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Abstract Carbon use efficiency (CUE) represents how efficient a plant is at translating carbon gains through gross primary productivity (GPP) into net primary productivity (NPP) after respiratory costs (Ra). CUE varies across space with climate and species composition, but how CUE will respond to climate change is largely unknown due to uncertainty inRaat novel high temperatures. We use a plant physiological model validated against global CUE observations and LIDAR vegetation canopy height data and find that model‐predicted decreases in CUE are diagnostic of transitions from forests to shrubland at dry range edges. Under future climate scenarios, we show mean growing season CUE increases in core forested areas, but forest extent decreases at dry range edges, with substantial uncertainty in absolute CUE due to uncertainty inRa. Our results highlight that future forest resilience is nuanced and controlled by multiple competing mechanisms.
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Metropolitan Planning Organizations’ Uses of and Needs for Big Data
Big data products offer a new paradigm to understand and analyze human mobility patterns, a primary interest of long-range transportation planners. However, it remains unclear how widely these datasets are utilized by planners and to what extent they influence decision-making. We present the perspectives of more than 50 planners from MPOs across the United States. While we found a range of use cases, there was also a tendency to focus on a narrow set of applications.Transparency,regulation, andlegitimacyemerged as the primary factors influencing adoption decisions.
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- Award ID(s):
- 2114260
- PAR ID:
- 10615879
- Publisher / Repository:
- Transport Findings
- Date Published:
- Journal Name:
- Findings
- ISSN:
- 2652-8800
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract We infer the growth of large scale structure over the redshift range 0.4 ≲z≲ 1 from the cross-correlation of spectroscopically calibrated Luminous Red Galaxies (LRGs) selected from the Dark Energy Spectroscopic Instrument (DESI) legacy imaging survey with CMB lensing maps reconstructed from the latestPlanckand ACT data.We adopt a hybrid effective field theory (HEFT) model that robustly regulates the cosmological information obtainable from smaller scales, such that our cosmological constraints are reliably derived from the (predominantly) linear regime.We perform an extensive set of bandpower- and parameter-level systematics checks to ensure the robustness of our results and to characterize the uniformity of the LRG sample.We demonstrate that our results are stable to a wide range of modeling assumptions, finding excellent agreement with a linear theory analysis performed on a restricted range of scales.From a tomographic analysis of the four LRG photometric redshift bins we find that the rate of structure growth is consistent with ΛCDM with an overall amplitude that is ≃ 5-7% lower than predicted by primary CMB measurements with modest (∼ 2σ) statistical significance.From the combined analysis of all four bins and their cross-correlations withPlanckwe obtainS8= 0.765 ± 0.023, which is less discrepant with primary CMB measurements than previous DESI LRG crossPlanckCMB lensing results.From the cross-correlation with ACT we obtainS8= 0.790+0.024-0.027, while when jointly analyzingPlanckand ACT we findS8= 0.775+0.019-0.022from our data alone andσ8= 0.772+0.020-0.023with the addition of BAO data.These constraints are consistent with the latestPlanckprimary CMB analyses at the ≃ 1.6-2.2σlevel, and are in excellent agreement with galaxy lensing surveys.more » « less
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Abstract Replicability of divergence after contact is a poorly characterized process, particularly in the contexts of phylogeography and postglacial range dynamics within species. Using contact zones located at the leading‐, mid‐ and rear‐edges of a species' range, we examined variation in outcomes to contact between divergent lineages ofCampanula americana. We investigated whether contact zones vary in quantity and directionality of gene flow, how phylogeographic structure differs between contact zones, and how historic range dynamics may affect outcomes to contact. We found that all contact zones formed at similar times via primary contact yet detected significant admixture in only the rear‐edge (RE) contact zone. In the northern leading‐edge contact zone and the mid‐range Virginia contact zone, gene flow was minimal and asymmetric. In the southern RE contact zone, gene flow was strong and symmetric. Asymmetric admixture in the leading‐edge and Virginia contact zones matches the directionality of a known cosmopolitan cytonuclear incompatibility between lineages ofC. americana. Our results emphasize the dependence of speciation processes on phylogeographic structure, evolutionary history and range dynamics.more » « less
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Abstract PremiseA central goal of pollination biology is to connect plants with the identity of their pollinator(s). While predictions based on floral syndrome traits are extremely useful, direct observation can reveal further details of a species' pollination biology. The wildflowerPhlox drummondiihas a floral syndrome consistent with pollination by Lepidoptera. We tested this prediction using empirical data. MethodsWe observed each step of pollination inP. drummondii. First, we observed 55.5 h of floral visitation across the species range. We used temporal pollinator exclusion to determine the contribution of diurnal and nocturnal pollination to reproductive output. We then quantifiedP. drummondiipollen transfer by the dominant floral visitor,Battus philenor. Finally, we tested the effect ofB. philenorvisitation onP. drummondiireproduction by quantifying fruit set following single pollinator visits. ResultsBattus philenoris the primary pollinator ofP. drummondii. Pollination is largely diurnal, and we observed a variety of lepidopteran visitors during the diurnal period. However,B. philenorwas the most frequent visitor, representing 88.5% of all observed visits. Our results show thatB. philenoris an extremely common visitor and also an effective pollinator by demonstrating that individuals transfer pollen between flowers and that a single visit can elicit fruit set. ConclusionsOur data are consistent with the prediction of lepidopteran pollination and further reveal a single butterfly species,B. philenor, as the primary pollinator. Our study demonstrates the importance of empirical pollinator observations, adds to our understanding of pollination mechanics, and offers a specific case study of butterfly pollination.more » « less
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.32866/001c.127143
