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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

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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.

Chase Nunez evaluates climate change in central African forests

Chase Nunez evaluates climate change in central African forests

To evaluate the response of diverse Afrotropical forest communities we employ country-wide tree species inventories, remotely sensed climate data, and future climate predictions collected from 104 one-ha plots in the central African country of Gabon. We predict a 3–8% decrease in Afrotropical forest species richness by the end of the century, in contrast to the 30–50% loss of plant diversity predicted to occur with equivalent warming in the Neotropics… [more]

Winning and losing tree species under two climate change scenarios, accounting for dependence between species.

Nunez, C.L., J. R. Poulsen, L.J.T. White, V. Medjibe, and J. S. Clark. 2021. Distinct community-wide responses to forecasted climate change in Afrotropical forests. Frontiers in Ecology and Evolution, nunezFEVO, https://doi.org/10.3389/fevo.2021.719141.

Shubhi Sharma leads tree migration study in PNAS

Shubhi Sharma leads tree migration study in PNAS

Suitable habitats for forest trees may be shifting fast with recent climate change. Studies tracking the shift in suitable habitat for forests have been inconclusive, in part because responses in tree fecundity and seedling establishment can diverge. Analysis of both components at a continental scale reveals a poleward migration of northern species that is in progress now. Recruitment and fecundity both contribute to poleward spread in the West, while fecundity limits spread in the East, despite a fecundity hotspot in the Southeast. Fecundity limitation on population spread can confront conservation and management efforts with persistent disequilibrium between forest diversity and rapid climate change. [more]

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Sara Roberts on fisheries responses in Scientific Reports

Sara Roberts on fisheries responses in Scientific Reports

Sara Robert’s new paper shows how the community of fishes responding to environmental change: “Single species distribution models (SSDMs) are typically used to understand and predict the distribution and abundance of marine fish by fitting distribution models for each species independently to a combination of abiotic environmental variables.” [more]

Roberts, S.M., Halpin, P.N. & Clark, J.S. 2022. Jointly modeling marine species to inform the effects of environmental change on an ecological community in the Northwest Atlantic. Scientific Reports 12, 132. https://doi.org/10.1038/s41598-021-04110-0.

Niche shifts from adults to fecundity to regeneration for North American Forests

Niche shifts from adults to fecundity to regeneration for North American Forests

Tree distribution and abundance depend not only on climate, but also on habitat variables, such as soils and drainage, and on competition beneath a shaded canopy. Using conditional models to compare the communities represented by joint fecundity and recruitment responses we expose a reorganization across life stages that will contribute to the next generation of forests. Tree fecundity is regulated by temperature to a greater degree than other life-history stages. Recruitment rates are most sensitivity to interactions between climate and habitat variables. Communities reorganized from adults to fecundity, but there is a re-coalescence of community types as seedling recruitment partially reverts to community structure similar to that of adults…[more]

Joint sensitivity taken over all species for adult abundances, conditional recruits (left y-axis with black color), and fecundity (right y-axis in green). Sensitivity is shown as a fraction of the total variance explained for each variable. Posterior medians are show with 95% credible intervals (whiskers).
Map of community assemblages (A) and reorganization as an alluvial diagram (B). Community clustering in (A) is based on adult tree response matrix. (B) Shifts in assemblages across the three demographic stages (adult, fecundity, and conditional recruits) in eighty-seven species.

Qiu, T., S. Shubhi, C. W. Woodall, and J.S. Clark. 2021. Niche shifts from trees to fecundity to recruitment that determine species response to climate change. Frontiers in Ecology and Evolution 9, 863. https://www.frontiersin.org/article/10.3389/fevo.2021.719141, DOI10.3389/fevo.2021.719141.