Laureano A. Gherardi

University of California, Berkeley | UCB · Environmental Sciences Policy and Management

Variability of above-ground net primary production (ANPP) of arid to sub-humid ecosystems displays a closer association with precipitation when considered across space (based on multiyear averages for different locations) than through time (based on year-to-year change at single locations). Here, we propose a theory of controls of ANPP based on fou...

Significance Although increased climatic variability resulting from climate change has been accepted by the scientific community and forms part of the public narrative, studies of the effect of climatic variability on ecosystems have received much less attention than effects of changes in the mean state of climate. Here, we report on a field experi...

Climate‐change assessments project increasing precipitation variability through increased frequency of extreme events. However, the effects of inter‐annual precipitation variance per se on ecosystem functioning have been largely understudied. Here, we report on the effects of inter‐annual precipitation variability on the primary production of globa...

Significance Temporal and spatial variation in precipitation affect the functional composition of biological communities and ecosystems. Belowground, these changes disrupt the fragile balance between root herbivores, which are major constraints of ecosystem primary production, and their predators. We provide evidence that droughts and deluges alter...

Significance The fraction of fixed carbon allocated belowground in terrestrial ecosystems is the most uncertain component of global carbon cycle assessments. Here we present a novel approach to determining global quantification of belowground productivity, which is estimated at 24.7 Pg y ⁻¹ and accounts for 46% of terrestrial carbon fixation. Carbo...

Increases in the abundance of woody species have been reported to affect the provisioning of ecosystem services in drylands worldwide. However, it is virtually unknown how multiple biotic and abiotic drivers, such as climate, grazing, and fire, interact to determine woody dominance across global drylands. We conducted a standardized field survey in...

Climate change is increasing the frequency and severity of short-term (~1 y) drought events—the most common duration of drought—globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in t...

Climate change is projected to cause shifts in precipitation regimes globally, leading to intensified periods of precipitation and droughts. Most studies that have explored the influence of changing precipitation regimes on ecosystems have focused on changes in mean annual precipitation, rather than the variance around the mean. Soil fungi are ubiq...

Woody‐plant encroachment is a global phenomenon that has been affecting the southwestern United States since the late 1800s. Drought, overgrazing, herbivory, and competition between grasses and shrub seedlings have been hypothesized as the main drivers of shrub establishment. However, there is limited knowledge about the interactions among these dr...

Synchronous dynamics (fluctuations that occur in unison) are universal phenomena with widespread implications for ecological stability. Synchronous dynamics can amplify the destabilizing effect of environmental variability on ecosystem functions such as productivity, whereas the inverse, compensatory dynamics, can stabilize function. Here we combin...

Climate change is predicted to cause alterations in precipitation patterns in grasslands around the globe. The implications of these changes for soil biota and multiple key ecosystem functions that they regulate in grasslands is little known. We used soil nematodes as biological indicators in grassland ecosystems experiencing large shifts in precip...

Free-living nematodes are one of the most diverse metazoan taxa in terrestrial ecosystems and are critical to the global soil carbon (C) cycling through their role in organic matter decomposition. They are highly dependent on water availability for movement, feeding, and reproduction. Projected changes in precipitation across temporal and spatial s...

Understanding the processes that stabilize species populations is a fundamental question in ecology and central to conservation biology. In metapopulations, dispersal can act as a ‘double edged' sword for species stability by simultaneously decreasing local population variability (thereby decreasing local extinction risk) while increasing spatial s...

Mathematical techniques have a long and rich history in ecology, often serving as a virtual laboratory to test hypotheses, generate novel predictions, and investigate underlying ecological mechanisms. Recently, novel simulation techniques, advances in computing power, and numerical methods for implementing statistical models have significantly adva...

Synchrony is broadly important to population and community dynamics due to its ubiquity and implications for extinction dynamics, system stability, and species diversity. Investigations of synchrony in community ecology have tended to focus on covariance in the abundances of multiple species in a single location. Yet, the importance of regional env...

Significance Predicting the effects of anthropogenic nutrient enrichment on plant communities is critical for managing implications for biodiversity and ecosystem services. Plant functional types that fix atmospheric nitrogen (e.g., legumes) may be at particular risk of nutrient-driven global decline, yet global-scale evidence is lacking. Using an...

The fraction of primary productivity allocated below‐ground accounts for a larger flow of carbon than above‐ground productivity in most grassland ecosystems. Here, we addressed the question of how root herbivory affects below‐ground allocation of a dominant shortgrass prairie grass in response to water availability. We predicted that high levels of...

Plant parasitic nematodes are among the greatest consumers of primary production in terrestrial ecosystems. Their feeding strategies can be divided into endoparasites and ectoparasites that differ substantially, not only in their damage potential to host tissue and primary production, but also in their susceptibility to environmental changes. Clima...

Grasslands worldwide are expected to experience an increase in extreme events such as drought, along with simultaneous increases in mineral nutrient inputs as a result of human industrial activities. These changes are likely to interact because elevated nutrient inputs may alter plant diversity and increase the sensitivity to droughts. Dividing a s...

Grasslands are subject to considerable alteration due to human activities globally, including widespread changes in populations and composition of large mammalian herbivores and elevated supply of nutrients. Grassland soils remain important reservoirs of carbon (C) and nitrogen (N). Herbivores may affect both C and N pools and these changes likely...

Precipitation is a global driver of animal abundance and diversity in terrestrial ecosystems, but we know little on how it influences the body size structure of invertebrate communities, particularly soil fauna. It is unclear whether aridity limits the abundance of large-bodied soil invertebrates, and whether temporal precipitation changes can indu...

Ecosystem ecology, like all scientific disciplines, is often propelled forward by “classic” papers that identify key concepts within the field and define the core questions for generations of scientists. Here, we examine the legacy and sustained impact of a paper long considered a classic in ecology, E.P. (Gene) Odum’s 1969 “The strategy of ecosyst...

Soil stores approximately twice as much carbon as the atmosphere and fluctuations in the size of the soil carbon pool directly influence climate conditions. We used the Nutrient Network global change experiment to examine how anthropogenic nutrient enrichment might influence grassland soil carbon storage at a global scale. In isolation, enrichment...

Climatic changes are altering Earth's hydrological cycle, resulting in altered precipitation amounts, increased inter-annual variability of precipitation, and more frequent extreme precipitation events. These trends will likely continue into the future, having substantial impacts on net primary productivity (NPP) and associated ecosystem services s...

Although precipitation interannual variability is projected to increase due to climate change, effects of changes in precipitation variance have received considerable less attention than effects of changes in the mean state of climate. Interannual precipitation variability effects on functional diversity and its consequences for ecosystem functioni...

Advances in the acquisition and dissemination of knowledge over the last decade have dramatically reshaped the way that ecological research is conducted. The advent of large, technology-based resources such as iNaturalist, Genbank, or the Global Biodiversity Information Facility (GBIF) allow ecologists to work at spatio-temporal scales previously u...

We present a case for using Global Community Innovation Platforms (GCIPs), an approach to improve innovation and knowledge exchange in international scientific communities through a common and open online infrastructure. We highlight the value of GCIPs by focusing on recent efforts targeting the ecological sciences, where GCIPs are of high relevanc...

Climate change will result in increased precipitation variability with more extreme events reflected in more frequent droughts as well as more frequent extremely wet conditions. The increase in precipitation variability will occur at different temporal scales from intra to inter-annual and even longer scales. At the intra-annual scale, extreme prec...

We present a case for using global community innovation platforms (GCIPs), an approach to improve innovation and knowledge exchange in international scientific communities through a common and open online infrastructure. We highlight the value of GCIPs by focusing on recent efforts targeting the ecological sciences, where GCIPs are of high relevanc...

Background/Question/Methods In most arid and semiarid ecosystems the major impact of climate change will occur through changes in soil water availability. Current understanding of arid-ecosystem responses to changes in water availability is mostly based on observations or short-term manipulations. These methods are insufficient to estimate the ef...

Background/Question/Methods Climate change will result in increased frequency of extreme events that lead to higher precipitation variability at multiple temporal scales. Consequences of increasing precipitation variability on the functioning of ecosystems have received considerable less attention than assessments of the effects of changes in pre...

Understanding how biotic mechanisms confer stability in variable environments is a fundamental quest in ecology, and one that is becoming increasingly urgent with global change. Several mechanisms, notably a portfolio effect associated with species richness, compensatory dynamics generated by negative species covariance and selection for stable dom...

Background/Question/Methods Climate change will result not only in changes in mean precipitation but also in its variability. For example, the IPCC-A1B scenario predicts decreased precipitation by 5-10% and increased interannual variability for the Southwestern US. Consequences of increasing precipitation variability for the functioning of ecosyst...

Climate gradients shape spatial variation in the richness and composition of plant communities. Given future predicted changes in climate means and variability, and likely regional variation in the magnitudes of these changes, it is important to determine how temporal variation in climate influences temporal variation in plant community structure....

We have explored species-specific preferences for nitrate (NO3 (-)) and ammonium (NH4 (+)) as an alternative niche separation in ecosystems where nitrogen (N) is present mostly in inorganic forms. The Patagonian steppe is dominated by shrubs and grasses. Shrubs absorb water and nutrients from deep soil layers, which are poor in N, while grasses hav...

Water availability is the major limiting factor of the functioning of deserts and grasslands and is going to be severely modified by climate change. Field manipulative experiments of precipitation represent the best way to explore cause-effect relationships between water availability and ecosystem functioning. However, there is a limited number of...

Background/Question/Methods Climate change will result not only in changes in the mean climate state but also in the variability of climate. The IPCC-A1B scenario, predicts a decrease in precipitation of 5-10% for the Southwestern US and an increase in interannual variability. Consequences of increasing precipitation variability for the functioni...

Background/Question/Methods Climate change is rapidly altering weather patterns around the world, and most ecosystems are predicted to continue experiencing changing rainfall regimes in the future. Precipitation is a key mediator of mechanistic links between the below- and above-ground processes underlying ecosystem functions. Yet the joint respo...

Background/Question/Methods Climate variability is expected to increase with anthropogenic climate change. In grassland ecosystems, it is well known that annual net primary productivity (ANPP) is strongly controlled by annual precipitation. Patterns of species diversity can also be structured by interannual precipitation variability, with some sp...

Background/Question/Methods Climate change will result in an increase in the variability of precipitation within and among years as a result of different atmospheric phenomena. For many locations, there will be larger precipitation events interspersed with longer periods of droughts within a year, and more sequences of extreme dry years followed...

Background/Question/Methods Changing precipitation regimes, along with other global change factors, can alter the above- and below-ground processes that control carbon, water, and nutrient cycles in terrestrial ecosystems. The effects of climate change on the relationship between plants and microbes may be as important as climate impacts on eithe...

Background/Question/Methods Long-term manipulative experiments of water and nutrient availability are a unique tool for studying the functioning of arid and semiarid ecosystems. We might expect that ecological systems have hierarchical responses depending on the duration of resource availability. For example, aboveground net primary productivity...

Background/Question/Methods Nitrogen limits plant growth in almost all terrestrial ecosystems, even in arid and semiarid ecosystems. Vegetation in these ecosystems is usually made up of grasses and shrubs, which have different rooting patterns and strategies to acquire water and nutrients. Shallow-rooted grasses absorb N from a relatively N-rich...

Background/Question/Methods Warmer atmospheric temperatures will affect ecosystem functioning directly through changes in metabolic rate and tissue damage of organisms. Indirectly, increased temperatures can also affect ecosystem water balance with increased evapotranspiration (from bare-soil evaporation and transpiration) that reduces soil water a...

Background/Question/Methods In this study, we addressed how interannual rainfall determines belowground productivity through a multi-year manipulation experiment in the Jornada Experimental Range LTER site in the Northern Chihuahuan Desert in New Mexico. Through a factorial, ecosystem scale experiment containing drought (-80% and -50% below the a...

Background/Question/Methods Climate change is expected to impact precipitation regimes; for instance models specifically reveal reduced precipitation in North America. This study looks at the impacts of changes in precipitation quantity and nutrient levels on soil respiration in the Chihuahuan Desert in New Mexico. Specifically, soil respiration...

Background/Question/Methods Nitrogen limits plant growth in almost all terrestrial ecosystems. However, nitrogen fertilization experiments in water-limited ecosystems showed contradictory results. Our objective was to quantify plant growth response to N addition and to assess changes in this response along a precipitation gradient. The specific qu...