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Graeme P. Berlyn

Bio: Graeme P. Berlyn is an academic researcher from Yale University. The author has contributed to research in topics: Transpiration & Stomatal conductance. The author has an hindex of 35, co-authored 105 publications receiving 5420 citations. Previous affiliations of Graeme P. Berlyn include North Carolina State University & United States Forest Service.


Papers
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Journal ArticleDOI
TL;DR: This article evaluated the performance of these optical methods, which are based on the absorbance or reflectance of certain wavelengths of light by intact leaves, and found that the reflectance indices that performed best were not those most commonly used in the literature.
Abstract: Summary • Over the last decade, technological developments have made it possible to quickly and nondestructively assess, in situ, the chlorophyll (Chl) status of plants. We evaluated the performance of these optical methods, which are based on the absorbance or reflectance of certain wavelengths of light by intact leaves. • As our benchmark, we used standard extraction techniques to measure Chla, Chlb, and total Chl content of paper birch (Betula papyrifera) leaves. These values were compared with the nominal Chl index values obtained with two hand-held Chl absorbance meters and several reflectance indices correlated with foliar Chl. • The noninvasive optical methods all provided reliable estimates of relative leaf Chl. However, across the range of Chl contents studied (0.0004–0.0455 mg cm−2), some reflectance indices consistently out-performed the hand-held meters. Most importantly, the reflectance indices that performed best were not those most commonly used in the literature. • We report equations to convert from index values to actual Chl content, but caution that differences in leaf structure may necessitate species-specific calibration equations.

985 citations

Journal ArticleDOI
TL;DR: The use of biostimulant compounds in forestry and agriculture offers significant opportuni for farmers, according to findings from current university researc! and field trials as discussed by the authors, improving root and shoot growth, better stress resistance, better root growth potential, and reduction in nitrogen levels of fertilization are some of the possibilities that these compounds connote to sustainable agriculture.
Abstract: The use of biostimulant compounds in forestry and agriculture offers significant opportuni for farmers, according to findings from current university researc ! and field trials. Improved root and shoot growth, better stress resistance, better root growth potential, and reduction in nitrogen levels of fertilization are some of the possibilities that these compounds connote to sustainable agriculture.

222 citations

Journal ArticleDOI
TL;DR: Evidence of salivary secretions, tracks, and sheaths produced by A. tsugae in the plant similar to those produced by aphids and other adelgids in their host plants suggests that the intense effect of A. Tsugae on eastern hemlock may be caused by factors other than its food consumption, that is, a possible toxin effect, or altered host plant response to environmental conditions.
Abstract: Stylet bundle insertion site, path traveled, and feeding site were examined for the hemlock woolly adelgid, Adelges tsugae Annand, on needles from current and previous years of eastern hemlock, Tsuga canadensis Carriere. The stylet bundle is composed of 4 individual stylets—2 outer mandibular stylets and 2 inner maxillary stylets. A. tsugae inserts its stylet bundle on the adaxial side of eastern hemlock needles, proximal to the twig with respect to the leaf abscission layer. Insertions are primarily intracellular through epidermal cells. Once inserted, the stylet bundle then follows a mixed intracellular and intercellular pathway, the latter predominating, when penetrating the plant tissue to the feeding site, the xylem ray parenchyma cells. We observed evidence of salivary secretions, tracks, and sheaths produced by A. tsugae in the plant similar to those produced by aphids and other adelgids in their host plants. Unlike other adelgids studied, which feed on cortical parenchyma cells and on solutes from phloem of their spruce hosts, A. tsugae appears to feed only on storage cells, the parenchyma cells which comprise the xylem rays. This suggests that the intense effect of A. tsugae on eastern hemlock may be caused by factors other than its food consumption, that is, a possible toxin effect, or altered host plant response to environmental conditions.

214 citations

Journal ArticleDOI
TL;DR: Physiological and anatomical attribut-es of leaves were examined of three species of Quercus section Erythrobalanus to demonstrate the close association between anatomical adaptations and efficiency of physiological processes and elucidate the distribution patterns of the three quercus species across the forest topography in southern New England.
Abstract: Physiological and anatomical attribut-es of leaves were examined of three species of Quercus section Erythrobalanus All three species occur in moist temperate deciduous forests of eastern North America Seedlings of each species were grown in different light conditions for comparison The attributes measured were net photosynthesis, stomatal conductivity, blade and cuticle thickness, stomatal density, thickness of upper and lower epidermis, and thickness of palisade mesophyll The results generally demonstrate the close association between anatomical adaptations and efficiency of physiological processes; they also elucidate the distribution patterns of the three Quercus species across the forest topography in southern New England The most drought-tolerant and light-demanding species, Q velutina (Lam), exhibited the greatest leaf anatomical plasticity, the highest net photosynthesis in the different light conditions, and the lowest stomatal area per unit area of leaf The most drought-intolerant species, Q rubra (L), exhibited the least leaf anatomical plasticity, the lowest net photosynthesis in the different light conditions, and the highest stomatal area per unit area of leaf Quercus coccinea (Muenchh) usually exhibited values that were intermediate between Q rubra and Q velutina

192 citations


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01 Jan 2016
TL;DR: The modern applied statistics with s is universally compatible with any devices to read, and is available in the digital library an online access to it is set as public so you can download it instantly.
Abstract: Thank you very much for downloading modern applied statistics with s. As you may know, people have search hundreds times for their favorite readings like this modern applied statistics with s, but end up in harmful downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they cope with some harmful virus inside their laptop. modern applied statistics with s is available in our digital library an online access to it is set as public so you can download it instantly. Our digital library saves in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the modern applied statistics with s is universally compatible with any devices to read.

5,249 citations

Journal Article
TL;DR: In this article, the authors present a document, redatto, voted and pubblicato by the Ipcc -Comitato intergovernativo sui cambiamenti climatici - illustra la sintesi delle ricerche svolte su questo tema rilevante.
Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

4,187 citations

Journal ArticleDOI
21 Aug 2003-Nature
TL;DR: Stomatal morphology, distribution and behaviour respond to a spectrum of signals, from intracellular signalling to global climatic change, which results from a web of control systems reminiscent of a ‘scale-free’ network, whose untangling requires integrated approaches beyond those currently used.
Abstract: Stomata, the small pores on the surfaces of leaves and stalks, regulate the flow of gases in and out of leaves and thus plants as a whole. They adapt to local and global changes on all timescales from minutes to millennia. Recent data from diverse fields are establishing their central importance to plant physiology, evolution and global ecology. Stomatal morphology, distribution and behaviour respond to a spectrum of signals, from intracellular signalling to global climatic change. Such concerted adaptation results from a web of control systems, reminiscent of a 'scale-free' network, whose untangling requires integrated approaches beyond those currently used.

1,877 citations

Journal ArticleDOI
14 Jan 2016-Nature
TL;DR: Analysis of worldwide variation in six major traits critical to growth, survival and reproduction within the largest sample of vascular plant species ever compiled found that occupancy of six-dimensional trait space is strongly concentrated, indicating coordination and trade-offs.
Abstract: The authors found that the key elements of plant form and function, analysed at global scale, are largely concentrated into a two-dimensional plane indexed by the size of whole plants and organs on the one hand, and the construction costs for photosynthetic leaf area, on the other.

1,814 citations

Journal ArticleDOI
TL;DR: Spectral reflectance of maple, chestnut, wild vine and beech leaves in a wide range of pigment content and composition was investigated and it was shown that reciprocal reflectance (R lambda)-1 in the spectral range lambda related closely to the total chlorophyll content in leaves of all species.

1,667 citations