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Summary: Global ecology – the study of the interactions among the Earth's ecosystems, land, atmosphere and oceans – depends crucially on global observations: this paper focuses on space‐based observations of global terrestrial ecosystems. Early global ecology relied on an extrapolation of detailed site‐level observations, using models of increasing complexity. Modern global ecology has been enabled largely by vegetation indices (greenness) from operational space‐based imagery but current capabilities greatly expand scientific possibilities. New observations from spacecraft in orbit allowed an estimation of gross carbon fluxes, photosynthesis, biomass burning, evapotranspiration and biomass, to create virtual eddy covariance sites in the sky. Planned missions will reveal the dimensions of the diversity of life itself. These observations will improve our understanding of the global productivity and carbon storage, land use, carbon cycle−climate feedback, diversity−productivity relationships and enable improved climate forecasts. Advances in remote sensing challenge ecologists to relate information organised by biome and species to new data arrayed by pixels and develop theory to address previously unobserved scales. [ABSTRACT FROM AUTHOR]

Summary: Although primarily valued for their suitability for oceanographic applications and soil moisture estimation, microwave remote sensing observations are also sensitive to plant water content (Mw). Since Mw depends on both plant water status and biomass, these observations have the potential to be useful for a range of plant drought response studies. In this paper, we introduce the principles behind microwave remote sensing observations to illustrate how they are sensitive to plant water content and discuss the relationship between landscape‐scale Mw and common stand‐scale metrics, including plant‐scale relative water content, live fuel moisture content and leaf water potential. Lastly, we discuss how various sensor types can be leveraged for specific applications depending on the spatio‐temporal resolution needed. [ABSTRACT FROM AUTHOR]

This paper describes the ecology of a coastal alluvial plain at Chichiriviche in northern Venezuela. The area supports a great diversity of plant communities, ranging from mangroves on the seaward edge of the plain to non-halophytic, fresh-water communities on the landward side. Small differences on topography result in a mosaic of saline and less-saline environments . Rainfall is strongly seasonal, causing superficial flooding of the alluvial plain in the rainy season and the creation of a hypersaline substratum during the dry season. As a consequence, much of the plain is devoid on vegetation. Towards the landward side of the plain there are numerous small 'vegetation islands', fringed by halophilic succulent herbs, and made up of deciduous and semi-deciduous shrubs and trees together with non-halophytic CAM plants such as cacti and bromeliads. In subsequent papers the results of ecophysiological studies of these diverse plant species are presented. [ABSTRACT FROM AUTHOR]

615I.615II.616III.618IV.622V.625VI.627VII.628628References628 Summary: Invasion science is a very active subdiscipline of ecology. However, some scientists contend that theoretical integration has been limited and that predictive power remains weak. This paper, focusing on plants, proposes a new multi‐pronged research strategy that builds on recent advances in invasion science. More intensive studies on particular model organisms and ecosystems are needed to improve our understanding of the full suite of interacting factors that influence invasions (‘model system research’). At the same time, comparative studies across many study systems are essential for unravelling the context‐dependencies of insights that emerge from particular studies (‘multi‐site studies’); and quantitative synthesis based on large datasets should be constrained to well‐defined theoretical domains (‘focused meta‐analysis’). We also suggest ways for better integration of information about species biology and ecosystem characteristics (‘invasion syndromes’). We expect that a resulting theory of invasions will need to be conceived as a somewhat heterogeneous conglomerate of elements of varying generality and predictive power: laws that apply to well‐specified domains, general concepts and theoretical frameworks that can guide thinking in research and management, and in‐depth knowledge about the drivers of particular invasions. [ABSTRACT FROM AUTHOR]

• Anthropogenic nitrogen (N) addition may substantially alter the terrestrial N cycle. However, a comprehensive understanding of how the ecosystem N cycle responds to external N input remains elusive. • Here, we evaluated the central tendencies of the responses of 15 variables associated with the ecosystem N cycle to N addition, using data extracted from 206 peer-reviewed papers. • Our results showed that the largest changes in the ecosystem N cycle caused by N addition were increases in soil inorganic N leaching (461%), soil NO3- concentration (429%), nitrification (154%), nitrous oxide emission (134%), and denitrification (84%). N addition also substantially increased soil NH4+ concentration (47%), and the N content in belowground (53%) and aboveground (44%) plant pools, leaves (24%), litter (24%) and dissolved organic N (21%). Total N content in the organic horizon (6.1%) and mineral soil (6.2%) slightly increased in response to N addition. However, N addition induced a decrease in microbial biomass N by 5.8%. • The increases in N effluxes caused by N addition were much greater than those in plant and soil pools except soil NO3-, suggesting a leaky terrestrial N system. [ABSTRACT FROM AUTHOR]

• This paper presents an architectural model of wheat (Triticum aestivum), designed to explain effects of light conditions at the individual leaf level on tillering kinetics. Various model variables, including blade length and curvature, were parameterized for spring wheat, and compared with winter wheat and other Gramineae species.• The architectural model enables simulation of plant properties at the level of individual organs. Parameterization was based on data derived from an outdoor experiment with spring wheat cv. Minaret.• Final organ dimensions of tillers could be modelled using the concept of relative phytomer numbers. Various variables in spring wheat showed marked similarities to winter wheat and other species, suggesting possibilities for a general Gramineae architectural model.• Our descriptive model is suitable for our objective: investigating light effects on tiller behaviour. However, we plan to replace the descriptive modelling solutions by physiological, mechanistic solutions, starting with the localized production and partitioning of assimilates as affected by abiotic growth factors.New Phytologist(2005)doi: 10.1111/j.1469-8137.2005.01337.x© New Phytologist(2005) [ABSTRACT FROM AUTHOR]

Comments on the initial success in the retrospective interpretation of the hydrosystem of trees as shown in the paper "Suitability of Chestnut Earlywood Vessel Chronologies for Ecological Studies," by P. Fonti and I. Garcia Gonzales. Features of dendroecology and dendroclimatology that need to be examined; Utility of the hydrosystem; Factors which can contribute to reconstruction of the climate in Central Europe.

Ecological transitions are at the core of different modes of speciation. These transitions face both genetic and demographic hurdles. This paper focuses on how these hurdles are overcome, allowing ecological speciation and speciation via hybridization and/or polyploidy. Niche shifting is a two-step process. First there is the establishment of ill-adapted populations where ecological opportunity allows. This is followed by the genetic refinement of populations, which allows them to be integrated into novel communities and habitats. These steps are more readily accomplished in unsaturated floras, where competition is less intense. Ecological transitions in saturated floras may be facilitated by disturbance. Invasive species serve as heuristic model systems for understanding the early stages of speciation where niche shifts are involved. [ABSTRACT FROM AUTHOR]

Numerous authors have attempted to quantity the physical properties of leaves in relation to aspects of leaf ecology, including decomposition, sclerophylly, herbivory, and leaf function and longevity. This paper examines the relative merits of the punch-and-die, tearing and shearing tests for assessing leaf physical properties. We conducted a series of these three mechanical tests on leaves of Solanum laciniatum, and determined the effect of various test parameters on the measurement of fracture properties. For the punch-and-die test, the parameters considered were machine speed, clearance between the punch and the die, edge definition of the punch, and area of the punch. Aspects of the tearing test examined were notch length, and effects, and length-to width requirements of t est strips, and for shearing tests the effects of blade proximity, angle and sharpness were investigated. All the test parameters investigated were found significantly to affect the assessment of leaf-fracture properties. In addition, fracture properties were found to vary significantly within leaves. Some general principles for designing and implementing tests are outlined. This study suggests that while punching and shearing tests are useful means of quantifying leaf fracture properties, the value of the tearing test may be reduced as it is most constrained by the biological nature of the test material. [ABSTRACT FROM AUTHOR]

Dark septate root endophytes (DSE) are conidial or sterile fungi (Deuteromycotina, Fungi Imperfecti) likely to be ascomycetous and colonizing plant roots. They have been reported for nearly 600 plant species representing about 320 genera and 100 families. DSE fungi occur from the tropics to arctic and alpine habitats and comprise a heterogeneous group that functionally and ecologically overlaps with soil fungi, saprotrophic rhizoplane-inhabiting fungi, obligately and facultatively pathogenic fungi and mycorrhizal fungi. Numerous species of undescribed sterile and anamorphic taxa may also await discovery. Although DSE are abundant in washed root and soil samples from various habitats, and are easily isolated from surface-sterilized roots of ecto-, ectendo-, endo- and non-mycorrhizal host species, their ecological functions are little understood. Studies of DSE thus fat have yielded inconsistent results and only poorly illustrate the role of DSE in their natural habitats. These inconsistencies are largely due to the uncertain taxonomic affinities of the strains of DSE used. In addition, because different strains of a single anamorph taxon seem to vary greatly in function, no clear generalizations on their ecological role have been drawn. This paper reviews the current literature on DSE and the ecology and discusses the need for and direction of future research. [ABSTRACT FROM AUTHOR]

This paper highlights major developments in the field of heavy metal tolerance in plants over the last 15 years. Advances in experimental and theoretical aspects are considered. The value of both intra- and interspecific studies in assessing the ecological significance of adaptive strategies is stressed. [ABSTRACT FROM AUTHOR]

At any point in time, any discipline in science tends to be seized by a particular methodology or enthusiasm and other approaches get 'dumped'. So it is in ecology -- although, because of obstinate individualism, nothing is ever completely forgotten. We are currently in a reductionist, population-dominated era. Twenty-five years ago, our interests lay primarily in comparisons of species. In between, the holistic approach has had a good run with studies of ecosystems everywhere. This introductory paper reflects on this history and particularly, because of the occasion, examines the value of the process of comparison. [ABSTRACT FROM AUTHOR]

The long period covered by this paper probably saw the most drastic changes wrought by man on the plant cover of these islands in the whole of postglacial history. Much of our information about vegetation changes comes from those parts of the country where peats and mires are abundant, which leaves those areas which were the cradle of successive cultural groups largely unrepresented. Sources of environmental evidence are now emerging even from this unpromising background, an important element amongst which are man's own works. The evidence of changes wrought by man may come from non-botanical as well as botanical material. Pollen, charcoal, phytoliths, seeds, mosses, and other macroscopic plant remains may be extracted, but indirect evidence may also be obtained from land snails, insects, bones (including small vertebrates), as well as from preserved soils and land surfaces. In the various environments considered a trend from forest through clearance to pastoral or arable agriculture can usually be demonstrated. These changes may ultimately result in site deterioration on a large scale, the nature of which will depend upon the ecological conditions and the practices at work. In extreme cases peat may form or soil erosion take place. On base-poor soils, soil acidification may become so intense that the land is no longer usable for traditional agriculture and is allowed to degenerate to moorland or heath. In early historic times much degraded land came into use again for hill-grazing, a process which further depauperated both the flora and the soils. [ABSTRACT FROM AUTHOR]

In some pollen analytical studies, the required information can be obtained without a complete analysis of the core. The paper describes with a practical example, strategies for economically extracting the required information, and indicate some properties of these strategies. [ABSTRACT FROM AUTHOR]

Ozone concentrations in many parts of Europe exceed the proposed UN-ECE Critical Levels for the protection of ecosystems but there is so little known about the effects on native, herbaceous species, that it is presently impossible to judge what effect, if any, these concentrations are having on this group of plants. This paper reports the results of an initial screening of 32 taxa that was used to select a small number of species for further work. All were exposed to 70 nI I-1 O2 given for 7 h d-1 for two weeks and the response measured in terms of mean relative growth rate (&Rbar;), the allometric root/shoot coefficient (K), arid changes in induced chlorophyll fluorescence (FR). Only six species showed visible symptoms but 14 showed a significant reduction &Rbar;. There was no relationship between the extent of visible symptoms and growth reduction, confirming that visible symptoms are often of little value in determining growth sensitivity to O3 stress. There were marked differences within genera and within species; a population of Plantago major collected in Athens showed no effects, while a Derbyshire population, with a 24% , reduction in R, was the most sensitive of taxa tested, including Bel-W3 tobacco which has been specifically bred for O3 sensitivity. There was a significant regression of &Rbar;% change on the &Rbar; of controls (&Rbar;% = 12.4- 10.4 × R, P = 0.0007, r = -0.56), implying that > 30%. of the variation in response between taxa was related to the inherent &Rbar;; faster growing taxa tending to show a greater reduction in &Rbar; on exposure to O3. It is tentatively suggested that this may be related to differences in stomatal conductance. [ABSTRACT FROM AUTHOR]

This paper is concerned with the value of the ecological information provided by response functions. Two questions are considered. The first deals with the spatial reproducibility of response functions depending on the tree population and the location of the meteorological station that yielded the climatic data. The second concerns the temporal stability of the response function. The climate ring- width relationships are calculated for six populations of Pinus silvestris (L.). Twelve meteorological stations are involved in this calculation, over the period 1890-1980, divided in five sequences of 50 years . Analogies and differences between response functions are investigated using multi-dimensional analysis (principal component analysis and cluster analysis). Spatial analysis reveals that the climate ring-width relationship mainly depends on the population habit. The temporal analysis shows that instability is linked with the evolution of the habitat, more especially with the expansion of the forest cover. [ABSTRACT FROM AUTHOR]

The article comments on the prominence of papers featured in the "New Phytologist" journal that consider various aspects of plant interactions with the environment. The author believes that the relative change in scope can be traced back over more than a century that the journal has been published. The coordinated efforts of scientists are needed to respond to the challenges posed by atmospheric and climactic change.

This article presents an introduction of the special issue of the journal "New Phytologist." This Special issue of the journal explore the impacts of variation in leaf structure on processes occurring from the level of the leaf itself to that ecosystem and biomes. The introductory review by Vince Gutschick assesses the basic consequences of differences in leaf structure, and this is followed by both reviews and research papers that expand on this theme: providing up-to-date accounts of the environmental, genotypic and whole-plant controls over leaf structure.