David Inouye

University of Maryland, College Park | UMD, UMCP, University of Maryland College Park · Department of Biology

Recent reports of insect declines have caused concern among scientists and the public. Declines in insect abundance and biomass are ubiquitous across many climatic zones and have been largely attributed to anthropogenic land use intensification and climate change. However, there are few examples of long‐term continuous data in relatively undisturbe...

Climate change models often assume similar responses to temperatures across the range of a species, but local adaptation or phenotypic plasticity can lead plants and animals to respond differently to temperature in different parts of their range. To date, there have been few tests of this assumption at the scale of continents, so it is unclear if t...

Considerable uncertainty exists regarding the strength, direction and relative importance of the drivers of decomposition in the tundra biome, partly due to a lack of coordinated decomposition field studies in this remote environment. Here, we analysed 3717 incubations of two uniform litter types, green and rooibos tea, buried at 330 circum-Arctic...

Bumble bees are important pollinators for a great diversity of wild and cultivated plants, and in many parts of the world certain species have been found to be in decline, gone locally extinct, or even globally extinct. A large number of symbionts live on, in, or with these social bees. We give an overview of what is known about bumble bee ecto-sym...

Bumble bees (Bombus spp.) are important pollinators for both wild and agriculturally managed plants. We give an overview of what is known about the diverse community of internal potentially deleterious bumble bee symbionts, including viruses, bacteria, protozoans, fungi, and nematodes, as well as methods for their detection, quantification, and con...

The commercial production and subsequent movement of bumble bees for pollination of agricultural field and greenhouse crops is a growing industry in North America and globally. Concerns have been raised about the impacts of pathogen spillover from managed bees to wild pollinators, including from commercial bumble bees. We recommend development of a...

The timing of life events (phenology) can be influenced by climate. Studies from around the world tell us that climate cues and species' responses can vary greatly. If variation in climate effects on phenology is strong within a single ecosystem, climate change could lead to ecological disruption, but detailed data from diverse taxa within a single...

Phenological distributions are characterized by their central tendency, breadth, and shape, and all three determine the extent to which interacting species overlap in time. Pollination mutualisms rely on temporal co‐occurrence of pollinators and their floral resources, and although much work has been done to characterize the shapes of flower phenol...

Floral trait variation may help pollinators and nectar robbers identify their target plants and, thus, lead to differential selection pressure for defense capability against floral antagonists. However, the effect of floral trait variation among individuals within a population on multi-dimensional plant-animal interactions has been little explored....

Phenological distributions are characterized by their central tendency, breadth, and shape, and all three determine the extent to which interacting species overlap in time. Pollination mutualisms rely on temporal co-occurrence of pollinators and their floral resources, and while much work has been done to characterize the shapes of flower phenologi...

Life-history traits, which are physical traits or behaviours that affect growth, survivorship and reproduction, could play an important role in how well organisms respond to environmental change. By looking for trait-based responses within groups, we can gain a mechanistic understanding of why environmental change might favour or penalize certain s...

Snow is an important driver of ecosystem processes in cold biomes. Snow accumulation determines ground temperature, light conditions and moisture availability during winter. It also affects the growing season’s start and end, and plant access to moisture and nutrients. Here, we review the current knowledge of the snow cover’s role for vegetation, p...

Snow is an important driver of ecosystem processes in cold biomes. Snow accumulation determines ground temperature, light conditions, and moisture availability during winter. It also affects the growing season’s start and end, and plant access to moisture and nutrients. Here, we review the current knowledge of the snow cover’s role for vegetation,...

Climate change is a defining element of the current ecological landscape, with consequences ranging from global to local environments. One of the first indices of the ecological impact of the ongoing environmental changes was measurement of their effects on phenology, the seasonal timing of recurring annual events such as the beginning of the growi...

Cultivation of pollinator-dependent crops has expanded globally, increasing our reliance on insect pollination. This essential ecosystem service is provided by a wide range of managed and wild pollinators whose abundance and diversity are thought to be in decline, threatening sustainable food production. The Western honey bee (Apis mellifera) is am...

Understanding the effects of climate on the vital rates (e.g., survival, development, reproduction) and dynamics of natural populations is a long-standing quest in ecology, with ever-increasing relevance in the face of climate change. However, linking climate drivers to demographic processes requires identifying the appropriate time windows during...

North America has more than 4000 bee species, yet we have little information on the health, distribution, and population trends of most of these species. In the United States, what information is available is distributed across multiple institutions, and efforts to track bee populations are largely uncoordinated on a national scale. An overarching...

Bees are the most important pollinators in both managed and natural ecosystems, and yet concerns about bee declines are growing. Unfortunately, only a fraction of the 20,000 known bee species has adequate data to assess the status of species and susceptibility of populations to decline. The iDigBees Thematic Collections Network (TCN), comprised of...

Climate change is shifting the environmental cues that determine the phenology of interacting species. Plant–pollinator systems may be susceptible to temporal mismatch if bees and flowering plants differ in their phenological responses to warming temperatures. While the cues that trigger flowering are well‐understood, little is known about what det...

Founder of conservation biology

The timing of spring initiates an important period for resource availability for large trophic webs within ecosystems, including forage for grazing animals, flowers for pollinators, and the higher trophic levels that depend on these resources. Spring timing is highly variable across space, being influenced strongly by the departure of snow cover (i...

Many animals have the potential to discriminate nonspectral colors. For humans, purple is the clearest example of a nonspectral color. It is perceived when two color cone types in the retina (blue and red) with nonadjacent spectral sensitivity curves are predominantly stimulated. Purple is considered nonspectral because no monochromatic light (such...

Insects other than bees (i.e., non-bees) have been acknowledged as important crop pollinators, but our understanding of which crop plants they visit and how effective they are as crop pollinators is limited. To compare visitation and efficiency of crop-pollinating bees and non-bees at a global scale, we review the literature published from 1950 to...

Phenological responses to climate change are the most commonly measured responses of plants and animals to climate change, and most studies show that species are advancing the timing of their seasonal activities in response to warming temperatures. Birds interact with a wide range of other species, playing roles as herbivores, predators, prey, and...

The global increase in the proportion of land cultivated with pollinator‐dependent crops implies increased reliance on pollination services. Yet agricultural practices themselves can profoundly affect pollinator supply and pollination. Extensive monocultures are associated with a limited pollinator supply and reduced pollination, whereas agricultur...

Alpine environments are among the habitats most strongly affected by climate change, and consequently their unique plants and pollinators are faced with the challenge of adapting or going extinct. Changes in temperature and precipitation affect snowpack and snowmelt, resulting in changes in the growing season in this environment where plant growth...

Despite a global footprint of shifts in flowering phenology in response to climate change, the reproductive consequences of these shifts are poorly understood. Furthermore, it is unknown whether altered flowering times affect plant population viability. We examine whether climate change‐induced earlier flowering has consequences for population pers...

Changes from historic weather patterns have affected the phenology of many organisms world‐wide. Altered phenology can introduce organisms to novel abiotic conditions during growth and modify species interactions, both of which could drive changes in reproduction. We explored how climate change can alter plant reproduction using an experiment in wh...

In the version of this Article originally published, the rate of change plotted in Figure 2 was incorrect because of a coding error. The corrected figure is shown below. In the original Figure 2 legend, the onset of flowering slope was given as ‘0.99, 95% CI: 0.90–1.08’, the cessation of flowering slope was given as ‘1.02, 95% CI: 0.91–1.13’, and t...

The global trade of species promotes diverse human activities but also facilitates the introduction of potentially invasive species into new environments. As species ignore national boundaries, unilateral national decisions concerning species trade set the stage for transnational species invasion with significant conservation, economic and politica...

Climate change has induced pronounced shifts in the reproductive phenology of plants, yet we know little about which environmental factors contribute to interspecific variation in responses and their effects on fitness. We integrate data from a 43 yr record of first flowering for six species in subalpine Colorado meadows with a 3 yr snow manipulati...

1. In many flowering plants, bumble bees may forage as both pollinators and nectar robbers. This mixed foraging behaviour may be influenced by community context and consequently, potentially affect pollination of the focal plant. 2. Salvia przewalskii is both pollinated and robbed exclusively by bumble bees. In the present study area, it was legiti...

Climate change affects not just where species are found, but also when species' key life-history events occur-their phenology. Measuring such changes in timing is often hampered by a reliance on biased survey data: surveys identify that an event has taken place (for example, the flower is in bloom), but not when that event happened (for example, th...

Climate change can influence consumer populations both directly, by affecting survival and reproduction, and indirectly, by altering resources. However, little is known about the relative importance of direct and indirect effects, particularly for species important to ecosystem functioning, like pollinators. We used structural equation modelling to...

Climate change can influence the abundance of insect herbivores through direct and indirect mechanisms. In this study, we evaluated multitrophic drivers of herbivore abundance for an aphid species (Aphis helianthi) in a subalpine food web consisting of a host plant (Ligusticum porteri), mutualist ants and predatory lygus bugs (Lygus spp.). We used...

Climate change has induced pronounced shifts in the reproductive phenology of plants, with the timing of first flowering advancing in most species. Indeed, population persistence may be threatened by the inability to track climate change phenologically. Nevertheless, substantial variation exists in biological responses to climate change across taxa...

Frost is an important episodic event that damages plant tissues through the formation of ice crystals at or below freezing temperatures. In montane regions, where climate change is expected to cause earlier snowmelt but may not change the last frost-free day of the year, plants that bud earlier might be directly impacted by frost through damage to...

Studies have indicated that florivory and nectar robbing may reduce reproductive success of host plants. However, whether and how these effects might interact when plants are simultaneously attacked by both florivores and nectar robbers still needs further investigation. We used Iris bulleyana to detect the interactions among florivory, nectar robb...

Climate drivers of plant phenology in the subtropics and tropics are still unclear, which significantly hinders accurate prediction of climate change impacts on vegetation growth and carbon balance in these unique ecoregions. The basic hypothesis of process-based phenology models is that spring tree phenology is regulated by temperature and trigger...

Time series have played a critical role in documenting how phenology responds to climate change. However, regressing phenological responses against climatic predictors involves the risk of finding potentially spurious climate-phenology relationships simply because both variables also change across years. Detrending by year is a way to address this...

Background and aims: It has been suggested that the dynamics of nectar replenishment could differ for flowers after being nectar robbed or visited legitimately, but further experimental work is needed to investigate this hypothesis. This study aimed to assess the role of nectar replenishment in mediating the effects of nectar robbing on pollinator...

IN THEIR POLICY Forum “Ten policies for pollinators” (25 November, p. [975][1]), L. V. Dicks et al. suggest policies that governments should consider to protect pollinators and secure pollination services. Those suggestions were extracted from the 2016 Intergovernmental Science-Policy Platform

Time series have played a critical role in documenting how phenology responds to climate change. However, regressing phenological responses against climatic predictors involves the risk of finding potentially spurious climate-phenology relationships simply because both variables also change across years. Detrending by year is a way to address this...

The assumption of a linear relationship between temperature and phenophases may be misleading. Furthermore, a lack of understanding of the changes in temperature sensitivity of phenophases to changes in temperature strongly limits our ability to predict phenological change in response to climate change. We investigated the timing of seven phenophas...

Most of the world’s wild flowering plants (87.5%) are pollinated by insects and other animals (established but incomplete), more than three quarters of the leading types of global food crops can benefit, at least in part, from animal pollination (well established) and it is estimated that about one-third of global food volume produced similarly ben...

Understanding the influence of environmental variability on population dynamics is a fundamental goal of ecology. Theory suggests that, for populations in variable environments, temporal correlations between demographic vital rates (e.g., growth, survival, reproduction) can increase (if positive) or decrease (if negative) the variability of year-to...

Shifts in the timing of life history events have become an important source of information about how organisms are responding to climate change. Phenological data have generally been treated as purely temporal, with scant attention to the inherent spatial aspects of such data. However, phenological data are tied to a specific location, and consider...

Changing sex ratios Climate-warming temperatures might be expected to affect the sex ratio of species if sex determination is temperature-dependent. Petry et al. show that indirect climate effects could also alter sex ratios in species in which sex is genetically determined and damage reproductive fitness (see the Perspective by Etterson and Mazer)...

Surveys of bumble bees and the plants they visit, carried out in 1974 near the Rocky Mountain Biological Laboratory in Colorado, were repeated in 2007, thus permiting the testing of hypotheses arising from observed climate change over the intervening 33-yr period. As expected, given an increase in average air temperature with climate warming and a...

Climate change has had numerous ecological effects, including species range shifts and altered phenology. Altering flowering phenology often affects plant reproduction, but the mechanisms behind these changes are not well-understood. To investigate why altering flowering phenology affects plant reproduction, we manipulated flowering phenology of th...

The science of ecology is about relationships—among organisms and habitats, on all scales—and how they provide information that helps us better understand our world. In the past 100 years, the field has moved from observations to experiments to forecasting. Next week, the Ecological Society of America (ESA), the world's largest ecological society,...

Diptera are important flower visitors and pollinators for many plant species and in a variety of habitats. Although Diptera are not as well studied as other groups of pollinators, there is a growing literature that we review here about the ecology of their foraging behaviour and their effectiveness as pollinators. We consider (1) how their foraging...

We used three long-term data sets from the southwestern US to investigate the reliability of flowering communities from the perspective of pollinators in extreme environments. The data sets come from three desert sites in New Mexico, two subalpine sites in Colorado, and an elevation gradient in Arizona. We used two indices to explore different temp...

Rapid temperature increase and its impacts on alpine ecosystems in the Qinghai-Tibetan Plateau, the world's highest and largest plateau, are a matter of global concern. Satellite observations have revealed distinctly different trend changes and contradicting temperature responses of vegetation green-up dates, leading to broad debate about the Plate...

EHS is the first ecological journal to be launched jointly by ecological societies from different countries, with an aim to encourage multi-scale, integrative, and interdisciplinary ecological studies and international collaborations between scientists from industrialized and industrializing countries. Ecosystem Health and Sustainability will publi...

Bee pollinators provide a critical ecosystem service to wild and agricultural plants but are reported to be declining world‐wide due to anthropogenic change. Long‐term data on bee abundance and diversity are scarce, and the need for additional quantitative sampling using repeatable methods has been emphasized. Recently, monitoring programmes have b...

Phylogenetic relationships may underlie species-specific phenological sensitivities to abiotic variation and may help to predict these responses to climate change. Although shared evolutionary history may mediate both phenology and phenological sensitivity to abiotic variation, few studies have explicitly investigated whether this is the case. We e...

Adaptive traits are hypothesised to incur fitness trade-offs, and a classical example is metal-tolerant plants that exhibit reduced competitive ability when grown on low-metal substrates. In the present study, we examined whether metal-hyperaccumulating plants exhibit a similar trade-off, by assessing competition across a soil-metal gradient in the...

Diptera are important flower visitors and pollinators for many plant species and in a variety of habitats. Although Diptera are not as well studied as other groups of pollinators, there is a growing literature that we review here about the ecology of their foraging behaviour and their effectiveness as pollinators. We consider (1) how their foraging...

The Ecological Society of America (ESA) has responded to the growing commitment among ecologists to make their science relevant to society through a series of concerted efforts, including the Sustainable Biosphere Initiative (1991), scientific assessment of ecosystem management (1996), ESA’s vision for the future (2003), Rapid Response Teams that r...

Background/Question/Methods Spatio-temporal variation in demographic rates is still an area of considerable theoretical and empirical interest in population ecology. Variation in demographic rates affects fitness, and it therefore has implications for population dynamics and evolution. In general, demographic rate variation is expected to decreas...

Background/Question/Methods In the southwestern United States, climate change may decrease water availability and increase surface and air temperatures. Climatic variations, including soil moisture availability, could have adverse effects on nectar production and pollinator behavior. Nectar rewards provide energy for pollinators and facilitate po...

Background/Question/Methods Long-term studies can provide important insights into ecological processes and interactions that cannot be gained from shorter investigations. Important but infrequent events such as mast flowering or late spring frosts can have significant demographic consequences and can have cascading trophic consequences for intera...

Background/Question/Methods Phenology is a critical life history trait with consequences for organisms’ survival, reproduction, and interactions with other species. Climate change has been shown to alter the phenologies of plants and animals, in some cases causing phenological mismatches between interacting species. Although phenological mismatche...

Climate change is significantly influencing phenology. One potential effect is that historically interacting partners will respond to climate change at different rates, creating the potential for a phenological mismatch among previously synchronized interacting species, or even sexes of the same species. Focusing on plant demographics in a plant–po...

Significance Seasonal timing of biological events, phenology, is one of the strongest bioindicators of climate change. Our general understanding of phenological responses to climate change is based almost solely on the first day on which an event is observed, limiting our understanding of how ecological communities may be responding as a whole. Usi...