News

New NSF grant: Continent-wide forest recruitment change

New NSF grant: Continent-wide forest recruitment change

A new collaboration to understand forest regeneration and climate change will be led by Jim Clark, in collaboration with University of California Merced, University of California Berkeley, University of Michigan, and the North Carolina Museum of Natural History. The award will involve sampling seed production and wildlife populations across the continental US.

The sustainability of North American forests depends on seed production by trees and the seedlings that must establish the next generation. For most of North America, neither the amounts of seed that are produced, nor how much of that seed survives to become future forests is known. Planning for climate change requires this knowledge to anticipate tree species migrations and its impacts on the birds and mammals that depend on forests for habitat and food. This study combines continental scale tree fecundity estimates with a new generation of monitoring and synthesis methods for integrating tree fecundity, seedling success, and its impacts on animal consumers. The study will quantify current trends across the continent, the changes in forests that are happening now, and the habitat changes that are causing them. [more]

Stages critical to the conservation of forest communities with climate and habitat change, including tree fecundity (F), seed consumers (C), seed dispersers (D), and seedling browsers (B)
Maggie contributes to alpine dynamics study

Maggie contributes to alpine dynamics study

Predictive steady-state abundance distributions for each species group across observed gradients of ambient (left) and augmented (right) N deposition (zero centred ± two standard deviations) in global change plots, respectively (see Figure S9 for all treatments). Points show simulated equilibrium abundances (100 at each value of ×).
Predictive steady-state abundance for each species group across observed gradients of ambient (left) and augmented (right) N deposition (zero centred ± two standard deviations) in global change plots. Points show simulated equilibrium abundances (100 at each value of ×).

Maggie collaborated using gjamTime to understand dynamic species interactions in response to climate change. Density-dependent shifts in competitive interactions drove long-term changes in abundance of species-groups under global change while counteracting environmental drivers limited the growth response of the dominant species through density-independent mechanisms. Furthermore, competitive interactions shifted with the environment, primarily with nitrogen and drove non-linear abundance responses across environmental gradients [more]

 

Collins, C.G., Elmendorf, S.C., Smith, J.G., Shoemaker, L., Szojka, M., Swift, M., and K. N. Suding. 2022. Global change re-structures alpine plant communities through interacting abiotic and biotic effects Ecology Letters, 25, 1813-1826. https://doi.org/10.1111/ele.14060

Dr Becky Tang, Middlebury next

Dr Becky Tang, Middlebury next

Becky defended her PhD in the Department of Statistical Science, advised by Alan Gelfand and Jim Clark. She next heads to a tenure track faculty position at Middlebury College.

Becky was recognized by the American Statistical Association for her paper, “Modeling spatially biased citizen science effort through the eBird database” in Environmental and Ecological Statistics. This paper also received the Best Award from the Department of Statistical Science.

Tang, B., J. S. Clark, and A. E. Gelfand. 2021. Modeling spatially biased citizen science effort through the eBird database. Environmental and Ecological Statistics, https://doi.org/10.1007/s10651-021-00508-1.

Fishing gear leading cause of North Atlantic right whale decline

Fishing gear leading cause of North Atlantic right whale decline

New research finds that North Atlantic right whales with severe injuries are more likely to die than those with minor ones, making entanglements the leading cause of serious injury and mortality in the critically endangered species. The research underscores the urgent need for changes to the fishing industry as the species, with an estimated population of less than 350 individuals, faces extinction. The study, published in Conservation Science and Practice, also found that sub-lethal effects on reproductive success are more pronounced than previously recognized. Read more…

(Left) Female right whale “Bayla” last seen in good health with no fishing gear on Feb. 23, 2010. (Middle) Sighted with attached gear and severe injuries on Dec. 25, 2010, and (right) found dead Feb. 1, 2011 after an unsuccessful disentanglement effort. She was 2 years old. CREDIT: Florida Fish and Wildlife Conservation Commission, taken under NOAA research permits #594-1759 and #932-1905/MA009526
New interns for 2022

New interns for 2022


This summer, there are five people working with Renata’s urban tree-health study, two in Chicago and three in Durham. The three Durham technicians are Chloe Schueller, Maggio Laquidara, and Lucie Ciccone. They will each examine different aspects tree health across the city of Durham and the Duke campus. Topics include impacts of maintenance on tree health, urban bird habitats, and the social and political factors that influence tree health in cities. Renata’s site includes bios.

Valentin Journe awarded Polonez Biz Fellowship

Valentin Journe awarded Polonez Biz Fellowship

POLONEZ BIS is co-funded by the European Commission and the Polish National Science Centre under the Marie Skłodowska-Curie COFUND grant. In three calls to be announced in 2021 and 2022 the programme will recruit 120 experienced researchers from all over the world. They will move to Poland for 24 months to conduct their basic research in public or private institutions of their choice. Valentin will be collaborating with Michal Bodgziewicz and Jim Clark on masting dynamics.

Valentin Journe, postdoc
Oldest bald cypress

Oldest bald cypress

Some of us trekked down the Black River to trees aged by Dave Stahle at > 2600 yr. Led by Don of Mahanaim Adventures, we entered the ancient stand from upstream. Continuing drought in the Southeast left us to portage the swamp interior. Many large trees have snapped in this hurricane-battered watershed, but blowdowns within the cypress groves are rare. Knees emerge from a tangle of roots that appears to anchor the entire stand against windthrow.

Chris, Jordan, Maggie, Lane, Jim, and Tong with the ancient one
species interactions
The global distribution of tree seed production

The global distribution of tree seed production

A forest’s ability to regenerate after devastating wildfires, droughts and other disturbances depends largely on seed production. Findings from two new studies led by Duke University and INRAE (France’s l’institut national de recherche pour l’agriculture, l’alimentation et l’environnement) researchers could boost recovery efforts by providing foresters with new guidance on which trees species produce more seeds and how their productivity varies from place to place. [more]

Regeneration of forests devastated by multi-year drought and fire depend on
a vastly diminished seed supply. a) Seed production is limited to unburned
landscape fragments in the Sierra Nevada mixed conifer zone following
2020 burns. b) Total reproduction includes not only seeds, but also defenses, including
wood, spines, and resin flow in conifer cones; examples from the heavily
burned Sierra Nevada and Coast ranges include Calocedrus decurrens, Pinus
albicaulis, P. contorta, P. coulteri, P. flexilis, P. lambertiana, P. monophylla,
P. monticola, P. ponderosa, P. radiata, P. sabiniana, Pseudotsuga menzesii,
Sequoiadendron giganteum
, and Tsuga mertensiana. Photo credits: James S. Clark and Jordan Luongo.

Limits to Reproduction and Seed Size-Number Trade-offs That Shape Forest Dominance and Future Recovery,” Tong Qiu, James S. Clark et al. Nature Communications, May 2, 2022. DOI: 10.1038/s41467-022-30037-9

Globally, Tree Fecundity Exceeds Productivity Gradients,” Valentin Journé, James S. Clark, et al. Ecology Letters, April 23, 2022. DOI: 10.1111/ele.14012

National Science Foundation

Duke coverage

EurekAlert!

Phys.org

Science Daily

Ecology Letters: Fecundity increases two orders of magnitude from boreal forest to wet tropics

Ecology Letters: Fecundity increases two orders of magnitude from boreal forest to wet tropics

Online this week in Ecology Letters: In MASTIF, the discovery of a 250-fold increase in seed abundance from cold-dry to warm-wet climates, driven primarily by a 100-fold increase in seed production for a given tree size. This 100-fold gradient in seeds per tree size is amplified to a 250-fold gradient by the predominance of larger trees in the wet tropics. The modest (threefold) increase in net primary production (NPP) across the same climate gradient cannot explain the magnitudes of these trends. The increase in seeds per tree can arise from adaptive evolution driven by intense species interactions or from the direct effects of a warm, moist climate on tree fecundity. Either way, the massive differences in seed supply ramify through food webs potentially explaining a disproportionate role for species interactions in the wet tropics.

NPP shows a 3-fold increase from boreal to wet tropics, while seeds per tree basal area (ISP) increases 100-fold, and seeds per forest area (CSP) increases 250-fold.

Journe, V et al. 2022. Globally, tree fecundity exceeds productivity gradients. Ecology Letters, DOI: 10.1111/ele.14012, pdf: EcologyLetters2022.

Dr. Ruben Palacio

Dr. Ruben Palacio

Ruben defended his thesis today, entitled “Strengthening conservation of biodiversity at local and regional scales“. This highly successful analysis of conservation issues for the Columbian Andes has already generated important publications, including:

Hazzi NA, Moreno JS, Ortiz-Movliav C, Palacio RD. 2018. Biogeographic regions and events of isolation and diversification of the endemic biota of the tropical Andes. Proceedings of the National Academy of Sciences 115:7985–7990.

Palacio RD, Kattan GH, Pimm SL. 2020. Bird extirpations and community dynamics in an Andean cloud forest over 100 years of land‐use change. Conservation Biology 34:677–687.

Palacio RD, Negret PJ, Velásquez-Tibatá J, Jacobson AP. 2021. A data-driven geospatial workflow to map species distributions for conservation assessments. Diversity and Distributions 27:2559–2570.

Palacio RD, Valderrama-Ardila C, Kattan GH. 2016. Generalist species have a central role in a highly diverse plant-frugivore network. Biotropica 48:349–355.

Palacio RD, Vidal-Astudillo V, Cárdenas G, Luna-Solarte J. 2017. Aves del municipio de Santiago de Cali, Valle del Cauca, Colombia. Biota Colombiana 18:228–238.

Dr. Ruben Palacio, PhD Ecology
Becky Tang: Student paper award from the Amer Statistical Assoc

Becky Tang: Student paper award from the Amer Statistical Assoc

Becky is recognized for her paper, “Modeling spatially biased citizen science effort through the eBird database” in Environmental and Ecological Statistics. This paper also received the Best Award from the Department of Statistical Science.

Tang, B., J. S. Clark, and A. E. Gelfand. 2021. Modeling spatially biased citizen science effort through the eBird database. Environmental and Ecological Statistics, https://doi.org/10.1007/s10651-021-00508-1.