Download or read book the photosynthetic characteristics of saplings of eight canopy tree species in a disturbed neotropical rain forest written by and published by Bib. Orton IICA / CATIE. This book was released on with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Canopy Photosynthesis From Basics to Applications written by Kouki Hikosaka and published by Springer. This book was released on 2015-12-17 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last 30 years has seen the development of increasingly sophisticated models that quantify canopy carbon exchange. These models are now essential parts of larger models for prediction and simulation of crop production, climate change, and regional and global carbon dynamics. There is thus an urgent need for increasing expertise in developing, use and understanding of these models. This in turn calls for an advanced, yet easily accessible textbook that summarizes the “canopy science” and introduces the present and the future scientists to the theoretical background of the current canopy models. This book presents current knowledge of functioning of plant canopies, models and strategies employed to simulate canopy function, and the significance of canopy architecture, physiology and dynamics in ecosystems, landscape and biosphere.

Download or read book The Response of Tree Seedlings to Canopy Disturbance in an Amazonian Rain Forest written by S. B. Jennings and published by . This book was released on 1997 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study set out to explore the hypothesis that species richness of tropical rain forest is maintained by defferential responses of seedlings to varying degrees pf canppy distubance. Field was conducted in the Tapajos forest. Para Brazil. Seedling populations were monitored for two years in a 500 x 10 m belt transset. Ten of the eleven species had signifiantly clumped spatial distributions. The location of clumps was determined by the proximity of parant trees rather than canopy structure. Seedling mortality tended to reduce clumping. Large seedlings were proportionately more common in areas of low seedling density. Changes in population size large, and different species had differente temporal patterns of population change. It was concluded that lottery processes are likely to be important in maintaning species in tropical rain forest communities. In the same belt transect, the mortality and height growth of seedlings of six tree species were measured for two years. Mortality was greater at low crown exposure, and it was here that interspecific dfferences in mortality were most pronounced. Patterns of mortality did not reflect the known ecology of the species, and appenared to be the result of population. age/size structure. Height growth was low at low crown exposure, but increased with increasing crown exposure in five of the six species. Heoght growth did not result in changes in rank height order between species. The greatest interspecific differences in height growth occurred at the medium crown exposure classes. Events and processes ocurring under the closed canopy are hypothesised to be of grat importance in determining the composition and structure of seedling populations, and hence the community on which gap phase processes operate. An experiment was conducted to test the hypothesis that seedlings partition the forest microclimatic gradient. Seedlings of six tree species were transplanted into the forest, and a microclimatic gradient was artificially created manipulating the forest canopy. Canopy opening increased PPFD, temperature and decreased relative humidity, but hat comparatively litle effect on gravimentric soil water content. The microclimate was highly seasonal, with dry season PPFD and temperature higher and relative and soil water and lower than in the wet season. Microclimate also fluctuated on a number of different spatial and temporal scales. During the study period, analysis of the growth and mortality of the transplanted seedlings showed little evidence that species partitioned the microclimatic gradient. The tallest species at the time of gap creation remained tallest for 25 months all levels of irradiance, and irrespective of the season of gap creation. Changes in rank order were confined to the subordinate species.

Download or read book INSTANTANEOUS PHOTOSYNTHETIC RESPONSE TO TEMPERATURE OF MATURE FOREST CANOPIES AND EXPERIMENTALLY WARMED SEEDLINGS written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Tropical trees have been shown to be more susceptible to warming compared to temperate species, and have shown growth and photosynthetic declines at elevated temperatures as little as 3oC above ambient. However, regional and global vegetation models lack the data needed to accurately represent physiological response to increased temperatures in tropical forests. We compared the instantaneous photosynthetic responses to elevated temperatures of four mature tropical rainforest tree species in Puerto Rico and the temperate broadleaf species sugar maple (Acer saccharum) in Michigan. Contrary to expectations, leaves in the upper canopy of both temperate and tropical forests had temperature optima that are already exceeded by mean daily leaf temperatures. This indicates that tropical and temperate forests are already seeing photosynthesis decline at mid-day temperature. This decline may worsen as air temperatures rise with climate change if trees are unable to acclimate, increasing the likelihood that forests may shift from carbon sinks to sources. A secondary study was conducted on experimentally warmed sugar maple seedlings to determine if photosynthesis had been able to acclimate to +5oC air temperature over four years. Species abundance models had predicted a decline of sugar maple within the Upper Peninsula of Michigan over the next 100 years, due to elevated temperature and altered precipitation. Instantaneous photosynthetic temperature response curves on both control and heated seedlings showed that the differences between treatments were not statistically significant, though there was a 16% increase in temperature optima and a 3% increase in maximum rates of photosynthesis in warmed plots. Though evidence of acclimation was not significant, the seedlings did not fare poorly as the models suggest.

Download or read book Photosynthetic Characteristics of the Dominant Tree Species in Two Climatically Different Landscapes written by Mary K. Bresee and published by . This book was released on 2004 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Assessing leaf level processes in the context of other hierarchical levels (e.g., whole-plant, canopy, species, and landscape) is a current focus of ecophysiologists, and a discipline requiring additional research. The primary study objective was to examine foliar responses to light gradients (i.e., photosynthetically active radiation, PAR) across different species, age classes, and vertical positions in two landscapes: the northern deciduous forests of Wisconsin (CNF) and the Ozark highlands of southeastern Missouri (Ozarks). We measured the photosynthetic response of several light curve characteristics (e.g., maximum photosynthetic rate (Amax), stomatal conductance at Amax (gsmax), apparent quantum yield (f), and compensation point (G), and dark respiration rate (RD)) changes in microclimate (e.g., vapor pressure deficit (VPD), temperature, and fraction of PAR intercepted (fPAR)), leaf (e.g., SPAD chlorophyll concentration, (SCL)), and canopy characteristics (e.g., canopy openness) of ten tree species in two climatically different landscapes. Species include bigtooth aspen, paper birch, red oak, red maple and sugar maple (CNF) and shortleaf pine, hickory, scarlet, black, and white oaks (Ozarks). Three stand age classes (i.e., young, intermediate, and mature) were measured for all species in CNF. Stand age (CNF), species, and canopy position significantly affected a majority of the photosynthetic characteristics (a = 0.10). Furthermore, photosynthetic characteristics of shade intolerant species were typically greater than shade tolerant (p

Download or read book Comparative Photosynthetic Characteristics of Several Rainforest Tree Species in South east Queensland written by Perry W. Swanborough and published by . This book was released on 1992 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tropical Tree Physiology written by Guillermo Goldstein and published by Springer. This book was released on 2016-03-04 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest information on tropical tree physiology, making it a valuable research tool for a wide variety of researchers. It is also of general interest to ecologists (e.g. Ecological Society of America; > 3000 or 4000 members at annual meeting), physiologists (e.g. American Society of Plant Biologists; > 2,000 members at annual meeting), and tropical biologists (e.g. Association for Tropical Biology and Conservation, ATBC; > 500 members at annual meeting). (American Geophysical Union(AGU), > 20000 members at annual meeting). Since plant physiology is taught at every university that offers a life sciences, forestry or agricultural program, and physiology is a focus at research institutes and agencies worldwide, the book is a must-have for university and research institution libraries.

Download or read book Leaf Function in Tropical Rain Forest Canopy Trees written by Toon Rijkers and published by . This book was released on 2000 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Photosynthetic Characterisation of Tropical and Temperate Rainforest Species written by Nur Hazwani Binti Abdul Bahar and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rubisco catalyses a rate-limiting step in photosynthesis and is the largest nitrogen sink in leaves. The maximum rate of carboxylation of Rubisco, Vcmax, is routinely estimated from gas exchange using the Farquhar, von Caemmerer & Berry 1980 model of photosynthesis. As Vcmax allows mechanistic representation of photosynthesis, it has been incorporated into terrestrial biosphere models to estimate global primary productivity. However, doubts remain about previous estimates of Vcmax for globally important biomes, such as moist forests, both in tropical and temperate regions. In my thesis, I present a survey of Vcmax values - calculated assuming infinite mesophyll conductance - along a 3,300-meter elevation gradient from lowland western Amazon to the Andean tree line in Peru; this region is home to the largest moist forest on Earth. Large variations in Vcmax were found within and across the 18 field sites. As hypothesised, when estimated at a common measuring temperature (25°C), average Vcmax values of lowland Amazon trees were significantly lower than that of Andean trees. When data for the lowland Amazon and upland Andean trees were combined, the resultant mean tropical Vcmax value was lower than that of temperate trees reported in past studies. My analysis points to low Vcmax of Peruvian tropical trees being linked to limitations in phosphorus supply, and to a high proportion of Rubisco being inactive. The second part of my thesis investigated how mesophyll conductance influences the estimation of Vcmax for several Australian tropical (i.e. warm-adapted) and temperate (i.e. cool-adapted) moist-forest trees. Consistent with previous glasshouse studies, the selected tropical tree species exhibited significantly lower Vcmax values than their temperate counterparts. Importantly, I showed, for the first time, that the Vcmax estimated on the basis of intercellular CO2 partial pressure was equivalent to that on the basis of chloroplastic CO2 partial pressure, when using appropriate Michaelis-Menten constants for CO2 and O2. Thus, low mesophyll conductance in tropical moist forest is unlikely to account for the low estimates of Vcmax found in the Peruvian field work study. Finally, mechanisms underpinning development of photosynthesis in tropical moist forest trees, which include ontogenetic changes in leaf anatomy, and mesophyll and stomatal conductances, were examined. Key components of photosynthesis such as Vcmax, maximum electron transport rate and chlorophyll content increased synchronously during expansion, accompanied by development of leaf internal structures such as intercellular air spaces and mesophyll cells. The balance between photosynthetic carbon uptake and respiratory release changed dramatically during leaf development, reflecting a two-fold decline in area-based rates of respiration in expanding leaves as photosynthesis became fully functional. The dataset presented in my PhD thesis adds to the growing number of empirical estimates highly needed by the photosynthetic modelling communities, and validates the accuracy of Vcmax estimation using biochemical approaches. Collectively, my study is expected to contribute towards better understanding and representation of Vcmax in tropical forests.

Download or read book Growth of Tropical Rain Forest Trees as Dependent on Phosphorus Supply written by Dorinne Raaimakers and published by . This book was released on 1994 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plant Canopies written by Graham Russell and published by . This book was released on 1989 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is a synthesis of current knowledge about the growth, development and functioning of plant canopies. The term canopy is taken to include not only the upper surface of woodland, as in the original definition, but also analogous surfaces of other plant communities. Although much research has been carried out on single leaves, canopies are much more than just a collection of individual leaves, and so exhibit properties of their own. It can be argued that it is primarily at the canopy rather than the leaf level that solutions to many practical problems about the growth of plants in the field can be found. In this volume, canopy properties are considered in terms of the processes, such as transpiration and photosynthesis, by which the canopy and its environment interact. Topics discussed include the meaning of canopy structure, interception of solar radiation, exchange processes, nitrogen nutrition, leaf demography and heliotropism. Key principles are illustrated by examples from a wide range of plant community types and geographical locations. This book will be of interest to advanced students and research workers in agriculture, botany, crop sciences, ecology and forestry.

Download or read book Photosynthetic Induction Responses of Three Shade Tolerant Tree Species in the Neotropical Rainforest written by P. J. de Vries and published by . This book was released on 1998 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecophysiological Characteristics of Eight Rainforest Species Established in Mixed species Plantings written by Catherine Mary Drane and published by . This book was released on 1995 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Maintenance of Diversity in a Neotropical Seedling Community written by Corine Françoise Vriesendorp and published by . This book was released on 2002 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Nutrients on the Photosynthetic Capacity and Herbivory in Tropical Saplings written by Nele Smeyers and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Forests are the largest vegetative sink for atmospheric carbon (CO2). Anthropogenic emissions are compensated by carbon sequestration in trees, but nutrients could be limiting photosynthesis and the effect could be larger as believed. Tropical forests are often thought to be P limited as it is only available by weathering of the soil and decomposition. With the rising levels of carbon (C) and nitrogen (N) in the atmosphere an imbalance in CNP ratio is created. If P is limiting carbon uptake in tropical forests, global C cycle models are likely overestimating uptake by these ecosystems. Over the past decades, scientists have become increasingly concerned with quantifying correlations between key leaf traits and between leaf traits and climate. Wright et al. (2004) created the so called leaf economics spectrum, dividing all plant species in two specific groups, based on six key leaf traits, to which other leaf traits like herbivory could be related. The question whether this leaf economics spectrum exists within all terrestrial ecosystems remains. Our study was conducted on a site in the Amazonian rainforest in French Guiana. Spread over four species, 401 individuals were chosen divided over twelve plots from which total herbivory, leaf N content and leaf P content were measured. Photosynthetic capacity (Amax) and leaf area (LA) was measured of 138 of the previously mentioned individuals, but only in eight of the twelve plots. In this thesis we aimed to investigate relationships between both photosynthetic capacity and herbivory with leaf nutrient availability, and to link them to the leaf economics spectrum combined with P limitation. Our data confirmed the correlations of the leaf economics spectrum, apart for one deviating species. Positive correlations were found between herbivory, photosynthesis and leaf nutrient availability. Light availability was found to be a limiting factor of photosynthesis. We can conclude that more research should conducted on the leaf economics spectrum and the influence of anthropogenic emissions on this spectrum, with the consideration of the influence of P limitation on carbon uptake in tropical forests.

Download or read book Biomechanical Properties of Tropical Tree Seedlings as a Functional Correlate of Shade Tolerance written by Silvia Alvarez-Clare and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Physical disturbances by vertebrates and litterfall are important causes of seedling mortality in the understory of tropical forests. Thus, the capacity to resist or recover from mechanical damage should enhance seedling survival in shade. I explored interspecific variation in seedling biomechanical properties across a shade tolerance gradient, using eight tropical tree species from Barro Colorado Island (BCI), Panama. The stems and leaves of shade-tolerant species were constructed of stronger materials than were those of light-demanding species, as measured by a higher Young's modulus of elasticity, fracture toughness, and tissue density. These traits were highly correlated with tissue fiber content (especially % cellulose, but not % lignin) and with seedling survival during the first 6 mo.

Download or read book Brazilian Journal of Biology written by and published by . This book was released on 2008 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt: