We may not be able to make you love reading, but archaeology of knowledge will lead you to love reading starting from now. Book is the window to open the new world. The world that you want is in the better stage and level. World will always guide you to even the prestige stage of the life. You know, this is some of how reading will give you the kindness. In this case, more books you read more knowledge you know, but it can mean also the bore is full.

The archaeology of knowledge

There is growing recognition that classifying terrestrial plant species on the basis of their function (into 'functional types') rather than their higher taxonomic identity, is a promising way forward for tackling important ecological questions at the scale of ecosystems, landscapes or biomes. These questions include those on vegetation responses to and vegetation effects on, environmental changes (e.g. changes in climate, atmospheric chemistry, land use or other disturbances). There is also growing consensus about a shortlist of plant traits that should underlie such functional plant classifications, because they have strong predictive power of important ecosystem responses to environmental change and/or they themselves have strong impacts on ecosystem processes. The most favoured traits are those that are also relatively easy and inexpensive to measure for large numbers of plant species. Large international research efforts, promoted by the IGBP–GCTE Programme, are underway to screen predominant plant species in various ecosystems and biomes worldwide for such traits. This paper provides an international methodological protocol aimed at standardising this research effort, based on consensus among a broad group of scientists in this field. It features a practical handbook with step-by-step recipes, with relatively brief information about the ecological context, for 28 functional traits recognised as critical for tackling large-scale ecological questions.

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A handbook of protocols for standardised and easy measurement of plant functional traits worldwide

An important aim of plant ecology is to identify leading dimensions of ecological variation among species and to understand the basis for them. Dimensions that can readily be measured would be especially useful, because they might offer a path towards improved worldwide synthesis across the thousands of field experiments and ecophysiological studies that use just a few species each. Four dimensions are reviewed here. The leaf mass per area-leaf lifespan (LMA-LL) dimension expresses slow turnover of plant parts (at high LMA and long LL), long nutrient residence times, and slow response to favorable growth conditions. The seed mass-seed output (SM-SO) dimension is an important predictor of dispersal to establishment opportunities (seed output) and of establishment success in the face of hazards (seed mass). The LMA-LL and SM-SO dimensions are each underpinned by a single, comprehensible tradeoff, and their consequences are fairly well understood. The leaf size-twig size (LS-TS) spectrum has obvious consequences for the texture of canopies, but the costs and benefits of large versus small leaf and twig size are poorly understood. The height dimension has universally been seen as ecologically important and included in ecological strategy schemes. Nevertheless, height includes several tradeoffs and adaptive elements, which ideally should be treated separately. Each of these four dimensions varies at the scales of climate zones and of site types within landscapes. This variation can be interpreted as adaptation to the physical environment. Each dimension also varies widely among coexisting species. Most likely this within-site variation arises because the ecological opportunities for each species depend strongly on which other species are present, in other words, because the set of species at a site is a stable mixture of strategies.

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Plant Ecological Strategies: Some Leading Dimensions of Variation Between Species

Publisher Summary The study of leaf anatomy and of the mechanisms of the opening and closing of stomatal guard cells leads one to suppose that the stomata constitute the main or even the sole regulating system in leaf transpiration. Meteorologists have developed a wide variety of formulae for estimating evaporation from vegetation that are based entirely on weather variables and take no account at all of the species composition or stomatal properties of the transpiring vegetation. These “potential evaporation” formulae are widely and, to a large degree, successfully used for estimating evaporation from vegetation that is not water-stressed. Transpiration depends on stomatal conductance, net radiation receipt and upon air saturation deficit, temperature, and wind speed. Saturation deficit and wind speed vary through leaf boundary layers, through canopies, and through the atmosphere above the canopies. The sensitivity of saturation deficit to changes in stomatal conductance depends on where the saturation deficit is measured. If all of the stomata on a single leaf change aperture in unison, there may be a substantial change in saturation deficit measured at the leaf surface but a negligible change in saturation deficit measured a centimetre or two away, outside the leaf boundary layer.

Stomatal Control of Transpiration: Scaling Up from Leaf to Region

Contents

 Summary

I Introduction
II Variability of N : P ratios in response to nutrient  supply
III Critical N : P ratios as indicators of nutrient  limitation
IV Interspecific variation in N : P ratios
V Vegetation properties in relation to N : P ratios
VI Implications of N : P ratios for human impacts  on ecosystems
VII Conclusions

 Acknowledgements


 References



Summary
Nitrogen (N) and phosphorus (P) availability limit plant growth in most terrestrial ecosystems. This review examines how variation in the relative availability of N and P, as reflected by N : P ratios of plant biomass, influences vegetation composition and functioning. Plastic responses of plants to N and P supply cause up to 50-fold variation in biomass N : P ratios, associated with differences in root allocation, nutrient uptake, biomass turnover and reproductive output. Optimal N : P ratios – those of plants whose growth is equally limited by N and P – depend on species, growth rate, plant age and plant parts. At vegetation level, N : P ratios 20 often (not always) correspond to N- and P-limited biomass production, as shown by short-term fertilization experiments; however long-term effects of fertilization or effects on individual species can be different. N : P ratios are on average higher in graminoids than in forbs, and in stress-tolerant species compared with ruderals; they correlate negatively with the maximal relative growth rates of species and with their N-indicator values. At vegetation level, N : P ratios often correlate negatively with biomass production; high N : P ratios promote graminoids and stress tolerators relative to other species, whereas relationships with species richness are not consistent. N : P ratios are influenced by global change, increased atmospheric N deposition, and conservation managment.

https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/j.1469-8137.2004.01192.x

N : P ratios in terrestrial plants: variation and functional significance

. A wooded meadow at Laelatu in western Estonia was found to be very rich in vascular plants. The maximum number of species found was 25 in a 10 cm x 10 cm plot, 42 in a 20 cm x 20 cm plot and 63 in a 1 m2 plot.

Species richness is related to the management history of the site. The highest richness was found in sites with the most regular long-term mowing. Species density was lower in the case of fertilization or temporary cessation of mowing.

The richest community had an LAI of 2.8 and an above-ground dry biomass of 175 g/m2. With increasing height of the herb layer the number of species decreases. Small disturbances cause a remarkable decrease in species density.

High species richness in an Estonian wooded meadow

Leaf weight per area and leaf size of 85 Estonian woody species in relation to shade tolerance and light availability

Theses on the semiotic study of life as presented here provide a collectively formulated set of statements on what biology needs to be focused on in order to describe life as a process based on semiosis, or signaction. An aim of the biosemiotic approach is to explain how life evolves through all varieties of forms of communication and signification (including cellular adaptive behavior, animal communication, and human intellect) and to provide tools for grounding sign theories. We introduce the concept of semiotic threshold zone and analyze the concepts of semiosis, function, umwelt, and the like as the basic concepts for theoretical biology.

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Theses on Biosemiotics: Prolegomena to a Theoretical Biology

Jakob von Uexküll: An introduction

Dans le cadre du numero de la revue «Semiotica» (120, 3/4, 1998) consacre a la lecture de l'ouvrage de J. Hoffmeyer intitule «Signs of meaning in the universe» (1996), l'A. se propose de definir et de commenter les notions de semiosis, environnement et semiosphere sur lesquelles repose l'entreprise biosemiotique de Hoffmeyer, operant un tournant cognitif dans le domaine de la biologie. Examinant les finalites et les methodes de la biosemiotique concernant le concept d'information, le dualisme esprit-corps, l'opposition sciences humaines/sciences naturelles et humanite/nature, l'A. montre que la discipline definie par Hoffmeyer inaugure un nouveau paradigme en biologie empirique comme en biologie theorique, dressant des ponts entre des systemes complexes

Kalevi Kull

Papers

High species richness in an Estonian wooded meadow

Leaf weight per area and leaf size of 85 Estonian woody species in relation to shade tolerance and light availability

Theses on Biosemiotics: Prolegomena to a Theoretical Biology

Jakob von Uexküll: An introduction

On semiosis, Umwelt, and semiosphere