996 resultados para Oak Bluffs


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Reconstructing the history of ambient levels of metals by using tree-ring chemistry is controversial. This controversy can be resolved in part through the use of selective microanalysis of individual wood cells. Using a combination of instrumental neutron activation analysis and secondary ion mass spectrometry, we have observed systematic inhomogeneity in the abundance of toxic metals (Cr, As, Cd, and Pb) within annual growth rings of Quercus rubra (red oak) and have characterized individual xylem members responsible for introducing micrometer-scale gradients in toxic metal abundances. These gradients are useful for placing constraints on both the magnitude and the mechanism of heavy metal translocation within growing wood. It should now be possible to test, on a metal-by-metal basis, the suitability of using tree-ring chemistries for deciphering long-term records of many environmental metals.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The process of seed dispersal of many animal-dispersed plants is frequently mediated by a small set of biotic agents. However, the contribution that each of these dispersers makes to the overall recruitment may differ largely, with important ecological and management implications for the population viability and dynamics of the species implied in these interactions. In this paper, we compared the relative contribution of two local guilds of scatter-hoarding animals with contrasting metabolic requirements and foraging behaviours (rodents and dung beetles) to the overall recruitment of two Quercus species co-occurring in the forests of southern Spain. For this purpose, we considered not only the quantity of dispersed seeds but also the quality of the seed dispersal process. The suitability for recruitment of the microhabitats where the seeds were deposited was evaluated in a multi-stage demographic approach. The highest rates of seed handling and predation occurred in those microhabitats located under shrubs, mostly due to the foraging activity of rodents. However, the probability of a seed being successfully cached was higher in microhabitats located beneath a tree canopy as a result of the feeding behaviour of beetles. Rodents and beetles showed remarkable differences in their effectiveness as local acorn dispersers. Quantitatively, rodents were much more important than beetles because they dispersed the vast majority of acorns. However, they were qualitatively less effective because they consumed a high proportion of them (over 95%), and seeds were mostly dispersed under shrubs, a less suitable microhabitat for short-term recruitment of the two oak species. Our findings demonstrate that certain species of dung beetles (such as Thorectes lusitanicus), despite being quantitatively less important than rodents, can act as effective local seed dispersers of Mediterranean oak species. Changes in the abundance of beetle populations could thus have profound implications for oak recruitment and community dynamics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This layer is a georeferenced raster image of the historic paper map entitled: For sale : Lawnton and Oak Lane building lots : twenty-second ward : estate of E. M. Davis, deceased. It was published by J.T. Jackson & Co. ca. 1900. Scale [ca. 1:528,000]. Covers the Oak Lane neighborhood of Philadelphia, Pennsylvania. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Pennsylvania South State Plane Coordinate System NAD83 (in Feet) (Fipszone 3702). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. Cadastral map showing buildings, property boundaries and dimensions, names of landowners, streets names, railroad line and station stops, and more. Relief is shown by countours and spot heights. Includes sales and advertisement notice. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection as part of the Imaging the Urban Environment project. Maps selected for this project represent major urban areas and cities of the world, at various time periods. These maps typically portray both natural and manmade features at a large scale. The selection represents a range of regions, originators, ground condition dates, scales, and purposes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This research explores the policy implications of the approval of three wind energy projects on the Oak Ridges Moraine, and their impact on the Coordinated Land Use Planning Review process. Specifically, it focuses on the involvement of First Nations and environmental non-governmental organizations (ENGOs). This research was conducted through analyzing submissions to the Coordinated Land Use Planning Review, related legislation and policy, Environmental Review Tribunal hearing documents, and interviews with key informants. This research culminates in a number of recommendations to the Coordinated Review informed by the analysis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Mode of access: Internet.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tree before 1858; boulder ca. 1883; bronze plaque 1904. In spring of 1858 the Class of 1858 named this oak (growing near center of campus) the Tappan Oak as a tribute to then Pres. Henry P. Tappan). Stone was given by the "Tappan Boys" (class of 58) and placed ca. 1883.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cover title.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Supt. of Docs. no.: E 1.20/2:0182

Relevância:

20.00% 20.00%

Publicador:

Resumo:

"March 15, 1963 [DTI Issuance Date]."