Search

The first Global Assessment of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) found widespread, accelerating declines in Earth's biodiversity and associated benefits to people from nature. Addressing these trends will require science-based policy responses to reduce impacts, especially at national to local scales. Effective scaling of science-policy efforts, driven by global and national assessments, is a major challenge for turning assessment into action and will require unprecedented commitment by scientists to engage with communities of policy and practice. Fulfillment of science's social contract with society, and with nature, will require strong institutional support for scientists' participation in activities that transcend conventional research and publication.

The Millennium Ecosystem Assessment was modeled on the Intergovernmental Panel on Climate Change. It was carried out as a pilot of an assessment mechanism designed to meet decision makers’ needs for information on how human actions were changing biodiversity and ecosystems, how those changes were affecting ecosystem services and human well-being, and what actions could be taken to enhance environmental conservation and human well-being. Despite the considerable research that was available in 2000 on biodiversity and ecosystems and on various aspects of human well-being, it was surprisingly difficult to find research at the interface of natural and social sciences and economics. Yet the key questions being posed by decision-makers (e.g., ‘what will be the impact of biodiversity changes on local or national economies and human health’) required that interdisciplinary research. We encountered other key research gaps, including the need for better understanding of the cross-scale impacts of both environmental changes and policy interventions and the challenges of addressing questions of human well-being across different cultures and different understandings of science and epistemology. This paper identifies some of the most challenging elements of the assessment and the steps that were taken to address them. In addition to the knowledge assessed by the MA, one of the important outcomes was to stimulate greater interdisciplinary and transdisciplinary research to address these issues that were not only fundamentally scientifically interesting, but also critically important for decision makers.

Efforts to establish an ‘IPCC-like mechanism for biodiversity’, or an IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services), may culminate soon — as governments, the scientific community and other stakeholders are getting ready for a third round of negotiations on IPBES. This paper provides firstly, a brief history and broader context for the IPBES process; secondly, a description of the niche that IPBES would occupy in the science-policy landscape for biodiversity and ecosystem services; and thirdly, concludes with some views on the role of scientists in IPBES, and on the need to have strong and proper scientific structures to coordinate scientific efforts internationally, in order to produce the science needed for IPBES.

The Earth System Science Partnership (ESSP) was established in 2001 by four global environmental change (GEC) research programmes: DIVERSITAS, IGBP, IHDP and WCRP. ESSP facilitates the study of the Earth's environment as an integrated system in order to understand how and why it is changing, and to explore the implications of these changes for global and regional sustainability. Joint research projects on carbon dynamics, food, water and health have been established. As a result of an independent review, the ESSP developed a new strategy that will provide an internationally coordinated and holistic approach to Earth system science. The approach integrates natural and social sciences from regional to the global scale. The mainstay of the ESSP is to identify and define Earth system science challenges, enable integrative research to address these challenges, and build scientific capacity. The GEC research community also faces an increasing challenge to present research results in more accessible and informative ways to stakeholders, especially to policy-makers. In response, the ESSP is developing new services that include knowledge products, Earth system science fora, a synthesis journal and interdisciplinary collaborative research. Coping with GEC is an enormous challenge and one the world must respond to successfully. Our common goal is, therefore, to develop the essential knowledge base needed to respond effectively and quickly to the great challenge of GEC.

The capacity of ecosystems to deliver essential services to society is already under stress. The additional stresses imposed by climate change in the coming years will require extraordinary adaptation. We need to track the changing status of ecosystems, deepen our understanding of the biological underpinnings for ecosystem service delivery and develop new tools and techniques for maintaining and restoring resilient biological and social systems. We will be building on an ecosystem foundation that has been radically compromised during the past half century. Most rivers have been totally restructured, oceans have been severely altered and depleted, coral reefs are near the tipping point of disappearing as functional ecosystems, over half of the land surface is devoted to livestock and crop agriculture, with little consideration for the ecosystem services that are being lost as a consequence, some irrevocably so. We have already seen many regime shifts, or tipping points, due to human activity, even before the onset of measurable climate change impacts on ecosystems. Climate change, caused mainly by anthropogenic greenhouse gas emissions, will disrupt our ecosystem base in new ways. Already we are seeing widespread signs of change. Species behaviors are altering and disrupting mutualisms of long standing. We are seeing extinctions within vulnerable habitats and conditions where migrations are necessary for survival but where often there are no pathways available for successful movement in the fragmented world of today. These challenges represent an extraordinary threat to society and a call for urgent attention by the scientific community.

Terrestrial gastropods have been shown to exert major impacts on the plant structure and species composition of temperate grasslands and other terrestrial plant communities. In order to develop predictions of plant community responses to changing environments, it is critical to understand how factors structuring plant communities will be influenced by global changes. Nevertheless, little is known about the potential for the size and abundance of gastropods to be altered by the individual and combined effects of elevated atmospheric CO 2 and increased deposition of N. Previous work suggests that responses of herbivore abundance to these global changes seem likely to depend, in part, upon the changes in the quantity of plant biomass available for consumption, and changes in the nutritional quality of this plant material for gastropod survival, development, and reproduction. Therefore, in this study we investigated the effect of elevated CO 2 and increased N deposition on gastropod size and abundance, as well as the effects on plant community production and N status. Elevated CO 2 depressed the size of gastropods early in the growing season by 29% to 42%, increased mid-season gastropod abundance by 38% to 43%, and depressed abundance late in the growing season by 21% to 29%. These changes in gastropod size and abundance were due largely to the modification of plant tissue quality and quantity. Increased N deposition, in contrast, influenced neither gastropod abundance nor per capita biomass during any part of the growing season. Neither elevated CO 2 nor increased N deposition disrupted the temporal synchrony between plant production and slug abundance.

Hundreds of scientists from over 70 nations are now engaged in an intensive effort to assess what we know about the status of the world's ecosystems. Here, we describe the fundamental nature of this assessment, what it hopes to accomplish and how it will go about its work. The results of the Millennium Ecosystem Assessment will serve as a baseline for future assessments, as well as a blueprint for action for sustaining the ecosystem services upon which we all depend for our well being.

Eradications of invasive species often have striking positive effects on native biota. However, recent research has shown that species removal in isolation can also result in unexpected changes to other ecosystem components. These secondary effects will become more likely as numbers of interacting invaders increase in ecosystems, and as exotics in late stages of invasion eliminate native species and replace their functional roles. Food web and functional role frameworks can be used to identify ecological conditions that forecast the potential for unwanted secondary impacts. Integration of eradication into a holistic process of assessment and restoration will help safeguard against accidental, adverse effects on native ecosystems.

Soil organic carbon (SOC) is the largest reservoir of organic carbon in the terrestrial biosphere. Though the influence of increasing atmospheric CO2 on net primary productivity, on the flow of newly fixed carbon belowground, and on the quality of new plant litter in ecosystems has been examined, indirect effects of increased CO2 on breakdown of large SOC pools already in ecosystems are not well understood. We found that exposure of California grassland communities to elevated CO2 retarded decomposition of older SOC when mineral nutrients were abundant, thus increasing the turnover time of SOC already in the system. Under elevated CO2, soil microorganisms appeared to shift from consuming older SOC to utilizing easily degraded rhizodeposits derived from increased root biomass. In contrast to this increased retention of stabilized older SOC under elevated CO2, movement of newly fixed carbon from roots to stabilized SOC pools was retarded; though root biomass increased under elevated CO2, new carbon in mineral-bound pools decreased. These contrasting effects of elevated CO2 on dynamics of old and new soil carbon pools contribute to a new soil carbon equilibrium that could profoundly affect long-term net carbon movement between terrestrial ecosystems and the atmosphere.

In order to conduct modeling studies on the effects of elevated atmospheric carbon dioxide concentration ([CO 2 ]) on plant and ecosystem processes at the Jasper Ridge grassland in northern California, the generic plant simulator (GePSi) (Chen, J.-L. and Reynolds, J.F., 1997. Ecol. Model., 94: 53–66), is modified to simulate grass dynamics. This modification was attempted by the authors of this paper, who had no prior experience with the model. Prior to this project, GePSi, which is implemented in the object-oriented programming (OOP) language, C+ +, had only been used to model trees and woody shrubs. This exercise addressed several of the concepts presented in this volume concerning the purported benefits of genericness, modularity, and OOP in plant modeling. The objective of this paper is to briefly summarize the extent to which these benefits were realized and some of the problems encountered. Our evaluation is presented in terms of: (1) design considerations, including the importance of how the modules in GePSi were defined; and (2) the implementation phase, which critiques the use of OOP for facilitating the transfer of the model. This study suggests that generic, modular models such as GePSi will facilitate the interactions of model developers and users and reduce duplication of effort in model development.

A theoretical framework is presented to quantitatively describe the dynamics of biomass partitioning in plants. The approach is based on the assumption that nitrogen supply is limiting plant growth, and hence the nitrogen concentration of leaves is adjusted in such a way that the relative growth rate of the plant is maximized. Special emphasis is put on the incorporation of time-varying environmental conditions and on the inclusion of a stem compartment. Furthermore, the nitrogen concentrations may vary between leaves, stems and roots. Simulations show that the qualitative behaviour of the model is consistent with empirical and theoretical results.

The International Geophysical Year (IGY), which took place between July 1957 and December 1958, helped us to rethink the world. At a time when there was a major paradigm shift in our understanding of the physical world, the international collaboration of the IGY helped to reset the discipline. The International Biodiversity Observation Year (IBOY) is now occurring at a time when our dependence on, and understanding of, biodiversity is being acknowledged as a paradigm shift in our present view of the world. Although the benefits of IGY were initially intellectual with practical effects remaining unknown until many years later, the benefits of greater knowledge of biodiversity will support efforts towards sustainability and affect the quality of life, both now and in the future. By providing the framework for international collaborations between scientists involved in every aspect of life on Earth, IBOY has the potential to redefine our current understanding of biodiversity in a manner similar to how IGY helped redefine the geophysical world.

In virtually no area of the human enterprise is there more uncertainty than in matters of national defense. How well armed, trained, allied, clever, and persevering an aggressor might be is often uncertain. Moreover, the nature of an attack the direction of and with what weapons and strategy a strike might be made is normally deliberately concealed. In response to this great uncertainty, the United States has military bases around the world, nuclear submarines patrolling the remotest parts of the oceans, missiles poised to strike against any land or airborne target, and military satellites orbitin g the entire planet. Thousands of highly trained intelligence officers filter through the minutia of activities of perceived enemies and prepare elaborate contingency plans. The U.S. has carefully negotiated, verifiable international arms control treaties. Finally, it has developed the most advanced and sophisticated weapons and communications technology in the world to serve these functions. The cost of this form of military security currently consumes about a third of the United States’.federal budget. Indeed, the U.S. has spent in the last decade alone more than 1.5 trillion (1012> dollars to build up an arms apparatus against an enemy whose chance of attacking the U.S. in the last quarter century was never rated higher than about 3%. Now consider the stance of the current U.S. administration on global warming. Nearly every sector of the American economy could be adversely affected by climatic change, and nothing short of our national security and quality of life may be at stake. Most climatologists believe the chances of unprecedented climate change are at least 50%. Yet, offering as justification the uncertainty in timing and location of ‘the strike’, the Bush administration is doing virtually nothing to prepare a defense against this threat.

Anne Larigauderie is Executive Director of DIVERSITAS, the international programme dedicated to biodiversity science of ICSU and UNESCO. She has a PhD in plant ecophysiology (Montpellier, 1985) and spent over 10 years studying the impact of increasing atmospheric CO2 and temperature on natural vegetation in different ecosystems. In 1999, she joined the International Council for Science, ICSU, as Environment Science Officer, in charge of ICSU’s portfolio of environmental programmes. At DIVERSITAS, since 2002, she is interested in strengthening the science–policy interface for biodiversity, and the role of scientists at international policy fora where more science is needed.

Natural historians came late to California. By the time they arrived, there were but remnants left of the type of grasslands that had assembled and evolved under the influence of the prevailing Mediterranean-type climate. Deducing the character of the pristine grassland has been a very difficult task. However, it is clear that the original grassland was completely transformed in a very short period of time by aggressive introduced annual grasses from the Mediterranean Basin that became dominant throughout virtually the entire state.

This paper contributes to the Global Change and Terrestrial Ecosystems (GCTE) Carbon Initiative.

A growth chamber-based system was developed for controlling an array of shoot and root environmental factors for plant growth studies. A data acquisition and control system continuously monitors and regulates environmental conditions in each chamber as specified by a computer program. Shoot environmental factors which can be independently varied include air temperature, light intensity and photoperiod, relative humidity, and CO2 and SO2 gas concentrations. Root environment is controlled by regulating the temperature, pH and nitrate level of the hydroponic nutrient medium. Initial growth experiments have been conducted in which nitrate concentration in the hydroponic solution was held constant at levels from 5 mmol/m3 to 1000 mmol/m3, spanning a wide range of nitrogen limitation. Plants also have been raised either with or without SO2 (0–0.4 cm3/m3). Results of these studies show the degree of environmental control achieved, indicate the variation in plant growth response, and suggest the potential for experiments with combinations of controlled environmental stresses.

Summary The seasonal water relations of four plant species native to Death Valley were studied which were growing under both natural and irrigated conditions. These species included the winter annual, Camissonia claviformis , a summer-active herbaceous perennial, Tidestromia oblongifolia , and two evergreen perennials, Atriplex hymenelytra and, Larrea tridentata. Camissonia a plant with a high photosynthetic capacity had characteristics typical of most mesophytes under natural conditions and maintained high tissue water contents as well as high water and osmotic potential. Irrigation had little effect on these parameters for Camissonia. Tidestromia , which also has an unusually high photosynthetic capacity as well as a high rate of transpiration under natural conditions also has water balance characteristics not unlike many mesophytes although not to the same degree as Camissonia . The evergreen drought-enduring species which have a comparatively low photosynthetic capacity maintain low water and solute potentials at all seasons. Even at dawn when irrigated these species have low water potentials especially during the summer. In these xerophytes solute potential decreases during the course of the day. During the summer the plants under natural conditions have turgor pressures close to zero. The differential inherent photosynthetic capacities of these species are apparently strongly related to their inherent water balance characteristics.

Summary The thermal relations of the cactus Copiapoa haseltoniana were studied in the Atacama desert. These plants are oriented in such a manner as to minimize the absorption of midday solar radiation. Additional features, such as an epidermal surface that is highly wettable by fog and dew, and that is reflective when dry, apparently also operate to reduce the temperature differential between the plant and the air and hence increase water-use efficiency. In contrast, the meristematic and reproductive tissues are located so that they have high temperatures in relation to that of the air. This could be interpreted as a mechanism to increase growth and reproduction without affecting water-use efficiency.

Summary The annual carbohydrate economy of two trees in the mediterranean climate of California was studied. One, a drought-deciduous tree, Aesculus californica, stores large quantities of carbohydrate during the spring and early summer photosynthetic period which is subsequently used for massive fruit production in fall and for at least a portion of regrowth in February. In contrast, the evergreen oak, Quercus agrifolia, has little annual change in the carbohydrate status of its tissues and presumably channels photosynthate directly into fruits during this long development period. However, some reserves may be involved.

Monoterpene volatilization in Salvia mellifera is primarily dependent on the vapor pressures of the terpenes as they are influenced by temperature, the humidity of the air surrounding the leaf and the surface area of oil present on the leaf.