Leaf trait plasticity reveals interactive effects of temporally disjunct grazing and warming on plant communities.

Changes in climate and grazing intensity influence plant-community compositions and their functional structure. Yet, little is known about their possible interactive effects when climate change mainly has consequences during the growing season and grazing occurs off growing season (dormant season grazing). We examined the contribution of trait plasticity to the immediate responses in the functional structure of plant community due to the interplay between these two temporally disjunct drivers.

Temperature and pH define the realised niche space of arbuscular mycorrhizal fungi.

The arbuscular mycorrhizal (AM) fungi are a globally distributed group of soil organisms that play critical roles in ecosystem function. However, the ecological niches of individual AM fungal taxa are poorly understood. We collected > 300 soil samples from natural ecosystems worldwide and modelled the realised niches of AM fungal virtual taxa (VT; approximately species-level phylogroups).

Challenging Global Waste Management - Bioremediation to Detoxify Asbestos.

As the 21st century uncovers ever-increasing volumes of asbestos and asbestos-contaminated waste, we need a new way to stop 'grandfather's problem' from becoming that of our future generations. The production of inexpensive, mechanically strong, heat resistant building materials containing asbestos has inevitably led to its use in many public and residential buildings globally. It is therefore not surprising that since the asbestos boom in the 1970s, some 30 years later, the true extent of this hidden danger was exposed.

Effects of increased temperature on plant communities depend on landscape location and precipitation.

Global climate change is affecting and will continue to affect ecosystems worldwide. Specifically, temperature and precipitation are both expected to shift globally, and their separate and interactive effects will likely affect ecosystems differentially depending on current temperature, precipitation regimes, and other biotic and environmental factors. It is not currently understood how the effects of increasing temperature on plant communities may depend on either precipitation or where communities lie on soil moisture gradients.

Framework for assessment and phytoremediation of asbestos-contaminated sites.

We examine the feasibility of phytoremediation as an alternative strategy to limit the exposure of asbestos in site with asbestos-containing materials. We collected soils from four locations from two sites-one with naturally occurring asbestos, and another, a superfund site, where asbestos-containing materials were disposed over decades-and performed ecotoxicology tests. We also performed two experiments with crop cultivar and two grasses from serpentine ecotype and cultivar to determined best choice for phytoremediation.

Differential elemental uptake in three pseudo-metallophyte C grasses in situ in the eastern USA.

Background And Aims: Elemental uptake in serpentine floras in eastern North America is largely unknown. The objective of this study was to determine major and trace element concentrations in soil and leaves of three native pseudo-metallophyte C grasses in situ at five sites with three very different soil types, including three serpentine sites, in eastern USA.

Methods: Pseudo-total and extractible concentrations of 15 elements were measured and correlated from the soils and leaves of three species at the five sites.

Siderophore-mediated iron removal from chrysotile: Implications for asbestos toxicity reduction and bioremediation.

Asbestos fibers are highly toxic (Group 1 carcinogen) due to their high aspect ratio, durability, and the presence of iron. In nature, plants, fungi, and microorganisms release exudates, which can alter the physical and chemical properties of soil minerals including asbestos minerals. We examined whether exudates from bacteria and fungi at environmentally relevant concentrations can alter chrysotile, the most widely used asbestos mineral, and lower its toxicity.

Arbuscular mycorrhizal colonization has little consequence for plant heavy metal uptake in contaminated field soils.

The factors affecting plant uptake of heavy metals from metalliferous soils are deeply important to the remediation of polluted areas. Arbuscular mycorrhizal fungi (AMF), soil-dwelling fungi that engage in an intimate exchange of nutrients with plant roots, are thought to be involved in plant metal uptake as well. Here, we used a novel field-based approach to investigate the effects of AMF on plant metal uptake from soils in Palmerton, Pennsylvania, USA contaminated with heavy metals from a nearby zinc smelter.

Soil and ecosystem respiration responses to grazing, watering and experimental warming chamber treatments across topographical gradients in northern Mongolia.

Globally, soil respiration is one of the largest fluxes of carbon to the atmosphere and is known to be sensitive to climate change, representing a potential positive feedback. We conducted a number of field experiments to study independent and combined impacts of topography, watering, grazing and climate manipulations on bare soil and vegetated soil (i.e.

Leaf-trait plasticity and species vulnerability to climate change in a Mongolian steppe.

Climate change is expected to modify plant assemblages in ways that will have major consequences for ecosystem functions. How climate change will affect community composition will depend on how individual species respond, which is likely related to interspecific differences in functional traits. The extraordinary plasticity of some plant traits is typically neglected in assessing how climate change will affect different species.

Climate change and grazing interact to alter flowering patterns in the Mongolian steppe.

Socio-economic changes threaten nomadic pastoralism across the world, changing traditional grazing patterns. Such land-use changes will co-occur with climate change, and while both are potentially important determinants of future ecosystem functioning, interactions between them remain poorly understood. We investigated the effects of grazing by large herbivores and climate manipulation using open-top chambers (OTCs) on flower number and flowering species richness in mountain steppe of northern Mongolia.

Diversity of ageing across the tree of life.

Evolution drives, and is driven by, demography. A genotype moulds its phenotype's age patterns of mortality and fertility in an environment; these two patterns in turn determine the genotype's fitness in that environment. Hence, to understand the evolution of ageing, age patterns of mortality and reproduction need to be compared for species across the tree of life.

The effects of defoliation on carbon allocation: can carbon limitation reduce growth in favour of storage?

There is no consensus about how stresses such as low water availability and temperature limit tree growth. Sink limitation to growth and survival is often inferred if a given stress does not cause non-structural carbohydrate (NSC) concentrations or levels to decline along with growth. However, trees may actively maintain or increase NSC levels under moderate carbon stress, making the pattern of reduced growth and increased NSCs compatible with carbon limitation.

Plant response to climate change varies with topography, interactions with neighbors, and ecotype.

Predicting the future of any given species represents an unprecedented challenge in light of the many environmental and biological factors that affect organismal performance and that also interact with drivers of global change. In a three-year experiment set in the Mongolian steppe, we examined the response of the common grass Festuca lenensis to manipulated temperature and water while controlling for topographic variation, plant-plant interactions, and ecotypic differentiation. Plant survival and growth responses to a warmer, drier climate varied within the landscape.

A demographic approach to study effects of climate change in desert plants.

Desert species respond strongly to infrequent, intense pulses of precipitation. Consequently, indigenous flora has developed a rich repertoire of life-history strategies to deal with fluctuations in resource availability. Examinations of how future climate change will affect the biota often forecast negative impacts, but these-usually correlative-approaches overlook precipitation variation because they are based on averages.

Biotic contexts alter metal sequestration and AMF effects on plant growth in soils polluted with heavy metals.

Investigating how arbuscular mycorrhizal fungi (AMF)-plant interactions vary with edaphic conditions provides an opportunity to test the context-dependency of interspecific interactions. The relationship between AMF and their host plants in the context of other soil microbes was studied along a gradient of heavy metal contamination originating at the site of zinc smelters that operated for a century. The site is currently under restoration.

Vulnerability of the northern Mongolian steppe to climate change: insights from flower production and phenology.

The semiarid, northern Mongolian steppe, which still supports pastoral nomads who have used the steppe for millennia, has experienced an average 1.7 degrees C temperature rise over the past 40 years. Continuing climate change is likely to affect flowering phenology and flower numbers with potentially important consequences for plant community composition, ecosystem services, and herder livelihoods.

Comparisons of AM fungal spore communities with the same hosts but different soil chemistries over local and geographic scales.

Arbuscular mycorrhizal (AM) fungi are ubiquitous and ecologically important microbes in grasslands. Both the host plant species and soil properties have been suggested as potentially important factors structuring AM fungal communities based on studies within local field sites. However, characterizations of the communities in relation to both host plant identity and soil properties in natural plant communities across both local and broader geographic scales are rare.

Introducing short roots in a desert perennial: anatomy and spatiotemporal foraging responses to increased precipitation.

• The desert flora possesses diverse root architectures that result in fast growth in response to precipitation. We introduce the short root, a previously undescribed second-order root in the aridland chamaephyte Cryptantha flava, and explore fine root production. • We describe the short root anatomy and associated fine roots, correlate standing fine root crop with soil moisture, and explore the architectural level - the short root, third-order lateral roots, or the whole root system - at which fine roots are induced by watering and the amount of water required.

Evidence for ecological matching of whole AM fungal communities to the local plant-soil environment.

The range of ecological roles exhibited by arbuscular mycorrhizal (AM) fungi depends on functional differences among naturally occurring local assemblages of AM species. While functional differences have been demonstrated among AM fungal species and among geographic isolates of the same species, almost nothing is known about functional differences among whole communities of naturally occurring AM fungi. In the greenhouse, we reciprocally transplanted whole AM fungal communities between plant-soil systems representing a serpentine grassland and a tallgrass prairie, using as hosts two grasses common to both systems.

A hydraulic explanation for size-specific plant shrinkage: developmental hydraulic sectoriality.

• While great attention has been paid to the mechanisms controlling plant growth, much less is known about why and how plants shrink. The modular design of plants may facilitate the independence of modules if the xylem vasculature is hydraulically sectored. We examined the hydraulic connectivity of modules comprising juveniles and adults of the aridland chamaephyte Cryptantha flava (Boraginaceae), motivated by the observation that rosette mortality is spatially aggregated in adults, but not in juveniles.

Plant-soil feedback: testing the generality with the same grasses in serpentine and prairie soils.

Plants can alter soil properties in ways that feed back to affect plant performance. The extent that plant-soil feedback affects co-occurring plant species differentially will determine its impact on plant community structure. Whether feedback operates consistently across similar plant communities is little studied.

Testing nickel tolerance of Sorghastrum nutans and its associated soil microbial community from serpentine and prairie soils.

Ecotypes of Sorghastrum nutans from a naturally metalliferous serpentine grassland and the tallgrass prairie were assessed for Ni tolerance and their utility in remediation of Ni-polluted soils. Plants were inoculated with serpentine arbuscular mycorrhizal (AM) root inoculum or whole soil microbial communities, originating from either prairie or serpentine, to test their effects on plant performance in the presence of Ni. Serpentine plants had marginally higher Ni tolerance as indicated by higher survival.

Evaluating plant-soil feedback together with competition in a serpentine grassland.

Plants can alter biotic and abiotic soil characteristics in ways that feedback to change the performance of that same plant species relative to co-occurring plants. Most evidence for this plant-soil feedback comes from greenhouse studies of potted plants, and consequently, little is known about the importance of feedback in relation to other biological processes known to structure plant communities, such as plant-plant competition. In a field experiment with three C4 grasses, negative feedback was expressed through reduced survival and shoot biomass when seedlings were planted within existing clumps of conspecifics compared with clumps of heterospecifics.