO2 fertilization and – the notoriously unknown – physiological trait acclimation of trees. In this opinion article we provided

EnviroAtlas - New York, NY - Near Road Tree Buffer

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset addresses the tree buffer along heavily traveled roads. The roads are interstates, arterials, and collectors within the EnviroAtlas...

Changes in understory species occurrence of a secondary broadleaved forest after mass mortality of oak trees under deer foraging pressure

Directory of Open Access Journals (Sweden)

Hiroki Itô

2016-12-01

Full Text Available The epidemic of mass mortality of oak trees by Japanese oak wilt has affected secondary deciduous broadleaved forests that have been used as coppices in Japan. The dieback of oak trees formed gaps in the crown that would be expected to enhance the regeneration of shade-intolerant pioneer species. However, foraging by sika deer Cervus nippon has also affected forest vegetation, and the compound effects of both on forest regeneration should be considered when they simultaneously occur. A field study was conducted in Kyôto City, Japan to investigate how these compound effects affected the vegetation of the understory layer of these forests. The presence/absence of seedlings and saplings was observed for 200 quadrats sized 5 m ×5 m for each species in 1992, before the mass mortality and deer encroachment, and in 2014 after these effects. A hierarchical Bayesian model was constructed to explain the occurrence, survival, and colonization of each species with their responses to the gaps that were created, expanded, or affected by the mass mortality of Quercus serrata trees. The species that occurred most frequently in 1992, Eurya japonica, Quercus glauca, and Cleyera japonica, also had the highest survival probabilities. Deer-unpalatable species such as Symplocos prunifolia and Triadica sebifera had higher colonization rates in the gaps, while the deer-palatable species Aucuba japonica had the smallest survival probability. The gaps thus promoted the colonization of deer-unpalatable plant species such as Symplocos prunifolia and Triadica sebifera. In the future, such deer-unpalatable species may dominate gaps that were created, expanded, or affected by the mass mortality of oak trees.

The national tree-list layer

Science.gov (United States)

Stacy A. Drury; Jason M. Herynk

2011-01-01

The National Tree-List Layer (NTLL) project used LANDFIRE map products to produce the first national tree-list map layer that represents tree populations at stand and regional levels. The NTLL was produced in a short time frame to address the needs of Fire and Aviation Management for a map layer that could be used as input for simulating fire-caused tree mortality...

Assessing Vulnerability to Heat: A Geospatial Analysis for the City of Philadelphia

Directory of Open Access Journals (Sweden)

Laura Barron

2018-04-01

Full Text Available Urban heat island (UHI effect is an increasingly prominent health and environmental hazard that is linked to urbanization and climate change. Greening reduces the negative impacts of UHI; trees specifically are the most effective in ambient temperature reduction. This paper investigates vulnerability to heat in the Philadelphia, Pennsylvania and identifies where street trees can be planted as a public intervention. We used geospatial information systems (GIS software to map a validated Heat Vulnerability Index to identify vulnerability at the block level. Using a high-low geospatial cluster analysis, we assessed where the City of Philadelphia can most effectively plant street trees to address UHI. This information was then aggregated to the neighborhood level for more effective citizen communication and policymaking. We identified that 26 of 48 (54% neighborhoods that were vulnerable to heat also lacked street trees. Of 158 Philadelphia neighborhoods, 63 (40% contained block groups of high vulnerability to either heat or street tree infrastructure. Neighborhoods that were ranked highest in both classifications were identified in two adjacent West Philadelphia neighborhoods. Planting street trees is a public service a city can potentially reduce the negative health impacts of UHI. GIS can be used to identify and recommend street tree plantings to reduce urban heat.

“Gray Murder”: Characteristics of Elderly Compared With Nonelderly Homicide Victims in New York City

Science.gov (United States)

Abrams, Robert C.; Leon, Andrew C.; Tardiff, Kenneth; Marzuk, Peter M.; Sutherland, Kari

2007-01-01

Objectives. We compared characteristics of homicides among New York City residents aged 18 years and older from 1990 to 1998 to determine differences in demographics, cause and place of death, and presence of illicit drugs and alcohol in the deceased’s system. Methods. All medical examiner–certified homicides among New York City residents aged 18 years and older from 1990 to 1998 were studied (n = 11 850). Nonelderly (aged 18 to 64 years) and elderly (aged 65 years and older) victims were compared by gender, race/ethnicity, cause of death, place of death, and presence of illicit drugs or alcohol. Population-based homicide rates stratified by age, gender, and race were also calculated. Results. Nonelderly homicide victims were significantly more likely to be male, non-White, to have been shot in the city streets, and to have evidence of illicit drug or alcohol use. Elderly victims were more likely to be female, White, to have been killed by nonfirearm injuries, and to have been killed in their own homes. The gender and race differences between age groups remained but were attenuated when population-based rates were compared. Conclusions. The characteristics of homicide in nonelderly adults do not apply to elderly adults in New York City. Demographic factors and vulnerabilities of the elderly may underlie these differences, pointing to the need for oversight of isolated or homebound elderly persons and for protective interventions. PMID:17666708

Who are the Devils Wearing Prada in New York City?

OpenAIRE

Chen, KuanTing; Chen, Kezhen; Cong, Peizhong; Hsu, Winston H.; Luo, Jiebo

2015-01-01

Fashion is a perpetual topic in human social life, and the mass has the penchant to emulate what large city residents and celebrities wear. Undeniably, New York City is such a bellwether large city with all kinds of fashion leadership. Consequently, to study what the fashion trends are during this year, it is very helpful to learn the fashion trends of New York City. Discovering fashion trends in New York City could boost many applications such as clothing recommendation and advertising. Does...

New arrivals to New York City: vulnerability to HIV among urban migrant young gay men.

Science.gov (United States)

Kobrak, Paul; Ponce, Rafael; Zielony, Robert

2015-10-01

This qualitative study explored the social experiences and HIV-related sexual practices of 30 young gay and bisexual men who moved to New York City in the past 3 years from other countries or elsewhere in the United States. For many migrants, a key basis of vulnerability to HIV was their engagement with New York City's unfamiliar sexual culture. Many recent arrivals migrated from places with small gay communities and low HIV prevalence, and some came with a practice of limited condom use. Participants described encountering an abundance of sexual opportunity in New York City, accessible to even the newest arrivals through internet sex sites. Some migrants expressed surprise that few men they met were interested in dating or establishing trust before having sex. Although frequent HIV testing was common, HIV status, testing history, and condom use were seldom discussed with sex partners for some men even with new partners or before sex without condoms. International and in-country migrants who are beginning to navigate New York City's gay sexual culture may be more vulnerable to HIV infection than established residents if they are inexperienced in encountering vast sexual opportunity, are less practiced in local norms of sexual communication, or if their lack of economic resources or social connections encourages them to have sex for money or shelter. This article suggests HIV prevention interventions for urban migrants and other men who have sex with men.

EnviroAtlas - New York, NY - Estimated Percent Tree Cover Along Walkable Roads

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset estimates tree cover along walkable roads. The road width is estimated for each road and percent tree cover is calculated in a 8.5 meter...

Status and trend of tree growth and mortality rate at the CONECOFOR plots, 1997-2004

Directory of Open Access Journals (Sweden)

Gianfranco Fabbio

2013-11-01

Full Text Available The circumference of trees in the CONECOFOR permanent monitoring plots (PMPs were measured by three surveys carried out in 1997, 2000 and 2005. Plots were arranged into forest types according to tree species, management system and stand structure: beech (Fagus sylvatica L. and spruce (Picea abies K. high forests, aged coppice forests and transitory crops (deciduous, evergreen oaks and beech. Diameter distribution, basal area, basal area increment, tree mortality rate and in-growth were calculated per layer (dominant, intermediate, dominated within each PMP, to point out relative contributions and changes. A range in relative annual growth was detected both within and between types over the monitored period, but an obvious reduction of annual increment was found in two/thirds of plots over 2000-04 as compared to 1997-99. Current mortality, mostly allocated into the dominated and intermediate layers, can be explained as “regular” due to overstocking and high inter-tree competition in almost all of the observed case-studies. Opposite patterns were found to occur as for stand growth vs. mortality rate between coppice forests and the other types owing to the different dynamics of tree competition in progress. Drought 2003 is the likely large-scale factor determining the reduced annual growth course over the second period.

A joint individual-based model coupling growth and mortality reveals that tree vigor is a key component of tropical forest dynamics.

Science.gov (United States)

Aubry-Kientz, Mélaine; Rossi, Vivien; Boreux, Jean-Jacques; Hérault, Bruno

2015-06-01

Tree vigor is often used as a covariate when tree mortality is predicted from tree growth in tropical forest dynamic models, but it is rarely explicitly accounted for in a coherent modeling framework. We quantify tree vigor at the individual tree level, based on the difference between expected and observed growth. The available methods to join nonlinear tree growth and mortality processes are not commonly used by forest ecologists so that we develop an inference methodology based on an MCMC approach, allowing us to sample the parameters of the growth and mortality model according to their posterior distribution using the joint model likelihood. We apply our framework to a set of data on the 20-year dynamics of a forest in Paracou, French Guiana, taking advantage of functional trait-based growth and mortality models already developed independently. Our results showed that growth and mortality are intimately linked and that the vigor estimator is an essential predictor of mortality, highlighting that trees growing more than expected have a far lower probability of dying. Our joint model methodology is sufficiently generic to be used to join two longitudinal and punctual linked processes and thus may be applied to a wide range of growth and mortality models. In the context of global changes, such joint models are urgently needed in tropical forests to analyze, and then predict, the effects of the ongoing changes on the tree dynamics in hyperdiverse tropical forests.

Tree physiology and bark beetles

Science.gov (United States)

Michael G. Ryan; Gerard Sapes; Anna Sala; Sharon Hood

2015-01-01

Irruptive bark beetles usually co-occur with their co-evolved tree hosts at very low (endemic) population densities. However, recent droughts and higher temperatures have promoted widespread tree mortality with consequences for forest carbon, fire and ecosystem services (Kurz et al., 2008; Raffa et al., 2008; Jenkins et al., 2012). In this issue of New Phytologist,...

Estimating phylogenetic trees from genome-scale data.

Science.gov (United States)

Liu, Liang; Xi, Zhenxiang; Wu, Shaoyuan; Davis, Charles C; Edwards, Scott V

2015-12-01

The heterogeneity of signals in the genomes of diverse organisms poses challenges for traditional phylogenetic analysis. Phylogenetic methods known as "species tree" methods have been proposed to directly address one important source of gene tree heterogeneity, namely the incomplete lineage sorting that occurs when evolving lineages radiate rapidly, resulting in a diversity of gene trees from a single underlying species tree. Here we review theory and empirical examples that help clarify conflicts between species tree and concatenation methods, and misconceptions in the literature about the performance of species tree methods. Considering concatenation as a special case of the multispecies coalescent model helps explain differences in the behavior of the two methods on phylogenomic data sets. Recent work suggests that species tree methods are more robust than concatenation approaches to some of the classic challenges of phylogenetic analysis, including rapidly evolving sites in DNA sequences and long-branch attraction. We show that approaches, such as binning, designed to augment the signal in species tree analyses can distort the distribution of gene trees and are inconsistent. Computationally efficient species tree methods incorporating biological realism are a key to phylogenetic analysis of whole-genome data. © 2015 New York Academy of Sciences.

Biogeochemical processes on tree islands in the greater everglades: Initiating a new paradigm

Science.gov (United States)

Wetzel, P.R.; Sklar, Fred H.; Coronado, C.A.; Troxler, T.G.; Krupa, S.L.; Sullivan, P.L.; Ewe, S.; Price, R.M.; Newman, S.; Orem, W.H.

2011-01-01

Scientists' understanding of the role of tree islands in the Everglades has evolved from a plant community of minor biogeochemical importance to a plant community recognized as the driving force for localized phosphorus accumulation within the landscape. Results from this review suggest that tree transpiration, nutrient infiltration from the soil surface, and groundwater flow create a soil zone of confluence where nutrients and salts accumulate under the head of a tree island during dry periods. Results also suggest accumulated salts and nutrients are flushed downstream by regional water flows during wet periods. That trees modulate their environment to create biogeochemical hot spots and strong nutrient gradients is a significant ecological paradigm shift in the understanding of the biogeochemical processes in the Everglades. In terms of island sustainability, this new paradigm suggests the need for distinct dry-wet cycles as well as a hydrologic regime that supports tree survival. Restoration of historic tree islands needs further investigation but the creation of functional tree islands is promising. Copyright ?? 2011 Taylor & Francis Group, LLC.

Mortality and recruitment of trees in a tropical rain forest of Choco (Colombia)

International Nuclear Information System (INIS)

Quinto M, Harley; Rengifo I, Reimer; Ramos P, Yan

2009-01-01

A Rates of mortality and recruitment of trees were calculated in a permanent research plot established in the tropical wet forest. The study was based on two measurements, one was done in 1998 and the other in 2005, in which were measured the diameter (DBH) of trees with DBH>10 cm and surveyed dead and recruited trees. We also determined the type of mortality, the mortality and exponential recruitment coefficient, the aboveground biomass (AB) and the mean life of the forest. In the first census 709 individuals were recorded and 710 in the second one. The mean annual mortality rate of trees was 1.39% and the exponential mortality coefficient was 1.41%; the most common types of mortality were uprooting and snags. Annual recruitment rate was 1.2% and the exponential rate of recruitment was 1.19%. Mean life of this forest was estimated in 58.6 years. The AB was of 237.31 t ha-1 in the year 1998, and in the 2005 was of 259.9 t ha-1. The recruited individuals presented AB of 5.08 t ha-1, and the dead of 17.72 t ha-1; the increment of AB in survivors was 30.97 t ha-1 average. Similarity of number of individuals between measurements, as well as in the other parameters evaluated, suggest a possible balance between mortality and recruitment of this forest. Based on the results of this study, we could no reject the hypothesis of dynamic equilibrium of this tropical wet forest.

Monitoring Million Trees LA: Tree performance during the early years and future benefits

Science.gov (United States)

E. Gregory McPherson

2014-01-01

Million Trees LA (MTLA) is one of several large-scale mayoral tree planting initiatives striving to create more livable cities through urban forestry. This study combined field sampling of tree survival and growth with numerical modeling of future benefits to assess performance of MTLA plantings. From 2006 to 2010 MTLA planted a diverse mix of 91,786 trees....

Can forest dieback and tree death be predicted by prior changes in wood anatomy?

Science.gov (United States)

Colangelo, Michele; Julio Camarero, Jesus; De Micco, Veronica; Borghetti, Marco; Gentilesca, Tiziana; Sanchez-Salguero, Raul; Ripullone, Francesco

2017-04-01

Climate warming is expected to amplify drought stress resulting in more intense and widespread dieback episodes and increasing mortality rates. Studies on quantitative wood anatomy and dendrochronology have demonstrated their potential to supply useful information on the causes of tree decline, although this approach is basically observational and retrospective. Moreover, the long-term reconstruction of wood anatomical features, strictly linked to the evolution of xylem anatomy plasticity through time, allow investigating hydraulic adjustments of trees. In this study, we analyzed wood-anatomical variables in two Italian oak forests where recent episodes of dieback and mortality have been reported. We analyzed in coexisting now-dead and living trees the following wood-anatomical variables: annual tree-ring area, earlywood (EW) and latewood (LW) areas, absolute and relative (%) areas occupied by vessels in the EW and LW, EW and LW vessel areas, EW and LW vessel density and vessel diameter classification. We also calculated the hydraulic diameter (Dh) for all vessels measured within each ring by weighting individual conduit diameters to correspond to the average Hagen-Poiseuille lumen theoretical hydraulic conductivity for a vessel size. Wood-anatomical analyses showed that declining and dead trees were more sensitive to drought stress compared to non declining trees, indicating different susceptibility to water shortage between trees. Dead trees did not form earlywood vessels with smaller lumen diameter than surviving trees but tended to form wider latewood vessels with a higher percentage of vessel area. We discuss the results and implications focusing on those proved more sensitive to the phenomena of decline and mortality.

Improving local air quality in cities: To tree or not to tree?

International Nuclear Information System (INIS)

Vos, Peter E.J.; Maiheu, Bino; Vankerkom, Jean; Janssen, Stijn

2013-01-01

Vegetation is often quoted as an effective measure to mitigate urban air quality problems. In this work we demonstrate by the use of computer models that the air quality effect of urban vegetation is more complex than implied by such general assumptions. By modelling a variety of real-life examples we show that roadside urban vegetation rather leads to increased pollutant concentrations than it improves the air quality, at least locally. This can be explained by the fact that trees and other types of vegetation reduce the ventilation that is responsible for diluting the traffic emitted pollutants. This aerodynamic effect is shown to be much stronger than the pollutant removal capacity of vegetation. Although the modelling results may be subject to a certain level of uncertainty, our results strongly indicate that the use of urban vegetation for alleviating a local air pollution hotspot is not expected to be a viable solution. Highlights: ► We model the impact of roadside urban vegetation on the local air quality. ► Vegetation in general lowers the wind speed thereby reducing the ventilation. ► In general roadside urban vegetation does not appear to decrease concentrations. ► Roadside urban trees have a pronounced detrimental effect on the local air quality. ► City planners and policy makers need to be better informed about this topic. -- Rather than improving the local air quality, our results suggest that roadside urban vegetation increases the pollutant concentrations at the footpath

Analysis of tree bark samples for air pollution biomonitoring of an urban area

International Nuclear Information System (INIS)

Martins, Ana Paula G.; Negri, Elnara M.; Saldiva, Paulo H.N.

2009-01-01

Air pollution is receiving much attention as a public health problem around the world due to its adverse health effects from exposures by urban populations. Within this context, the use of vegetal biomonitoring to evaluate air quality has been investigated throughout the world. Air pollutant levels are high in the city of Sao Paulo, SP, Brazil and being the vehicle emissions its main source. The aim of this study was to evaluate concentrations of As, Ba, Br, Ca, Co, Cr, Cu, Fe, Mn, Pb, S, Sb and Zn in tree bark samples used as biomonitor of urban air pollution. Concentrations of these elements were determined in barks collected in trees of the Ibirapuera Park, one of the biggest and most visited parks of the city of Sao Paulo city. Samples of tree barks were also collected in a site outside the city of Sao Paulo, in a rural area of Embu-Guacu, considered as a control site. The element concentrations were determined by the methods of Instrumental Neutron Activation Analysis (INAA) and of Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF). The findings of this study showed that tree bark samples may be used as biomonitors of urban air pollution in a micro scale, and both techniques, INAA and EDXRF, can be used to evaluate element concentrations in tree bark samples. (author)

High-latitude tree-ring data: Records of climatic change and ecological response

International Nuclear Information System (INIS)

Graumlich, L.J.

1991-01-01

Tree-ring data provide critical information regarding two fundamental questions as to the role of the polar regions in global change: (1) what is the nature of climatic variability? and (2) what is the response of vegetation to climatic variability? Tree-ring-based climatic reconstructions document the variability of the climate system on time scales of years to centuries. Dendroclimatic reconstructions indicate that the climatic episodes defined on the basis of documentary evidence in western Europe (i.e., Medieval Warm Episode, ca. A.D. 1000-1300; Little Ice Age, ca. A.D. 1550-1850) can be observed at some high-latitude sites (ex., Polar Urals). Spatial variation in long-term temperature trends (ex., northern Fennoscandia vs. Polar Urals) demonstrates the importance of regional-scale climatic controls. When collated into global networks, proxy-based climatic reconstructions can be used to test hypotheses as to the relative importance of external forcing vs. internal variation in governing climatic variation. Specifically, such a global network would allow the quantification of the climatic response to various permutations of factors thought to be important in governing decadal- to centennial-scale climatic variation. Tree populations respond to annual- to centennial-scale climatic variation through changes in rates of growth, establishment, and mortality. Tree-ring studies that document multiple aspects of high-latitude treeline dynamics (i.e., the timing of tree establishment, mortality, and changes from krummholz to upright growth) indicate a complex interaction between growth form, population processes, and environmental variability. Such interactions result in varying sensitivities of high-latitude trees to climatic change

Research Article Cancer Mortality among Asians and Pacific Islanders in New York City, 2001–2010

International Nuclear Information System (INIS)

Huang, V.; Li, W.; Tsai, J.; Begier, E.

2013-01-01

Asians and Pacific Islanders’ (APIs) leading cause of death is cancer. We compared APIs’ age-adjusted cancer mortality rates to other racial/ethnic groups and by API subgroup (i.e., Chinese, Koreans, Asian Indians, and Filipinos) using New York City (NYC) Mortality data and Census Bureau population estimates for 2001-2010. While other racial/ethnic groups’ overall cancer mortality rates declined in NYC during the last decade, APIs remained stable. APIs overall had the lowest mortality rates for more common cancer types (i.e., lung, colorectal, breast, and prostate), but the highest mortality rates for certain less common cancers (i.e., nasopharyngeal, stomach, and liver). Chinese New Yorkers’ lung cancer death rates were very high compared to other APIs and comparable to non-Hispanic whites (47.1/100,000 versus 49.5/100,000, resp.). Chinese men had much higher nasopharyngeal cancer mortality rates (4.5/100,000 versus 0.3/100,000 for non-Hispanic whites). Korean men had the highest liver and stomach cancer mortality rates (25.3/100,000 and 27.7/100,000, resp., versus 7.9/100,000 and 6.0/100,000 for non-Hispanic whites). Analysis of cancer rates by API subgroup provides the detailed information needed to plan cancer prevention efforts. These findings warrant consideration of targeted cancer mortality prevention efforts for affected subgroups, including hepatitis vaccination, screening, and treatment; smoking cessation; and cancer screening.

Modeled PM2.5 removal by trees in ten US cities and associated health effects

Science.gov (United States)

David J. Nowak; Satoshi Hirabayashi; Allison Bodine; Robert. Hoehn

2013-01-01

Urban particulate air pollution is a serious health issue. Trees within cities can remove fine particles from the atmosphere and consequently improve air quality and human health. Tree effects on PM2.5 concentrations and human health are modeled for 10 U.S. cities. The total amount of PM2.5 removed annually by...

Eucalyptus as a landscape tree

Science.gov (United States)

W. Douglas Hamilton

1983-01-01

Ninety-two species of Eucalyptus were evaluated at the University of California re- search station in San Jose. The purpose: to find acceptable new street and park trees. Growth rates and horticultural characteristics were noted. Forty-three species were studied in locations statewide to evaluate site adaptation and landscape usefulness; flooded, cold, dry, saline....

Tree compression with top trees

DEFF Research Database (Denmark)

Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

2013-01-01

We introduce a new compression scheme for labeled trees based on top trees [3]. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

Tree compression with top trees

DEFF Research Database (Denmark)

Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

2015-01-01

We introduce a new compression scheme for labeled trees based on top trees. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

Can community members identify tropical tree species for REDD+ carbon and biodiversity measurements?

DEFF Research Database (Denmark)

Zhao, Mingxu; Brofeldt, Søren; Li, Qiaohong

2016-01-01

to take advantage of the same data for detecting changes in the tree diversity, using the richness and abundance of canopy trees as a proxy for biodiversity. If local community members are already assessing the above-ground biomass in a representative network of forest vegetation plots, it may require...... minimal further effort to collect data on the diversity of trees. We compare community members and trained scientists' data on tree diversity in permanent vegetation plots in montane forest in Yunnan, China. We show that local community members here can collect tree diversity data of comparable quality...... to trained botanists, at one third the cost. Without access to herbaria, identification guides or the Internet, community members could provide the ethno-taxonomical names for 95% of 1071 trees in 60 vegetation plots. Moreover, we show that the community-led survey spent 89% of the expenses at village level...

Lead (Pb) and other metals in New York City community garden soils: Factors influencing contaminant distributions

International Nuclear Information System (INIS)

Mitchell, Rebecca G.; Spliethoff, Henry M.; Ribaudo, Lisa N.; Lopp, Donna M.; Shayler, Hannah A.; Marquez-Bravo, Lydia G.; Lambert, Veronique T.; Ferenz, Gretchen S.; Russell-Anelli, Jonathan M.; Stone, Edie B.; McBride, Murray B.

2014-01-01

Urban gardens provide affordable fresh produce to communities with limited access to healthy food but may also increase exposure to lead (Pb) and other soil contaminants. Metals analysis of 564 soil samples from 54 New York City (NYC) community gardens found at least one sample exceeding health-based guidance values in 70% of gardens. However, most samples (78%) did not exceed guidance values, and medians were generally below those reported in NYC soil and other urban gardening studies. Barium (Ba) and Pb most frequently exceeded guidance values and along with cadmium (Cd) were strongly correlated with zinc (Zn), a commonly measured nutrient. Principal component analysis suggested that contaminants varied independently from organic matter and geogenic metals. Contaminants were associated with visible debris and a lack of raised beds; management practices (e.g., importing uncontaminated soil) have likely reduced metals concentrations. Continued exposure reduction efforts would benefit communities already burdened by environmental exposures. - Highlights: • We measured metals concentrations in soil from 54 New York City community gardens. • Pb and Ba exceeded health-based guidance values in 9%–12% of garden beds. • Pb concentrations were similar to those in other studies of urban garden soils. • Pb and Ba were associated with Zn, with visible debris, and with non-raised beds. • Observable details can help gardeners focus testing and exposure reduction efforts. - Pb and Ba, which exceeded health-based guidance values in 10–14% of NYC community garden soil samples, are associated with non-raised beds, visible debris, higher pH and Zn

Storm surge modeling of Superstorm Sandy in the New York City Metropolitan area

Science.gov (United States)

Benimoff, A. I.; Blanton, B. O.; Dzedzits, E.; Fritz, W. J.; Kress, M.; Muzio, P.; Sela, L.

2013-12-01

Even though the New York/New Jersey area does not lie within the typical 'hurricane belt', recent events and the historical record indicate that large infrequent tropical storms have had direct hits on the region, with impacts being amplified due to the nearly right angle bend in the coastline. The recent plan unveiled by New York City's Mayor Bloomberg lays out mitigation strategies to protect the region's communities, infrastructure, and assets from future storms, and numerical simulation of storm surge and wave hazards driven by potential hurricanes plays a central role in developing and evaluating these strategies. To assist in local planning, recovery, and decision-making, we have used the tide, storm surge, and wind wave model ADCIRC+SWAN to simulate storm surge in one of the most populated areas of the United States: the New York City (NYC) metropolitan area. We have generated a new high-resolution triangular finite-element model grid for the region from recent USGS data as well as recent city topographic maps at 2-foot (0.6m) contour intervals, nautical charts, and details of shipping channels. Our hindcast simulations are compared against Superstorm Sandy. We used the City University of New York High Performance Computing Center's Cray XE6tm at the College of Staten Island for these simulations. Hindcasting and analysis of the Superstorm Sandy storm surge and waves indicates that our simulations produce a reasonable representation of actual events. The grid will be used in an ADCIRC-based forecasting system implementation for the region.

Estimating Coextinction Risks from Epidemic Tree Death: Affiliate Lichen Communities among Diseased Host Tree Populations of Fraxinus excelsior

Science.gov (United States)

Jönsson, Mari T.; Thor, Göran

2012-01-01

At least 10% of the world’s tree species are threatened with extinction and pathogens are increasingly implicated in tree threats. Coextinction and threats to affiliates as a consequence of the loss or decline of their host trees is a poorly understood phenomenon. Ash dieback is an emerging infectious disease causing severe dieback of common ash Fraxinus excelsior throughout Europe. We utilized available empirical data on affiliate epiphytic lichen diversity (174 species and 17,800 observations) among 20 ash dieback infected host tree populations of F. excelsior on the island Gotland in the Baltic Sea, Sweden. From this, we used structured scenario projections scaled with empirical data of ash dieback disease to generate probabilistic models for estimating local and regional lichen coextinction risks. Average coextinction probabilities (Ā) were 0.38 (95% CI ±0.09) for lichens occurring on F. excelsior and 0.14 (95% CI ±0.03) when considering lichen persistence on all tree species. Ā was strongly linked to local disease incidence levels and generally increasing with lichen host specificity to F. excelsior and decreasing population size. Coextinctions reduced affiliate community viability, with significant local reductions in species richness and shifts in lichen species composition. Affiliates were projected to become locally extirpated before their hosts, illuminating the need to also consider host tree declines. Traditionally managed open wooded meadows had the highest incidence of ash dieback disease and significantly higher proportions of affiliate species projected to go extinct, compared with unmanaged closed forests and semi-open grazed sites. Most cothreatened species were not previously red-listed, which suggest that tree epidemics cause many unforeseen threats to species. Our analysis shows that epidemic tree deaths represent an insidious, mostly overlooked, threat to sessile affiliate communities in forested environments. Current conservation and

Tree mortality estimates and species distribution probabilities in southeastern United States forests

Science.gov (United States)

Martin A. Spetich; Zhaofei Fan; Zhen Sui; Michael Crosby; Hong S. He; Stephen R. Shifley; Theodor D. Leininger; W. Keith Moser

2017-01-01

Stresses to trees under a changing climate can lead to changes in forest tree survival, mortality and distribution.  For instance, a study examining the effects of human-induced climate change on forest biodiversity by Hansen and others (2001) predicted a 32% reduction in loblolly–shortleaf pine habitat across the eastern United States.  However, they also...

Impact of local traffic exclusion on near-road air quality: findings from the New York City "Summer Streets" campaign.

Science.gov (United States)

Whitlow, Thomas H; Hall, Andrew; Zhang, K Max; Anguita, Juan

2011-01-01

We monitored curbside airborne particulate matter (PM) concentrations and its proinflammatory capacity during 3 weekends when vehicle traffic was excluded from Park. Ave., New York City. Fine PM concentration peaked in the morning regardless of traffic while ultrafine PM was 58% lower during mornings without traffic. Ultrafine PM concentration varied linearly with traffic flow, while fine PM spiked sharply in response to random traffic events that were weakly correlated with the traffic signal cycle. Ultrafine PM concentrations decayed exponentially with distance from a cross street with unrestricted traffic flow, reaching background levels within 100 m of the source. IL-6 induction was typically highest on Friday afternoons but showed no clear relationship to the presence of traffic. The coarse fraction (>2.5 μm) had the greatest intrinsic inflammatory capacity, suggesting that coarse PM still warrants attention even as the research focus is shifting to nano-particles. Copyright © 2011 Elsevier Ltd. All rights reserved.

Spatially nonrandom tree mortality and ingrowth maintain equilibrium pattern in an old-growth Pseudotsuga-Tsuga forest.

Science.gov (United States)

Lutz, James A; Larson, Andrew J; Furniss, Tucker J; Donato, Daniel C; Freund, James A; Swanson, Mark E; Bible, Kenneth J; Chen, Jiquan; Franklin, Jerry F

2014-08-01

Mortality processes in old-growth forests are generally assumed to be driven by gap-scale disturbance, with only a limited role ascribed to density-dependent mortality, but these assumptions are rarely tested with data sets incorporating repeated measurements. Using a 12-ha spatially explicit plot censused 13 years apart in an approximately 500-year-old Pseudotsuga-Tsuga forest, we demonstrate significant density-dependent mortality and spatially aggregated tree recruitment. However, the combined effect of these strongly nonrandom demographic processes was to maintain tree patterns in a state of dynamic equilibrium. Density-dependent mortality was most pronounced for the dominant late-successional species, Tsuga heterophylla. The long-lived, early-seral Pseudotsuga menziesii experienced an annual stem mortality rate of 0.84% and no new recruitment. Late-seral species Tsuga and Abies amabilis had nearly balanced demographic rates of ingrowth and mortality. The 2.34% mortality rate for Taxus brevifolia was higher than expected, notably less than ingrowth, and strongly affected by proximity to Tsuga. Large-diameter Tsuga structured both the regenerating conspecific and heterospecific cohorts with recruitment of Tsuga and Abies unlikely in neighborhoods crowded with large-diameter competitors (P old-growth forests.

Looking for age-related growth decline in natural forests: unexpected biomass patterns from tree rings and simulated mortality

Science.gov (United States)

Foster, Jane R.; D'Amato, Anthony W.; Bradford, John B.

2014-01-01

Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with a census tree-ring data set from eight temperate forest types to reconstruct stand-level biomass increments (in Minnesota, USA). We compared growth patterns among mortality models, forest types and stands. Timing of peak biomass growth varied significantly among mortality models, peaking 20–30 years earlier when mortality was random with respect to tree growth and size, than when mortality favored slow-growing individuals. Random or u-shaped mortality (highest in small or large trees) produced peak growth 25–30 % higher than the surviving tree sample alone. Growth trends for even-aged, monospecific Pinus banksiana or Acer saccharum forests were similar to the early peak and decline expectation. However, we observed continually increasing biomass growth in older, low-productivity forests of Quercus rubra, Fraxinus nigra, and Thuja occidentalis. Tree-ring reconstructions estimated annual changes in live biomass growth and identified more diverse development patterns than previous methods. These detailed, long-term patterns of biomass development are crucial for detecting recent growth responses to global change and modeling future forest dynamics.

New York - New Jersey Highlands Regional Study: 2002 Update

Science.gov (United States)

Northeastern Area State and Private Forestry

2003-01-01

Stewardship Goals For The New York - New Jersey Highlands This 2002 Update of the 1992 New York - New Jersey Highlands Regional Study embodies the following goals for the long-term stewardship of the Highlands: 1. Manage future growth that is compatible with the region's ecological constraints; 2. Maintain an adequate surface and ground water supply that...

Improving Predictions of Tree Drought Mortality in the Community Land Model Using Hydraulic Physiology Theory and its Effects on Carbon Metabolism

Science.gov (United States)

McNellis, B.; Hudiburg, T. W.

2017-12-01

Tree mortality due to drought is predicted to have increasing impacts on ecosystem structure and function during the 21st century. Models can attempt to predict which forests are most at risk from drought, but novel environments may preclude analysis that relies on past observations. The inclusion of more mechanistic detail may reduce uncertainty in predictions, but can also compound model complexity, especially in global models. The Community Land Model version 5 (CLM5), itself a component of the Community Earth System Model (CESM), has recently integrated cohort-based demography into its dynamic vegetation component and is in the process of coupling this demography to a model of plant hydraulic physiology (FATES-Hydro). Previous treatment of drought stress and plant mortality within CLM has been relatively broad, but a detailed hydraulics module represents a key step towards accurate mortality prognosis. Here, we examine the structure of FATES-Hydro with respect to two key physiological attributes: tissue osmotic potentials and embolism refilling. Specifically, we ask how FATES-Hydro captures mechanistic realism within each attribute and how much support there is within the physiological literature for its further elaboration within the model structure. Additionally, connections to broader aspects of carbon metabolism within FATES are explored to better resolve emergent consequences of drought stress on ecosystem function and tree demographics. An on-going field experiment in managed stands of Pinus ponderosa and mixed conifers is assessed for model parameterization and performance across PNW forests, with important implications for future forest management strategy.

Influence of repeated prescribed fire on tree growth and mortality in Pinus resinosa forests, northern Minnesota

Science.gov (United States)

Bottero, Alessandra; D'Amato, Anthony W.; Palik, Brian J.; Kern, Christel C.; Bradford, John B.; Scherer, Sawyer S.

2017-01-01

Prescribed fire is widely used for ecological restoration and fuel reduction in fire-dependent ecosystems, most of which are also prone to drought. Despite the importance of drought in fire-adapted forests, little is known about cumulative effects of repeated prescribed burning on tree growth and related response to drought. Using dendrochronological data in red pine (Pinus resinosa Ait.)-dominated forests in northern Minnesota, USA, we examined growth responses before and after understory prescribed fires between 1960 and 1970, to assess whether repeated burning influences growth responses of overstory trees and vulnerability of overstory tree growth to drought. We found no difference in tree-level growth vulnerability to drought, expressed as growth resistance, resilience, and recovery, between areas receiving prescribed fire treatments and untreated forests. Annual mortality rates during the period of active burning were also low (less than 2%) in all treatments. These findings indicate that prescribed fire can be effectively integrated into management plans and climate change adaptation strategies for red pine forest ecosystems without significant short- or long-term negative consequences for growth or mortality rates of overstory trees.

FEASIBILITY STUDY FOR POTASSIUM IODIDE (KI) DISTRIBUTION IN NEW YORK CITY

International Nuclear Information System (INIS)

MOSS, STEVEN

2005-01-01

The New York City Department of Health and Mental Hygiene (DOHMH), Bureau of Environmental Science and Engineering, Office of Radiological Health (ORH) [as the primary local technical consultant in the event of a radiological or nuclear incident within the boundaries of New York City] requested the assistance of Brookhaven National Laboratory (BNL) with the development of a Feasibility Study for Potassium Iodide (KI) distribution in the unlikely event of a significant release of radioactive iodine in or near New York City. Brookhaven National Laboratory had previously provided support for New York City with the development of the radiological/nuclear portions of its All Hazards Emergency Response Plans. The work is funded by Medical and Health Research Association (MHRA) of New York City, Inc., under a work grant by the Federal Centers for Disease Control (CDC) for Public Health Preparedness and Response for Bioterrorism. This report is part of the result of that effort. The conclusions of this report are that: (1) There is no credible radiological scenario that would prompt the need for large segments of the general population of New York City to take KI as a result of a projected plume exposure to radioiodine reaching even the lowest threshold of 5 rem to the thyroid; and (2) KI should be stockpiled in amounts and locations sufficient for use by first responders/emergency responders in response to any localized release of radioiodine

FEASIBILITY STUDY FOR POTASSIUM IODIDE (KI) DISTRIBUTION IN NEW YORK CITY.

Energy Technology Data Exchange (ETDEWEB)

MOSS, STEVEN

2005-04-29

The New York City Department of Health and Mental Hygiene (DOHMH), Bureau of Environmental Science and Engineering, Office of Radiological Health (ORH) [as the primary local technical consultant in the event of a radiological or nuclear incident within the boundaries of New York City] requested the assistance of Brookhaven National Laboratory (BNL) with the development of a Feasibility Study for Potassium Iodide (KI) distribution in the unlikely event of a significant release of radioactive iodine in or near New York City. Brookhaven National Laboratory had previously provided support for New York City with the development of the radiological/nuclear portions of its All Hazards Emergency Response Plans. The work is funded by Medical and Health Research Association (MHRA) of New York City, Inc., under a work grant by the Federal Centers for Disease Control (CDC) for Public Health Preparedness and Response for Bioterrorism. This report is part of the result of that effort. The conclusions of this report are that: (1) There is no credible radiological scenario that would prompt the need for large segments of the general population of New York City to take KI as a result of a projected plume exposure to radioiodine reaching even the lowest threshold of 5 rem to the thyroid; and (2) KI should be stockpiled in amounts and locations sufficient for use by first responders/emergency responders in response to any localized release of radioiodine.

Trait acclimation mitigates mortality risks of tropical canopy trees under global warming

Directory of Open Access Journals (Sweden)

Frank eSterck

2016-05-01

Full Text Available There is a heated debate about the effect of global change on tropical forests. Many scientists predict large-scale tree mortality while others point to mitigating roles of CO2 fertilization and – the notoriously unknown – physiological trait acclimation of trees. In this opinion article we provided a first quantification of the potential of trait acclimation to mitigate the negative effects of warming on tropical canopy tree growth and survival. We applied a physiological tree growth model that incorporates trait acclimation through an optimization approach. Our model estimated the maximum effect of acclimation when trees optimize traits that are strongly plastic on a week to annual time scale (leaf photosynthetic capacity, total leaf area, stem sapwood area to maximize carbon gain. We simulated tree carbon gain for temperatures (25-35ºC and ambient CO2 concentrations (390-800 ppm predicted for the 21st century. Full trait acclimation increased simulated carbon gain by up to 10-20% and the maximum tolerated temperature by up to 2ºC, thus reducing risks of tree death under predicted warming. Functional trait acclimation may thus increase the resilience of tropical trees to warming, but cannot prevent tree death during extremely hot and dry years at current CO2 levels. We call for incorporating trait acclimation in field and experimental studies of plant functional traits, and in models that predict responses of tropical forests to climate change.

Trait Acclimation Mitigates Mortality Risks of Tropical Canopy Trees under Global Warming

Science.gov (United States)

Sterck, Frank; Anten, Niels P. R.; Schieving, Feike; Zuidema, Pieter A.

2016-01-01

There is a heated debate about the effect of global change on tropical forests. Many scientists predict large-scale tree mortality while others point to mitigating roles of CO2 fertilization and – the notoriously unknown – physiological trait acclimation of trees. In this opinion article we provided a first quantification of the potential of trait acclimation to mitigate the negative effects of warming on tropical canopy tree growth and survival. We applied a physiological tree growth model that incorporates trait acclimation through an optimization approach. Our model estimated the maximum effect of acclimation when trees optimize traits that are strongly plastic on a week to annual time scale (leaf photosynthetic capacity, total leaf area, stem sapwood area) to maximize carbon gain. We simulated tree carbon gain for temperatures (25–35°C) and ambient CO2 concentrations (390–800 ppm) predicted for the 21st century. Full trait acclimation increased simulated carbon gain by up to 10–20% and the maximum tolerated temperature by up to 2°C, thus reducing risks of tree death under predicted warming. Functional trait acclimation may thus increase the resilience of tropical trees to warming, but cannot prevent tree death during extremely hot and dry years at current CO2 levels. We call for incorporating trait acclimation in field and experimental studies of plant functional traits, and in models that predict responses of tropical forests to climate change. PMID:27242814

Tree Canopy Characterization for EO-1 Reflective and Thermal Infrared Validation Studies: Rochester, New York

Science.gov (United States)

Ballard, Jerrell R., Jr.; Smith, James A.

2002-01-01

The tree canopy characterization presented herein provided ground and tree canopy data for different types of tree canopies in support of EO-1 reflective and thermal infrared validation studies. These characterization efforts during August and September of 2001 included stem and trunk location surveys, tree structure geometry measurements, meteorology, and leaf area index (LAI) measurements. Measurements were also collected on thermal and reflective spectral properties of leaves, tree bark, leaf litter, soil, and grass. The data presented in this report were used to generate synthetic reflective and thermal infrared scenes and images that were used for the EO-1 Validation Program. The data also were used to evaluate whether the EO-1 ALI reflective channels can be combined with the Landsat-7 ETM+ thermal infrared channel to estimate canopy temperature, and also test the effects of separating the thermal and reflective measurements in time resulting from satellite formation flying.

New York City’s First Responders: Enhancing Collaboration Between NYPD and FDNY

Science.gov (United States)

2014-12-01

details about chronic conditions that plague communities (e.g., guns, drugs, human trafficking ). Put simply, the lack of information sharing is...both departments combined with a human element (i.e., egos) can contribute to their autonomous mindset. Although the mission for both agencies is...and more utilitarian functions for the police and fire service that may be lacking in New York City. By such a comparison, the city of White Plains

"Chronicity," "nervios" and community care: a case study of Puerto Rican psychiatric patients in New York City.

Science.gov (United States)

Swerdlow, M

1992-06-01

The role of ethnicity, community structure, and folk concepts of mental illness in facilitating the adaptation of long term psychiatric patients to community living has received little attention. This article examines the cultural concepts of mental illness and the community involvement of 30 Puerto Rican psychiatric patients participating in a New York City treatment program. It is shown that many of the attributes usually associated with chronic mental illness do not apply to this population. It is argued that the folk concept of nervios helps to foster the integration of these patients in a wide range of community networks. The impact of gentrification on these patients' community integration is also discussed.

Radiocarbon (14C) Concentration of Local Pollution in Street Trees Located at Intersections

OpenAIRE

Ogawa, Daisuke

2018-01-01

At large intersections, vehicles consume and generate a large amount of fossil fuel. Carbon derived from fossil fuels that do not contain radioactive carbon (14C), i.e., dead carbon, is released in large amounts in the roadside air environment. By means of photosynthesis, street trees along the roadside assimilate both dead carbon, not containing radioactive carbon (14C), and contemporary carbon, which includes radioactive carbon (14C). Therefore, the concentration of radioactive carbon (14C)...

Multiple-purpose trees for pastoral farming in New Zealand: with emphasis on tree legumes. [Lucerne Tree: Medick Tree

Energy Technology Data Exchange (ETDEWEB)

Davies, D J.G.; Macfarlane, R P

1979-01-01

The potential for soil conservation and agroforestry of several native and exotic legumes is discussed. Flowering period, chemical composition of leaves/pods, hardiness to frost and drought, timber value, forage potential for livestock and bees, ornamental value and other products are tabulated with information on up to 38 species. Two low-growing species that have proved useful for slope stabilization as well as forage are tree lucerne (Cytisus palmensis) and tree medick (Medicago arborea), the latter being shrubby and more suitable for cold districts. Gleditsia triacanthos is recommended as a shade and fodder tree for farm pasture.

The effect of contaminated groundwater on tree growth: A tree-ring analysis

International Nuclear Information System (INIS)

LeBlanc, D.C.; Loehle, C.

1990-10-01

A study was conducted on the effect of contaminated groundwater seepage on tree growth downslope from F- and H-Area seepage basins of the Savannah River Site. Trees in wetlands along Four Mile Creek began to show localized stress and mortality in the late 1970s. Extreme winter temperatures and high rainfall were ruled out as potential causal factors of tree stress. Drought was shown to affect trees in both contaminated and uncontaminated zones, but trees in uncontaminated areas exhibit better recovery after drought than trees in contaminated areas. Pollution-mediated alteration of soil acidity and aluminum, sodium, and heavy metal concentrations likely acted to predispose trees to decline, with severe drought acting as the trigger for decline initiation and tree death. Thus, a moderate pollution loading, not sufficient to cause visible damage of itself, may create conditions in which sudden, severe decline could result from natural stresses. This mechanism of forest decline is common, and should be considered in evaluations of the impact of pollution on wetland forest systems. 28 refs., 4 figs., 6 tabs

New York City Energy-Water Integrated Planning: A Pilot Study

Energy Technology Data Exchange (ETDEWEB)

Bhatt,V.; Crosson, K. M.; Horak, W.; Reisman, A.

2008-12-16

The New York City Energy-Water Integrated Planning Pilot Study is one of several projects funded by Sandia National Laboratories under the U.S. Department of Energy Energy-Water Nexus Program. These projects are intended to clarify some key issues and research needs identified during the Energy-Water Nexus Roadmapping activities. The objectives of the New York City Pilot Project are twofold: to identify energy-water nexus issues in an established urban area in conjunction with a group of key stakeholders and to define and apply an integrated energy and water decision support tool, as proof-of-concept, to one or more of these issues. During the course of this study, the Brookhaven National Laboratory project team worked very closely with members of a Pilot Project Steering Committee. The Steering Committee members brought a breadth of experience across the energy, water and climate disciplines, and all are well versed in the particular issues faced by an urban environment, and by New York City in particular. The first task was to identify energy-water issues of importance to New York City. This exercise was followed by discussion of the qualities and capabilities that an ideal decision support tool should display to address these issues. The decision was made to start with an existing energy model, the New York City version of the MARKAL model, developed originally at BNL and now used globally by many groups for energy analysis. MARKAL has the virtue of being well-vetted, transparent, and capable of calculating 'material' flows, such as water use by the energy system and energy requirements of water technology. The Steering Committee members defined five scenarios of interest, representing a broad spectrum of New York City energy-water issues. Brookhaven National Laboratory researchers developed a model framework (Water-MARKAL) at the desired level of detail to address the scenarios, and then attempted to gather the New York City-specific information

Community Phylogenetics: Assessing Tree Reconstruction Methods and the Utility of DNA Barcodes

Science.gov (United States)

Boyle, Elizabeth E.; Adamowicz, Sarah J.

2015-01-01

Studies examining phylogenetic community structure have become increasingly prevalent, yet little attention has been given to the influence of the input phylogeny on metrics that describe phylogenetic patterns of co-occurrence. Here, we examine the influence of branch length, tree reconstruction method, and amount of sequence data on measures of phylogenetic community structure, as well as the phylogenetic signal (Pagel’s λ) in morphological traits, using Trichoptera larval communities from Churchill, Manitoba, Canada. We find that model-based tree reconstruction methods and the use of a backbone family-level phylogeny improve estimations of phylogenetic community structure. In addition, trees built using the barcode region of cytochrome c oxidase subunit I (COI) alone accurately predict metrics of phylogenetic community structure obtained from a multi-gene phylogeny. Input tree did not alter overall conclusions drawn for phylogenetic signal, as significant phylogenetic structure was detected in two body size traits across input trees. As the discipline of community phylogenetics continues to expand, it is important to investigate the best approaches to accurately estimate patterns. Our results suggest that emerging large datasets of DNA barcode sequences provide a vast resource for studying the structure of biological communities. PMID:26110886

When a tree falls: Controls on wood decay predict standing dead tree fall and new risks in changing forests

Science.gov (United States)

Brad Oberle; Kiona Ogle; Amy E. Zanne; Christopher W. Woodall

2018-01-01

When standing dead trees (snags) fall, they have major impacts on forest ecosystems. Snag fall can redistribute wildlife habitat and impact public safety, while governing important carbon (C) cycle consequences of tree mortality because ground contact accelerates C emissions during deadwood decay. Managing the consequences of altered snag dynamics in changing forests...

Canopy soil bacterial communities altered by severing host tree limbs

Directory of Open Access Journals (Sweden)

Cody R. Dangerfield

2017-09-01

Full Text Available Trees of temperate rainforests host a large biomass of epiphytic plants, which are associated with soils formed in the forest canopy. Falling of epiphytic material results in the transfer of carbon and nutrients from the canopy to the forest floor. This study provides the first characterization of bacterial communities in canopy soils enabled by high-depth environmental sequencing of 16S rRNA genes. Canopy soil included many of the same major taxonomic groups of Bacteria that are also found in ground soil, but canopy bacterial communities were lower in diversity and contained different operational taxonomic units. A field experiment was conducted with epiphytic material from six Acer macrophyllum trees in Olympic National Park, Washington, USA to document changes in the bacterial communities of soils associated with epiphytic material that falls to the forest floor. Bacterial diversity and composition of canopy soil was highly similar, but not identical, to adjacent ground soil two years after transfer to the forest floor, indicating that canopy bacteria are almost, but not completely, replaced by ground soil bacteria. Furthermore, soil associated with epiphytic material on branches that were severed from the host tree and suspended in the canopy contained altered bacterial communities that were distinct from those in canopy material moved to the forest floor. Therefore, the unique nature of canopy soil bacteria is determined in part by the host tree and not only by the physical environmental conditions associated with the canopy. Connection to the living tree appears to be a key feature of the canopy habitat. These results represent an initial survey of bacterial diversity of the canopy and provide a foundation upon which future studies can more fully investigate the ecological and evolutionary dynamics of these communities.

Rhizospheric microbial communities associated with wild and cultivated frankincense producing Boswellia sacra tree.

Directory of Open Access Journals (Sweden)

Abdul Latif Khan

Full Text Available Boswellia sacra, a frankincense producing endemic tree, has been well known for its cultural, religious and economic values. However, the tree has been least explored for the associated microsymbiota in the rhizosphere. The current study elucidates the fungal and bacterial communities of the rhizospheric regions of the wild and cultivated B. sacra tree populations through next generation sequencing. The sequence analysis showed the existence of 1006±8.9 and 60.6±3.1 operational taxonomic unit (OTUs for bacterial and fungal communities respectively. In fungal communities, five major phyla were found with significantly higher abundance of Ascomycota (60.3% in wild population and Basidiomycota (52% in cultivated tree rhizospheres. Among bacterial communities, 31 major phyla were found, with significant distribution of Actinobacteria in wild tree rhizospheres, whereas Proteobacteria and Acidobacteria were highly abundant in cultivated trees. The diversity and abundance of microbiome varied significantly depending upon soil characteristics of the three different populations. In addition, significantly higher glucosidases, cellulases and indole-3-acetic acid were found in cultivated tree's rhizospheres as compared to wild tree populations. for these plants to survive the harsh arid-land environmental conditions. The current study is a first comprehensive work and advances our knowledge about the core fungal and bacterial microbial microbiome associated with this economically important tree.

Predictors of mortality for juvenile trees in a residential urban-to-rural cohort in Worcester, MA

Science.gov (United States)

Arthur Elmes; John Rogan; Lara A. Roman; Christopher A. Williams; Samuel J. Ratick; David J. Nowak; Deborah G. Martin

2018-01-01

This paper explores predictors of juvenile tree mortality in a newly planted cohort in Worcester, MA, following an episode of large-scale tree removal necessitated by an Asian Longhorned Beetle (Anoplophora glabripennis, ALB) eradication program. Trees are increasingly seen as important providers of ecosystem services for urban areas, including:...

Host tree phenology affects vascular epiphytes at the physiological, demographic and community level

Science.gov (United States)

Einzmann, Helena J. R.; Beyschlag, Joachim; Hofhansl, Florian; Wanek, Wolfgang; Zotz, Gerhard

2015-01-01

The processes that govern diverse tropical plant communities have rarely been studied in life forms other than trees. Structurally dependent vascular epiphytes, a major part of tropical biodiversity, grow in a three-dimensional matrix defined by their hosts, but trees differ in their architecture, bark structure/chemistry and leaf phenology. We hypothesized that the resulting seasonal differences in microclimatic conditions in evergreen vs. deciduous trees would affect epiphytes at different levels, from organ physiology to community structure. We studied the influence of tree leaf phenology on vascular epiphytes on the Island of Barro Colorado, Panama. Five tree species were selected, which were deciduous, semi-deciduous or evergreen. The crowns of drought-deciduous trees, characterized by sunnier and drier microclimates, hosted fewer individuals and less diverse epiphyte assemblages. Differences were also observed at a functional level, e.g. epiphyte assemblages in deciduous trees had larger proportions of Crassulacean acid metabolism species and individuals. At the population level a drier microclimate was associated with lower individual growth and survival in a xerophytic fern. Some species also showed, as expected, lower specific leaf area and higher δ13C values when growing in deciduous trees compared with evergreen trees. As hypothesized, host tree leaf phenology influences vascular epiphytes at different levels. Our results suggest a cascading effect of tree composition and associated differences in tree phenology on the diversity and functioning of epiphyte communities in tropical lowland forests. PMID:25392188

Ectomycorrhizal fungal communities of native and non-native Pinus and Quercus species in a common garden of 35-year-old trees.

Science.gov (United States)

Trocha, Lidia K; Kałucka, Izabela; Stasińska, Małgorzata; Nowak, Witold; Dabert, Mirosława; Leski, Tomasz; Rudawska, Maria; Oleksyn, Jacek

2012-02-01

Non-native tree species have been widely planted or have become naturalized in most forested landscapes. It is not clear if native trees species collectively differ in ectomycorrhizal fungal (EMF) diversity and communities from that of non-native tree species. Alternatively, EMF species community similarity may be more determined by host plant phylogeny than by whether the plant is native or non-native. We examined these unknowns by comparing two genera, native and non-native Quercus robur and Quercus rubra and native and non-native Pinus sylvestris and Pinus nigra in a 35-year-old common garden in Poland. Using molecular and morphological approaches, we identified EMF species from ectomycorrhizal root tips and sporocarps collected in the monoculture tree plots. A total of 69 EMF species were found, with 38 species collected only as sporocarps, 18 only as ectomycorrhizas, and 13 both as ectomycorrhizas and sporocarps. The EMF species observed were all native and commonly associated with a Holarctic range in distribution. We found that native Q. robur had ca. 120% higher total EMF species richness than the non-native Q. rubra, while native P. sylvestris had ca. 25% lower total EMF species richness than non-native P. nigra. Thus, across genera, there was no evidence that native species have higher EMF species diversity than exotic species. In addition, we found a higher similarity in EMF communities between the two Pinus species than between the two Quercus species. These results support the naturalization of non-native trees by means of mutualistic associations with cosmopolitan and novel fungi.

The Multilingual Apple: Languages in New York City. Second Edition.

Science.gov (United States)

Garcia, Ofelia, Ed.; Fishman, Joshua A., Ed.

This collection of papers tells the story of how languages other than English have contributed to making New York City a culturally vibrant and linguistically diverse city. Part 1, "Introduction to the Multilingual Apple," features "New York's Multilingualism: World Languages and Their Role in a U.S. City" (Ofelia Garcia). Part…

Trends in Birth Rates: New York City 1970-1995.

Science.gov (United States)

Finkel, Madelon L.; Elkin, Elena

2001-01-01

Examined teen birth rates in New York City health districts over 25 years, noting ethnic variations. Data from Department of Health vital statistics indicated that the decline in the birth rate among New York City teens was most significant in health districts populated predominantly by blacks. There were substantial decreases among older teens…

A new tree classification system for southern hardwoods

Science.gov (United States)

James S. Meadows; Daniel A. Jr. Skojac

2008-01-01

A new tree classification system for southern hardwoods is described. The new system is based on the Putnam tree classification system, originally developed by Putnam et al., 1960, Management ond inventory of southern hardwoods, Agriculture Handbook 181, US For. Sew., Washington, DC, which consists of four tree classes: (1) preferred growing stock, (2) reserve growing...

Deaths in New York City Jails, 2001–2009

Science.gov (United States)

Brittain, Joan; Axelrod, George

2013-01-01

Approximately 90 000 inmates are admitted annually to the New York City jail system, many of whom require a high level of medical or mental health services. According to our analysis of deaths in custody from 2001 to 2009, crude death rates have dropped significantly despite the increasing age of the population. Falling HIV-related mortality appears to contribute to this change. Other observations include low rates of suicide across all 9 years and increasing age of the population in recent years. PMID:23409900

Food insecurity and obesity in New York City primary care clinics.

Science.gov (United States)

Karnik, Arati; Foster, Byron Alexander; Mayer, Victoria; Pratomo, Vanessa; McKee, Diane; Maher, Stacia; Campos, Giselle; Anderson, Matthew

2011-07-01

Hunger continues to be a problem in New York City; paradoxically, the city also has disproportionally high rates of diabetes and obesity. Some research suggests that food insecurity leads to obesity. We undertook a cross-sectional "card study" in which doctors working at 8 New York City area primary care practices administered a brief, anonymous survey to patients they saw during clinic sessions. The survey included a 2-question food insecurity screen and questions about enrollment in nutrition assistance programs. Height and weight were also measured at the visit. Cards were completed for 558 patients (65.1% female; 74.7% adults; 78.5% conducted in English). Fifty-five percent of patients were receiving some form of food assistance. More than half of patients (51.7%) reported some degree of food insecurity. Of adult participants, 21.8% had normal weight, 29.1% were overweight, and 48.2% were obese. Food insecurity was significantly associated with increasing body mass index in women not receiving food assistance. There was no significant association between body mass index and food insecurity in children. In an urban population, overweight and obesity are very common as is food insecurity. We found an association between food insecurity and obesity only among women not receiving food assistance suggesting a possible protective role for food assistance. Providers should consider food insecurity in similar populations when trying to address obesity.

Mean Streets: An analysis on street level pollution in NYC

Science.gov (United States)

Parker, G.

2017-12-01

The overarching objective of this study is to quantify the spatial and temporal variability in particulatematter concentration (PM 2.5) along crowded streets in New York City. Due to their fine size and lowdensity PM 2.5 stays longer in the atmosphere and could bypass human nose and throat and penetratedeep in to the lungs and even enter the circulatory system. PM 2.5 is a by-product of automobilecombustion and is a primary cause of respiratory malfunction in NYC. The study would monitor streetlevel concentration of PM2.5 across three different routes that witness significant pedestrian traffic;observations will be conducted along these three routes at different time periods. The study will use theAirBeam community air quality monitor. The monitor tracks PM 2.5 concentration along with GPS, airtemperature and relative humidity. The surface level concentration monitored by AirBeam will becompared with atmospheric concentration of PM 2.5 that are monitored at the NOAA CREST facility onCCNY campus. The lower atmospheric values will be correlated with street level values to assess thevalidity of using of lower atmospheric values to predict street level concentrations. The street levelconcentration will be compared to the air quality forecasted by the New York Department ofEnvironment Conservation to estimate its accuracy and applicability.

Measuring and analyzing urban tree cover

Science.gov (United States)

David J. Nowak; Rowan A. Rowntree; E. Gregory McPherson; Susan M. Sisinni; Esther R. Kirkmann; Jack C. Stevens

1996-01-01

Measurement of city tree cover can aid in urban vegetation planning, management, and research by revealing characteristics of vegetation across a city. Urban tree cover in the United States ranges from 0.4% in Lancaster, California, to 55% in Baton Rouge, Louisiana. Two important factors that affect the amount of urban tree cover are the natural environment and land...

Penalized regression techniques for prediction: a case study for predicting tree mortality using remotely sensed vegetation indices

NARCIS (Netherlands)

Lazaridis, D.C.; Verbesselt, J.; Robinson, A.P.

2011-01-01

Constructing models can be complicated when the available fitting data are highly correlated and of high dimension. However, the complications depend on whether the goal is prediction instead of estimation. We focus on predicting tree mortality (measured as the number of dead trees) from change

The ghosts of trees past: savanna trees create enduring legacies in plant species composition.

Science.gov (United States)

Stahlheber, Karen A; Crispin, Kimberly L; Anton, Cassidy; D'Antonio, Carla M

2015-09-01

Isolated trees in savannas worldwide are known to modify their local environment and interact directly with neighboring plants. Less is known about how related tree species differ in their impacts on surrounding communities, how the effects of trees vary between years, and how composition might change following loss of the tree. To address these knowledge gaps, we explored the following questions: How do savanna trees influence the surrounding composition of herbaceous plants? Is the influence of trees consistent across different species and years? How does this change following the death of the tree? We surveyed herbaceous species composition and environmental attributes surrounding living and dead evergreen and deciduous Quercus trees in California (USA) savannas across several years that differed in their total precipitation. Oak trees of all species created distinct, homogenous understory communities dominated by exotic grasses across several sites. The composition of the low-diversity understory communities showed less interannual variation than open grassland, despite a two-fold difference in precipitation between the driest and wettest year. Vegetation composition was correlated with variation in soil properties, which were strongly affected by trees. Oaks also influenced the communities beyond the edge of the crown, but this depended on site and oak species. Low-diversity understory communities persisted up to 43 years following the death of the tree. A gradual decline in the effect of trees on the physical, environment following death did not result in vegetation becoming more similar to open grassland over time. The presence of long-lasting legacies of past tree crowns highlights the difficulty of assigning control of the current distribution of herbaceous species in grassland to their contemporary environment.

Biotic mortality factors affecting emerald ash borer (Agrilus planipennis) are highly dependent on life stage and host tree crown condition.

Science.gov (United States)

Jennings, D E; Duan, J J; Shrewsbury, P M

2015-10-01

Emerald ash borer (EAB), Agrilus planipennis, is a serious invasive forest pest in North America responsible for killing tens to hundreds of millions of ash trees since it was accidentally introduced in the 1990 s. Although host-plant resistance and natural enemies are known to be important sources of mortality for EAB in Asia, less is known about the importance of different sources of mortality at recently colonized sites in the invaded range of EAB, and how these relate to host tree crown condition. To further our understanding of EAB population dynamics, we used a large-scale field experiment and life-table analyses to quantify the fates of EAB larvae and the relative importance of different biotic mortality factors at 12 recently colonized sites in Maryland. We found that the fates of larvae were highly dependent on EAB life stage and host tree crown condition. In relatively healthy trees (i.e., with a low EAB infestation) and for early instars, host tree resistance was the most important mortality factor. Conversely, in more unhealthy trees (i.e., with a moderate to high EAB infestation) and for later instars, parasitism and predation were the major sources of mortality. Life-table analyses also indicated how the lack of sufficient levels of host tree resistance and natural enemies contribute to rapid population growth of EAB at recently colonized sites. Our findings provide further evidence of the mechanisms by which EAB has been able to successfully establish and spread in North America.

Tree condition and mortality following defoliation by the gypsy moth

Science.gov (United States)

Robert W. Campbell; Harry T. Valentine; Harry T. Valentine

1972-01-01

Relationships between expected defoliation and the subsequent condition and mortality rate among the defoliated trees are almost always important factors in deciding if, when, and where to take control action against a defoliator such as the gypsy moth, Porthetria dispar (L. )

The Urban Tree as a Tool to Mitigate the Urban Heat Island in Mexico City: A Simple Phenomenological Model.

Science.gov (United States)

Ballinas, Mónica; Barradas, Víctor L

2016-01-01

The urban heat island (UHI) is mainly a nocturnal phenomenon, but it also appears during the day in Mexico City. The UHI may affect human thermal comfort, which can influence human productivity and morbidity in the spring/summer period. A simple phenomenological model based on the energy balance was developed to generate theoretical support of UHI mitigation in Mexico City focused on the latent heat flux change by increasing tree coverage to reduce sensible heat flux and air temperature. Half-hourly data of the urban energy balance components were generated in a typical residential/commercial neighborhood of Mexico City and then parameterized using easily measured variables (air temperature, humidity, pressure, and visibility). Canopy conductance was estimated every hour in four tree species, and transpiration was estimated using sap flow technique and parameterized by the envelope function method. Averaged values of net radiation, energy storage, and sensible and latent heat flux were around 449, 224, 153, and 72 W m, respectively. Daily tree transpiration ranged from 3.64 to 4.35 Ld. To reduce air temperature by 1°C in the studied area, 63 large would be required per hectare, whereas to reduce the air temperature by 2°C only 24 large trees would be required. This study suggests increasing tree canopy cover in the city cannot mitigate UHI adequately but requires choosing the most appropriate tree species to solve this problem. It is imperative to include these types of studies in tree selection and urban development planning to adequately mitigate UHI. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

A multi-species synthesis of physiological mechanisms in drought-induced tree mortality

Energy Technology Data Exchange (ETDEWEB)

Adams, Henry D.; Zeppel, Melanie J. B.; Anderegg, William R. L.; Hartmann, Henrik; Landhäusser, Simon M.; Tissue, David T.; Huxman, Travis E.; Hudson, Patrick J.; Franz, Trenton E.; Allen, Craig D.; Anderegg, Leander D. L.; Barron-Gafford, Greg A.; Beerling, David J.; Breshears, David D.; Brodribb, Timothy J.; Bugmann, Harald; Cobb, Richard C.; Collins, Adam D.; Dickman, L. Turin; Duan, Honglang; Ewers, Brent E.; Galiano, Lucía; Galvez, David A.; Garcia-Forner, Núria; Gaylord, Monica L.; Germino, Matthew J.; Gessler, Arthur; Hacke, Uwe G.; Hakamada, Rodrigo; Hector, Andy; Jenkins, Michael W.; Kane, Jeffrey M.; Kolb, Thomas E.; Law, Darin J.; Lewis, James D.; Limousin, Jean-Marc; Love, David M.; Macalady, Alison K.; Martínez-Vilalta, Jordi; Mencuccini, Maurizio; Mitchell, Patrick J.; Muss, Jordan D.; O’Brien, Michael J.; O’Grady, Anthony P.; Pangle, Robert E.; Pinkard, Elizabeth A.; Piper, Frida I.; Plaut, Jennifer A.; Pockman, William T.; Quirk, Joe; Reinhardt, Keith; Ripullone, Francesco; Ryan, Michael G.; Sala, Anna; Sevanto, Sanna; Sperry, John S.; Vargas, Rodrigo; Vennetier, Michel; Way, Danielle A.; Xu, Chonggang; Yepez, Enrico A.; McDowell, Nate G.

2017-08-07

Widespread tree mortality associated with drought has been observed on all forested continents, and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere-atmosphere interactions of carbon, water, and energy balance, and is poorly represented in dynamic vegetation models. Reducing uncertainty requires improved mortality projections founded on robust physiological processes. However, the proposed mechanisms of drought-induced mortality, including hydraulic failure and carbon starvation, are unresolved. A growing number of empirical studies have investigated these mechanisms, but data have not been consistently analyzed across species and biomes using a standardized physiological framework. Here we show that xylem hydraulic failure was ubiquitous across multiple tree taxa at drought-induced mortality. All species assessed had 60% or greater loss of xylem hydraulic conductivity, consistent with proposed theoretical and modelled survival thresholds. We found diverse responses in non-structural carbohydrates at mortality, indicating that evidence supporting carbon starvation was not universal. Reduced non-structural carbohydrates were more common for gymnosperms than angiosperms, associated with xylem hydraulic vulnerability, and may have a role in hydraulic deterioration. The consistent Our finding that across species of hydraulic failure at drought-induced mortality was persistent across species indicates that substantial improvement in vegetation modelling can be achieved using thresholds in hydraulic function.

A multi-species synthesis of physiological mechanisms in drought-induced tree mortality.

Science.gov (United States)

Adams, Henry D; Zeppel, Melanie J B; Anderegg, William R L; Hartmann, Henrik; Landhäusser, Simon M; Tissue, David T; Huxman, Travis E; Hudson, Patrick J; Franz, Trenton E; Allen, Craig D; Anderegg, Leander D L; Barron-Gafford, Greg A; Beerling, David J; Breshears, David D; Brodribb, Timothy J; Bugmann, Harald; Cobb, Richard C; Collins, Adam D; Dickman, L Turin; Duan, Honglang; Ewers, Brent E; Galiano, Lucía; Galvez, David A; Garcia-Forner, Núria; Gaylord, Monica L; Germino, Matthew J; Gessler, Arthur; Hacke, Uwe G; Hakamada, Rodrigo; Hector, Andy; Jenkins, Michael W; Kane, Jeffrey M; Kolb, Thomas E; Law, Darin J; Lewis, James D; Limousin, Jean-Marc; Love, David M; Macalady, Alison K; Martínez-Vilalta, Jordi; Mencuccini, Maurizio; Mitchell, Patrick J; Muss, Jordan D; O'Brien, Michael J; O'Grady, Anthony P; Pangle, Robert E; Pinkard, Elizabeth A; Piper, Frida I; Plaut, Jennifer A; Pockman, William T; Quirk, Joe; Reinhardt, Keith; Ripullone, Francesco; Ryan, Michael G; Sala, Anna; Sevanto, Sanna; Sperry, John S; Vargas, Rodrigo; Vennetier, Michel; Way, Danielle A; Xu, Chonggang; Yepez, Enrico A; McDowell, Nate G

2017-09-01

Widespread tree mortality associated with drought has been observed on all forested continents and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere-atmosphere interactions of carbon, water and energy balance, and is poorly represented in dynamic vegetation models. Reducing uncertainty requires improved mortality projections founded on robust physiological processes. However, the proposed mechanisms of drought-induced mortality, including hydraulic failure and carbon starvation, are unresolved. A growing number of empirical studies have investigated these mechanisms, but data have not been consistently analysed across species and biomes using a standardized physiological framework. Here, we show that xylem hydraulic failure was ubiquitous across multiple tree taxa at drought-induced mortality. All species assessed had 60% or higher loss of xylem hydraulic conductivity, consistent with proposed theoretical and modelled survival thresholds. We found diverse responses in non-structural carbohydrate reserves at mortality, indicating that evidence supporting carbon starvation was not universal. Reduced non-structural carbohydrates were more common for gymnosperms than angiosperms, associated with xylem hydraulic vulnerability, and may have a role in reducing hydraulic function. Our finding that hydraulic failure at drought-induced mortality was persistent across species indicates that substantial improvement in vegetation modelling can be achieved using thresholds in hydraulic function.

A multi-species synthesis of physiological mechanisms in drought-induced tree mortality

Science.gov (United States)

Adams, Henry D.; Zeppel, Melanie; Anderegg, William R.L.; Hartmann, Henrik; Landhäusser, Simon M.; Tissue, David T.; Huxman, Travis E.; Hudson, Patrick J.; Franz, Trenton E.; Allen, Craig D.; Anderegg, Leander D. L.; Barron-Gafford, Greg A.; Beerling, David; Breshears, David D.; Brodribb, Timothy J.; Bugmann, Harald; Cobb, Richard C.; Collins, Adam D.; Dickman, L. Turin; Duan, Honglang; Ewers, Brent E.; Galiano, Lucia; Galvez, David A.; Garcia-Forner, Núria; Gaylord, Monica L.; Germino, Matthew J.; Gessler, Arthur; Hacke, Uwe G.; Hakamada, Rodrigo; Hector, Andy; Jenkins, Michael W.; Kane, Jeffrey M.; Kolb, Thomas E.; Law, Darin J.; Lewis, James D.; Limousin, Jean-Marc; Love, David; Macalady, Alison K.; Martinez-Vilalta, Jordi; Mencuccini, Maurizio; Mitchell, Patrick J.; Muss, Jordan D.; O'Brien, Michael J.; O'Grady, Anthony P.; Pangle, Robert E.; Pinkard, Elizabeth A.; Piper, Frida I.; Plaut, Jennifer; Pockman, William T.; Quirk, Joe; Reinhardt, Keith; Ripullone, Francesco; Ryan, Michael G.; Sala, Anna; Sevanto, Sanna; Sperry, John S.; Vargas, Rodrigo; Vennetier, Michel; Way, Danielle A.; Wu, Chonggang; Yepez, Enrico A.; McDowell, Nate G.

2017-01-01

Widespread tree mortality associated with drought has been observed on all forested continents and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere–atmosphere interactions of carbon, water and energy balance, and is poorly represented in dynamic vegetation models. Reducing uncertainty requires improved mortality projections founded on robust physiological processes. However, the proposed mechanisms of drought-induced mortality, including hydraulic failure and carbon starvation, are unresolved. A growing number of empirical studies have investigated these mechanisms, but data have not been consistently analysed across species and biomes using a standardized physiological framework. Here, we show that xylem hydraulic failure was ubiquitous across multiple tree taxa at drought-induced mortality. All species assessed had 60% or higher loss of xylem hydraulic conductivity, consistent with proposed theoretical and modelled survival thresholds. We found diverse responses in non-structural carbohydrate reserves at mortality, indicating that evidence supporting carbon starvation was not universal. Reduced non-structural carbohydrates were more common for gymnosperms than angiosperms, associated with xylem hydraulic vulnerability, and may have a role in reducing hydraulic function. Our finding that hydraulic failure at drought-induced mortality was persistent across species indicates that substantial improvement in vegetation modelling can be achieved using thresholds in hydraulic function.

Tree-growth analyses to estimate tree species' drought tolerance.

Science.gov (United States)

Eilmann, Britta; Rigling, Andreas

2012-02-01

Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree species' potential for surviving future aggravated environmental conditions is rather demanding. The aim of this study was to find a tree-ring-based method suitable for identifying very drought-tolerant species, particularly potential substitute species for Scots pine (Pinus sylvestris L.) in Valais. In this inner-Alpine valley, Scots pine used to be the dominating species for dry forests, but today it suffers from high drought-induced mortality. We investigate the growth response of two native tree species, Scots pine and European larch (Larix decidua Mill.), and two non-native species, black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii), to drought. This involved analysing how the radial increment of these species responded to increasing water shortage (abandonment of irrigation) and to increasingly frequent drought years. Black pine and Douglas fir are able to cope with drought better than Scots pine and larch, as they show relatively high radial growth even after irrigation has been stopped and a plastic growth response to drought years. European larch does not seem to be able to cope with these dry conditions as it lacks the ability to recover from drought years. The analysis of trees' short-term response to extreme climate events seems to be the most promising and suitable method for detecting how tolerant a tree species is towards drought. However, combining all the methods used in this study provides a complete picture of how water shortage could limit species.

Microbial sewage contamination associated with Superstorm Sandy flooding in New York City

Science.gov (United States)

O'Mullan, G.; Dueker, M.; Sahajpal, R.; Juhl, A. R.

2013-05-01

The lower Hudson River Estuary commonly experiences degraded water quality following precipitation events due to the influence of combined sewer overflows. During Super-storm Sandy large scale flooding occurred in many waterfront areas of New York City, including neighborhoods bordering the Gowanus Canal and Newtown Creek Superfund sites known to frequently contain high levels of sewage associated bacteria. Water, sediment, and surface swab samples were collected from Newtown Creek and Gowanus Canal flood impacted streets and basements in the days following the storm, along with samples from the local waterways. Samples were enumerated for the sewage indicating bacterium, Enterococcus, and DNA was extracted and amplified for 16S ribosomal rRNA gene sequence analysis. Waterways were found to have relatively low levels of sewage contamination in the days following the storm. In contrast, much higher levels of Enterococci were detected in basement and storm debris samples and these bacteria were found to persist for many weeks in laboratory incubations. These data suggest that substantial sewage contamination occurred in some flood impacted New York City neighborhoods and that the environmental persistence of flood water associated microbes requires additional study and management attention.

Declining urban and community tree cover in the United States

Science.gov (United States)

David J. Nowak; Eric J. Greenfield

2018-01-01

Paired aerial photographs were interpreted to assess recent changes (c. 2009–2014) in tree, impervious and other cover types within urban/community and urban land in all 50 United States and the District of Columbia. National results indicate that tree cover in urban/community areas of the United States is on the decline at a rate of about 175,000 acres per year, which...

Widespread increase of tree mortality rates in the western United States

Science.gov (United States)

Phillip J. van Mantgem; Nathan L. Stephenson; John C. Byrne; Lori D. Daniels; Jerry F. Franklin; Peter Z. Fule; Mark E. Harmon; Andrew J. Larson; Jeremy M. Smith; Alan H. Taylor; Thomas T. Veblen

2009-01-01

Persistent changes in tree mortality rates can alter forest structure, composition, and ecosystem services such as carbon sequestration. Our analyses of longitudinal data from unmanaged old forests in the western United States showed that background (noncatastrophic) mortality rates have increased rapidly in recent decades, with doubling periods ranging from 17 to 29...

Using ROC curves to compare neural networks and logistic regression for modeling individual noncatastrophic tree mortality

Science.gov (United States)

Susan L. King

2003-01-01

The performance of two classifiers, logistic regression and neural networks, are compared for modeling noncatastrophic individual tree mortality for 21 species of trees in West Virginia. The output of the classifier is usually a continuous number between 0 and 1. A threshold is selected between 0 and 1 and all of the trees below the threshold are classified as...

A Global Perspective on Warmer Droughts as a Key Driver of Forest Disturbances and Tree Mortality (Invited)

Science.gov (United States)

Allen, C. D.

2013-12-01

Recent global warming, in concert with episodic droughts, is causing elevated levels of both chronic and acute forest water stress across large regions. Such increases in water stress affect forest dynamics in multiple ways, including by amplifying the incidence and severity of many significant forest disturbances, particularly drought-induced tree mortality, wildfire, and outbreaks of damaging insects and diseases. Emerging global-scale patterns of drought-related forest die-off are presented, including a newly updated map overview of documented drought- and heat-induced tree mortality events from around the world, demonstrating the vulnerability of all major forest types to forest drought stress, even in typically wet environments. Comparative patterns of drought stress and associated forest disturbances are reviewed for several regions (southwestern Australia, Inner Asia, western North America, Mediterranean Basin), including interactions among climate and various disturbance processes. From the Southwest USA, research is presented that derives a tree-ring-based Forest Drought Stress Index (FDSI) for the most regionally-widespread conifer species (Pinus edulis, Pinus ponderosa, and Pseudotsuga menziesii), demonstrating recent escalation of FDSI to extreme levels relative to the past 1000 years, due to both drought and especially warming. This new work further highlights strong correlations between drought stress and amplified forest disturbances (fire, bark beetle outbreaks), and projects that by CE 2050 anticipated regional warming will cause mean FDSI values to reach historically unprecedented levels that may exceed thresholds for the survival of current tree species in large portions of their current range in the Southwest. Similar patterns of recent climate-amplified forest disturbance risk are apparent from a variety of relatively dry regions across this planet, and given climate projections for substantially warmer temperatures and greater drought stress

Mapping resilience not risk: Turning the tide in New York City and Jamaica Bay

Science.gov (United States)

Parris, A. S.; Sanderson, E. W.

2015-12-01

Resilience in urban coastal areas is affected by actions at multiple levels from individuals to community groups to city, state and federal governments. At any level, actions can be a response to immediate hazards (e.g. flooding of coastal homes) or long-term drivers of change (e.g. sea level rise). Jamaica Bay, a highly urbanized estuary within New York City, exemplifies the Nation's coastal zone challenges. Prior to Hurricane Sandy, city, state, and federal governments had made the estuary a major focal point for habitat restoration, improvements to public access and outdoor recreation, and sustainable development. Sandy caused the highest flood level in the recorded history of New York City, eventually claiming 44 lives and costing over $19 billion. Electrical system failure caused four of NYCs wastewater pollution control plants to shutdown, discharging untreated sewage into Jamaica Bay. The Sea Level Rise Tool for Sandy Recovery (the Tool), a flood mapping tool developed by several government agencies including FEMA, NYC, and the Executive Branch, integrated science from the National Flood Insurance Program and the New York City Panel on Climate Change (NPCC). While compound flooding hazards (stormwater plus coastal flooding) remain an important uncertainty, the Tool and subsequent NPCC mapping efforts provide sufficient evidence for science-based discourse around coastal flood risks in Jamaica Bay. But toward what outcome? Coastal flood risk reduction measures and other management actions are managed within existing regulatory frameworks. Disaster relief funds appropriated by Congress in the immediate aftermath of Sandy have provided critical resources to the Jamaica Bay region. However, the challenge now is to transition from the short-term response to long-term resilience planning, a challenge which requires new institutional capacity. This transition to resilience planning and implementation is not only critical in New York City, but in other coastal

Influence of trees on the dispersion of pollutants in an urban street canyon - experimental investigation of the flow and concentration field

NARCIS (Netherlands)

Gromke, C.B.; Ruck, B.

2007-01-01

Flow field and concentration measurements have been performed in an idealized model of an urban street canyon with one row of trees arranged along the center axis. The model was set up in an atmospheric boundary layer wind tunnel and the approach flow was directed perpendicular to the street axis. A

[Impact of atmospheric total suspended particulate pollution on photosynthetic parameters of street mango trees in Xiamen City].

Science.gov (United States)

Yu, Yu-xian; Chen, Jin-sheng; Ren, Yin; Li, Fang-yi; Cui, Sheng-hui

2010-05-01

With the development of urbanization, total suspended particulate (TSP) pollution is getting serious, and the normal physiological processes of urban vegetation are profoundly affected while adsorbing and purifying the particulates. In this study, four areas were selected, i.e., Tingxi reservoir (clean control area), Xiamen University (cultural and educational area), Xianyue (business area), and Haicang (industrial area), with their atmospheric TSP concentrations and the photosynthetic parameters of street Mango (Mangifera indica) trees monitored in April and May, 2009. The daily average concentration of TSP in Tingxi, Xiamen University, Xianyue, and Haicang was 0.061, 0.113, 0.120 and 0.205 mg x m(-3), respectively, and the impact of TSP stress on M. indica was in the sequence of Haicang > Xianyue > Xiamen University > Tingxi. TSP pollution negatively affected the net photosynthetic rate, stomatal conductance, and transpiration rate of M. indica, and induced intercellular CO2 concentration changed significantly. High TSP concentration could cause the decline of net photosynthetic rate via stomatal limitation.

Comparison of outpatient medically attended and community-level influenza-like illness-New York City, 2013-2015.

Science.gov (United States)

Russell, Kate E; Fowlkes, Ashley; Stockwell, Melissa S; Vargas, Celibell Y; Saiman, Lisa; Larson, Elaine L; LaRussa, Philip; Di Lonardo, Steve; Popowich, Michael; St George, Kirsten; Steffens, Andrea; Reed, Carrie

2018-05-01

Surveillance of influenza-like illness (ILI) in the United States is primarily conducted through medical settings despite a significant burden of non-medically attended ILI. To assess consistency between surveillance for respiratory viruses in outpatient and community settings using ILI surveillance from the Centers for Disease Control and Prevention Influenza Incidence Surveillance Project (IISP) and the Mobile Surveillance for Acute Respiratory Infections (ARI) and Influenza-Like Illness in the Community (MoSAIC) Study. The Influenza Incidence Surveillance Project conducts ILI surveillance in 3 primary care clinics in New York City, and MoSAIC conducts community-based ILI/ARI surveillance through text messaging among a cohort of New York City residents. Both systems obtain respiratory specimens from participants with ILI/ARI and test for multiple pathogens. We conducted a retrospective review of ILI cases in IISP and MoSAIC from January 2013 to May 2015 with descriptive analyses of clinical and laboratory data. Five-hundred twelve MoSAIC and 669 IISP participants met an ILI criteria (fever with cough or sore throat) and were included. Forty percent of MoSAIC participants sought care; the majority primary care. Pathogens were detected in 63% of MoSAIC and 70% of IISP cases. The relative distribution of influenza and other respiratory viruses detected was similar; however, there were statistically significant differences in the frequency that were not explained by care seeking. Outpatient and community-based surveillance in the one found similar timing and relative distribution of respiratory viruses, but community surveillance in a single neighborhood may not fully capture the variations in ILI etiology that occur more broadly. Published 2018. This article is a U.S. Government work and is in the public domain in the USA. Influenza and Other Respiratory Viruses published by John Wiley & Sons Ltd.

A Case-Only Study of Vulnerability to Heat Wave-Related Mortality in New York City (2000-2011).

Science.gov (United States)

Madrigano, Jaime; Ito, Kazuhiko; Johnson, Sarah; Kinney, Patrick L; Matte, Thomas

2015-07-01

As a result of climate change, the frequency of extreme temperature events is expected to increase, and such events are associated with increased morbidity and mortality. Vulnerability patterns, and corresponding adaptation strategies, are most usefully conceptualized at a local level. We used a case-only analysis to examine subject and neighborhood characteristics that modified the association between heat waves and mortality. All deaths of New York City residents from 2000 through 2011 were included in this analysis. Meteorological data were obtained from the National Climatic Data Center. Modifying characteristics were obtained from the death record and geographic data sets. A total of 234,042 adult deaths occurred during the warm season of our study period. Compared with other warm-season days, deaths during heat waves were more likely to occur in black (non-Hispanic) individuals than other race/ethnicities [odds ratio (OR) = 1.08; 95% CI: 1.03, 1.12], more likely to occur at home than in institutions and hospital settings (OR = 1.11; 95% CI: 1.06, 1.16), and more likely among those living in census tracts that received greater public assistance (OR = 1.05; 95% CI: 1.01, 1.09). Finally, deaths during heat waves were more likely among residents in areas of the city with higher relative daytime summer surface temperature and less likely among residents living in areas with more green space. Mortality during heat waves varies widely within a city. Understanding which individuals and neighborhoods are most vulnerable can help guide local preparedness efforts.

New algorithm to detect modules in a fault tree for a PSA

International Nuclear Information System (INIS)

Jung, Woo Sik

2015-01-01

A module or independent subtree is a part of a fault tree whose child gates or basic events are not repeated in the remaining part of the fault tree. Modules are necessarily employed in order to reduce the computational costs of fault tree quantification. This paper presents a new linear time algorithm to detect modules of large fault trees. The size of cut sets can be substantially reduced by replacing independent subtrees in a fault tree with super-components. Chatterjee and Birnbaum developed properties of modules, and demonstrated their use in the fault tree analysis. Locks expanded the concept of modules to non-coherent fault trees. Independent subtrees were manually identified while coding a fault tree for computer analysis. However, nowadays, the independent subtrees are automatically identified by the fault tree solver. A Dutuit and Rauzy (DR) algorithm to detect modules of a fault tree for coherent or non-coherent fault tree was proposed in 1996. It has been well known that this algorithm quickly detects modules since it is a linear time algorithm. The new algorithm minimizes computational memory and quickly detects modules. Furthermore, it can be easily implemented into industry fault tree solvers that are based on traditional Boolean algebra, binary decision diagrams (BDDs), or Zero-suppressed BDDs. The new algorithm employs only two scalar variables in Eqs. to that are volatile information. After finishing the traversal and module detection of each node, the volatile information is destroyed. Thus, the new algorithm does not employ any other additional computational memory and operations. It is recommended that this method be implemented into fault tree solvers for efficient probabilistic safety assessment (PSA) of nuclear power plants