An official website of the United States government
Anthropogenic climate change is altering interactions among numerous species, including plants and pollinators. Plant-pollinator interactions, crucial for the persistence of most plant and many insect species, are threatened by climate change-driven phenological shifts. Phenological mismatches between plants and their pollinators may affect pollination services, and simulations indicated that these mismatches may reduce floral resources available to up to 50% of insect pollinator species. Although alpine plants rely heavily on vegetative reproduction, seedling recruitment and seed dispersal are likely to be important drivers of alpine community structure. Similarly, advanced flowering may expose plants to increased risk of frost damage and shifted soil moisture regimes; phenologically advanced plants will experience these environmental factors differently, which may alter their floral resource production. These effects may be dependent upon topography. Some species of alpine plants on the Niwot Ridge have displayed advanced phenology under treatments of advanced snowmelt (Forrester, 2021). However, little is understood about how these differences in distribution and phenology affect pollinator community composition and plant fecundity. Here we strive to examine how experimentally-induced changes in the timing of flowering and number of flowers produced by plants impact plant-pollinator interactions and seed set. We also ask how topography and the number of flowers interact with early snowmelt to affect pollination rates and the diversity of pollinating insects. Finally, we ask how seed set of Geum rossii is affected by pollinator visitation at different times of the season, under experimentally advanced snowmelt versus unmanipulated snowmelt, and with visitation by different insect taxa. In summer 2020, we found that plots with advanced phenology experienced peaks in pollinator visitation rates and pollinator diversity earlier than plots with unmanipulated snowmelt. We expect this to be because of the advanced floral phenology of certain key species in these plots. References: Forrester, C.C. (2021). Advancing, Using, and Teaching Climate Change Ecology Research. [Doctoral dissertation, University of Colorado, Boulder]. ProQuest Dissertations and Theses.
more »
« less
Colorado Native Pollinating Insects Health Study
Colorado is home to an incredibly rich community of native pollinating insects that contribute to the state’s economy and enhance Coloradans’ quality of life through the irreplaceable role they play in ecosystems. The pollination services these essential insects provide are at the heart of a healthy environment, contributing to our agricultural production and food systems, and relied upon by flowering plants across the state. In turn, flowering plants support the state’s wildlife, add color to the beautiful landscapes that we all treasure, and provide the basis for healthy functioning ecosystems. Despite their central importance, however, to date, no comprehensive assessment of the health of the state’s native pollinating insects has been conducted. Recognizing this need for coordinated state-level efforts to better understand the status and health of our native pollinating insects, Senate Bill 22-199, the Native Pollinating Insects Protection Study, was passed by the State Legislature and signed into law by Governor Jared Polis in May 2022. The Colorado Department of Natural Resources subsequently commissioned this study, awarded to a collaborative team of pollinator researchers, managers, and conservationists. The study was coordinated by Colorado State University Extension, in collaboration with the Xerces Society for Invertebrate Conservation and the University of Colorado Museum of Natural History, and in cooperation with leading experts in native pollinating insect ecology, management, and conservation.
more »
« less
- Award ID(s):
- 2016749
- PAR ID:
- 10645790
- Publisher / Repository:
- Denver: Colorado Department of Natural Resources
- Date Published:
- Page Range / eLocation ID:
- 1 - 305
- Subject(s) / Keyword(s):
- Pollinators Colorado health
- Format(s):
- Medium: X Other: PDF
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Given widespread concerns over human-mediated bee declines in abundance and species richness, conservation efforts are increasingly focused on maintaining natural habitats to support bee diversity in otherwise resource-poor environments. However, natural habitat patches can vary in composition, impacting landscape-level heterogeneity and affecting plant-pollinator interactions. Plant-pollinator networks, especially those based on pollen loads, can provide valuable insight into mutualistic relationships, such as revealing the degree of pollination specialization in a community; yet, local and landscape drivers of these network indices remain understudied within urbanizing landscapes. Beyond networks, analyzing pollen collection can reveal key information about species-level pollen preferences, providing plant restoration information for urban ecosystems. Through bee collection, vegetation surveys, and pollen load identification across ~350 km of urban habitat, we studied the impact of local and landscape-level management on plant-pollinator networks. We also quantified pollinator preferences for plants within urban grasslands. Bees exhibited higher foraging specialization with increasing habitat heterogeneity and visited fewer flowering species (decreased generality) with increasing semi-natural habitat cover. We also found strong pollinator species-specific flower foraging preferences, particularly for Asteraceae plants. We posit that maintaining native forbs and supporting landscape-level natural habitat cover and heterogeneity can provide pollinators with critical food resources across urbanizing ecosystems.more » « less
-
Background Landscape composition is known to affect both beneficial insect and pest communities on crop fields. Landscape composition therefore can impact ecosystem (dis)services provided by insects to crops. Though landscape effects on ecosystem service providers have been studied in large-scale agriculture in temperate regions, there is a lack of representation of tropical smallholder agriculture within this field of study, especially in sub-Sahara Africa. Legume crops can provide important food security and soil improvement benefits to vulnerable agriculturalists. However, legumes are dependent on pollinating insects, particularly bees (Hymenoptera: Apiformes) for production and are vulnerable to pests. We selected 10 pigeon pea (Fabaceae: Cajunus cajan (L.)) fields in Malawi with varying proportions of semi-natural habitat and agricultural area within a 1 km radius to study: (1) how the proportion of semi-natural habitat and agricultural area affects the abundance and richness of bees and abundance of florivorous blister beetles (Coleoptera: Melloidae ), (2) if the proportion of flowers damaged and fruit set difference between open and bagged flowers are correlated with the proportion of semi-natural habitat or agricultural area and (3) if pigeon pea fruit set difference between open and bagged flowers in these landscapes was constrained by pest damage or improved by bee visitation. Methods We performed three, ten-minute, 15 m, transects per field to assess blister beetle abundance and bee abundance and richness. Bees were captured and identified to (morpho)species. We assessed the proportion of flowers damaged by beetles during the flowering period. We performed a pollinator and pest exclusion experiment on 15 plants per field to assess whether fruit set was pollinator limited or constrained by pests. Results In our study, bee abundance was higher in areas with proportionally more agricultural area surrounding the fields. This effect was mostly driven by an increase in honeybees. Bee richness and beetle abundances were not affected by landscape characteristics, nor was flower damage or fruit set difference between bagged and open flowers. We did not observe a positive effect of bee density or richness, nor a negative effect of florivory, on fruit set difference. Discussion In our study area, pigeon pea flowers relatively late—well into the dry season. This could explain why we observe higher densities of bees in areas dominated by agriculture rather than in areas with more semi-natural habitat where resources for bees during this time of the year are scarce. Therefore, late flowering legumes may be an important food resource for bees during a period of scarcity in the seasonal tropics. The differences in patterns between our study and those conducted in temperate regions highlight the need for landscape-scale studies in areas outside the temperate region.more » « less
-
ABSTRACT Flowering plants can be visited by a wide diversity of pollinating insects; however, the structure of plant–insect interactions for non‐bee pollinators is not well‐known, even though non‐bee insects can play a central role in the pollination of many plant species. Pollination by non‐syrphid flies, such as bee flies (Bombylius majorL., Bombyliidae, Diptera), has often been underappreciated. Bee flies represent a diverse group of long‐tongue nectar‐feeding insects that are often reported as generalists who visit flowers indiscriminately. Here, we used individual‐based pollen transport networks to assess patterns of individual foraging in bee flies over two flowering seasons in a diverse co‐flowering community. Using this approach, we uncover the structure (e.g., modular vs. nested) of bee fly individual foraging and the degree of individual specialisation. We further evaluate the role of resource availability (floral abundance) and intraspecific trait variation (proboscis length and body size) in shaping individual specialisation. Overall, bee flies visited 20 different plant species. However, network analysis shows that individuals are more specialised and tend to partition the floral resource as reflected by the high degree of network modularity. Most bee fly individuals concentrate their foraging on only a few floral resources (two to four plant species) suggesting strong niche partitioning in this group of pollinators. This modular foraging pattern was not explained by differences in resource availability over the season. Proboscis length, however, was negatively related to the level of individual specialisation. Individuals with larger proboscis had larger foraging niches (less specialisation) perhaps due to easier access to a wide range of plant species with different floral tube sizes. Overall, our study reveals high individual specialisation and niche partitioning in bee‐fly interactions, mediated by differences in proboscis length, and with important implications for pollen transfer dynamics, plant–plant competition and plant reproductive success in diverse co‐flowering communities.more » « less
-
Wild bees are vital for the pollination of native plants and crops, providing essential ecosystem services. Climate change is known to impact biodiversity and species distributions, but insects adapted to desert ecosystems may exhibit unique physiological, behavioral, and evolutionary responses. The desert pallid bee (C. pallida), a solitary bee native to the arid southwestern United States and northern Mexico, primarily forages on yellow palo verde (P. microphylla), blue palo verde (P. florida), and desert ironwood (O. tesota). This study used MaxEnt to estimate the current and projected geographical overlap of suitable habitats for C. pallida and its host plants. Here, we used MaxEnt to estimate the current and forecasted overlapping geographically suitable habitat of C. pallida with all three host plants. We forecasted potential environmentally suitable areas for each species to the year 2040 using the current distribution model and climate projections with moderate CO2 levels. We found a continued spatial alignment in the suitable area of the bee and its host plants with a 70% increase in the range overlap area, though shifted to higher average altitudes and a slight northern expansion. These findings may provide insight to stakeholders on the conservation needs of desert-dwelling pollinators.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Service:
- The DOI is not currently available.
