Welcome to new members!

August 2020

The lab is growing! We are thrilled to welcome Maddy Case and Andrew Muehleisen to the lab as postdocs, and Carmen Ebel as a PhD student and Gabby Altmire as a masters student.

Maddy comes to us after completing a PhD with Carla Staver at Yale University studying savanna vegetation dynamics. She will be working on a USDA-funded project studying rangeland resilience and annual grass invasion in the northern Great Basin. Welcome Maddy!

Andrew completed his PhD with Liza Comita at Yale University. In his postdoc he will be studying mechanisms of coexistence and plant community stability, while also working with the UO Data Science Initiative to develop new undergraduate curricula. Welcome Andrew!

Carmen joins us from the University of Minnesota where she researched plant communities at the Cedar Creek Long Term Ecological Research site. Welcome Carmen!

Gabby joins us from Purdue University where she was research technician in entomology and recently completed her bachelors in Biology at Ursinus College. Welcome Gabby!

Lab Retreat 2020

July 28-29, 2020

We had a summer lab retreat on July 28-29. We workshopped our papers over zoom in the mornings - those were very productive mornings! We then wrapped up our retreat kayaking in Fern Ridge Reservior. We enjoyed each other’s company (6-feet apart, of course) and the warm sun. Laura helped us identify some bird species.

HJ Andrews Fieldwork 2020

July 2020

Alejandro, Lina, Paul, Eliza, Cal, and Lauren headed out to Bunchgrass and Lookout Nut Net sites at the HJ Andrews Experimental Forest in Blue River, OR. Thankfully we received university approval during the pandemic to take species composition data and clip biomass from long-term experimental plots treated with factorial additions of nitrogen, phosphorous, and potassium - all while maintaining social distancing!

Hazelnut cover crops are growing!

June 2020

Last fall we seeded native forbs as cover crops in hazelnut orchards managed by the family of recent grad, Marissa. We are investigating whether native prairie plants can survive in a managed orchard context, and provide services such as soil moisture retention and pollinator resources. After a great growing season during which we repeatedly monitored soil moisture, the flowers are up and we are recording community composition and pollinator visits by host plant species.

Next steps are mechanical flailing and scraping treatments to see which of our native species survive!

Congrats seniors!

May 2020

We are so proud of our graduating seniors! We had a great showing at the Undergraduate Research Symposium, with Cal presenting a talk on hogs and hazelnuts, Justin presenting a poster on mycorrhizal fungi in rangelands, and Michaela a poster on N deposition in the serpentine. Plus Marissa gave an excellent finishing talk on cover crops in hazelnuts. Sad we couldn’t say goodbye in person.

Lucky for us Cal will be continuing his research this summer on a Peter O’Day Fellowship with Alejandro and helping as lab manager into the fall.

Plus the undergrads ran the table with UO UROP mini-grants this year, with successful proposal from Justin, Anna, Marissa and Michaela; Marissa and Justin also received UnderGrEBES grants.

USDA Fellowships

May 2020

A big congratulations to Ashley and incoming postdoc Marina LaForgia– both received USDA NIFA Postdoctoral Fellowships, and Marina also received a NSF Postdoctoral Fellowship!

The lab is going belowground - Ashley will be exploring soil biotic communities and Marina will be studying soil seedbanks. Marina will be co-advised with Jennifer Gremer. Excited to start these new projects and collaborations!

Paper roundup

February 2020

Another paper roundup! Alejandro had his first Hallett Lab paper published in the Journal of Vegetation Science, looking at the effect of grazing, spatial heterogeneity and climate on beta-diversity at the Carrizo Plain. Check it here: https://onlinelibrary.wiley.com/doi/abs/10.1111/jvs.12862?af=R

Our R package codyn just received a big update with help from Meghan Avolio. New features make it easier to analyze patterns of community variation over space and time (helpful for Alejandro’s paper, for example!). Check out associated manuscript here (open access): https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.2881

And Lauren was part of big synthesis of CORRE data led by Kim Komatsu in PNAS: https://www.pnas.org/content/116/36/17867

Undergraduate news

November 2019

Congratulations to Elizabeth Baach and Hunter Mackin for defending their theses. Elizabeth’s project focused on litter quality between native and non-native plants on and off ant mounds in a California serpentine grassland - take a look at what she found in her poster below - and Hunter’s project looked at how maternal environments and pathogens affect germination in two common Pacific Northwest grasses. Also check out an update on Cal Penkauskas’s research using pig grazing to reduce filbertworm infestation in hazelnuts in his poster below as well as this article in Around the O. Justin Day presented a poster on his summer research that examined the effects of compost and precipitation on arbuscular mycorrhizal associations with plants - check it out below - and congratulations to Justin for being accepted to the UOTeach master’s program. And a big welcome to Sofi Forsman and Michaela Fishback, who will be working on phenology and trait measurements in Eliza Hernandez’s ongoing greenhouse experiment.

Oregon field season

September 2019

It was a busy first year of Oregon fieldwork. Alejandro kicked it off last fall with his burn and seed additions to test strategies to restore invaded perennial grasslands. His “burn box” generated a lot of buzz amongst local fire crews. Spring sampling showed an initial positive effect on seedling establishment. His next experiment is now in the ground, assessing annual-perennial competition under heat. Meanwhile, Lina made the Great Basin her home last spring in large-scale seed and trait collection survey to test climate adaptation, and her rainout shelters for a common garden experiment are now in the ground in Eastern Oregon.

Welcome Emina

June 2019

Laura Johnson welcomed her first child into the world in December, and the Hallett lab is excited to welcome it’s youngest member!

California field season

April 2019

We had a great California field season this year. We convinced Richard to return for is 37th (!) year, and then celebrated by exploring the superbloom at Carrizo National Monument. Elizabeth and Eliza got to see first-hand the ant mounds underlying shifts in C:N tissue ratios they have been observing in the lab. Ashley was initiated into Loralee Larios and Lauren’s long-term study of grazing on Stipa pulchra at Vasco Cave, and then went off to SFREC to measured the marked effect her compost amendment and rainfall manipulation treatments had on productivity, phenology, and composition.

Congrats Alejandro

April 2019

Way to go Alejandro Brambila, who advanced to candidacy after a great talk, and then was awarded the NSF GRFP. Here’s to some great science ahead studying the resilience of Pacific Northwest perennial grasslands to annual grass invasion under a warmer climate.

Congrats undergraduates

March 2019

The undergrads are crushing it! First, big congratulations to Drew Donahue, who defended a truly excellent senior thesis. Drew explored whether a pig grazing strategy for pest management would have unintentionally harmful consequences in oak woodlands. She worked hard sampling at My Brother’s Farm all summer, and so far the answer is no - limited, late-season grazing seems to be okay. Check it out here: https://www.youtube.com/watch?v=s2FDHS2MYq0&t=1s

Plus Cal Penkauskas and Elizabeth Baach both were awarded UROP mini-grants, and Cal got a SURF summer fellowship!

New papers

January 2019

Lab members had a suite of papers come out this fall. Big congratulations especially to Lina and Eliza, who both had their first first-author papers published!

Eliza’s paper tackles the interacting effects of nitrogen deposition and invasion on fire dynamics in California grasslands. High quality litter should decompose quickly, and fast litter decomposition should reduce fuel loads. Eliza found that N-deposition increased the quality of litter (and this its rate of decomposition) within a species. However, N-deposition also favored an invasive annual grass over a native perennial grass, and the invasive grass has lower quality litter that decomposes more slowly than litter from the native grass. Thus, ultimately N-deposition lead to an increase in fuel loads and fire risk in California. Check it out here:
https://www.sciencedirect.com/science/article/pii/S0140196318301630

In her recent paper, Lina looked at different perceptions of ranchers, managers and academics on “conservation” in California rangelands. Although conservation in rangelands often depends on partnerships among different stakeholders, ranchers, managers and academics had somewhat different views of what conservation means. Rancher’s tended to adopt a Leopold-esque “sustainable use” perspective, whereas managers typical had a more Muir-esque, preservation-focused view of conservation. Academic perception were in between these two views. Land use change was a shared concern among the three groups. Check it out here: https://www.sciencedirect.com/science/article/pii/S0190052818300828

Plus Ashley is pumping out her PhD papers:
Shaw, E. A., C. M. Booth, J. C. Moore, D. H. Wall, J. S. Baron. 2019. Long-term nitrogen addition shifts the soil nematode community to bacterivore-dominated and reduces its ecological maturity in a subalpine forest. SOil Biology and Biochemistry.
Find it here: https://www.sciencedirect.com/science/article/abs/pii/S0038071718304176

And Lauren finally has a paper from Jasper Ridge:
Hallett, L. M., E. C. Farrer, K. N. Suding, H. A. Mooney, R. J. Hobbs. 2018. Tradeoffs in demographic mechanisms underlie differences in species abundance and stability. In press, Nature Communications.
Find it here: https://www.nature.com/articles/s41467-018-07535-w

Plus a new methods paper with Shaopeng Wang:
Wang, S., T. Lamy, L. M. Hallett, M. Loreau. 2019. Stability and synchrony across ecological hierarchies in heterogeneous metacommunities: linking theory to data. In press, Ecography.
Find it here: https://onlinelibrary.wiley.com/doi/abs/10.1111/ecog.04290

Freshwater mussel sampling

September 2018

Laura had a successful freshwater mussel sampling campaign this summer. Field helpers Kennedy, April Dawne, Jemina and Emily worked with Laura to re-sample known mussel beds throughout the South Umqua. Some beds were mussels all the way down, others were almost entirely gone. Laura will be relating mussel population size and age structure with environmental drivers such as flow rates, land development and sedimentation.

Welcome Ashley

September 2018

We are thrilled to welcome Ashley Shaw to the lab as a postdoc. Ashley comes to us after completing a PhD with Diana Wall studying soil communities in Antarctica. She’ll be taking on our new USDA project testing the effect of soil amendments in California rangelands on multiple ecosystem services. Welcome Ashley!

My Brother's Farm field work

August 2018

It’s been a great summer at My Brother’s Farm. Alejandro, Cal, Drew, Naomi, Julia and Taylor sampled filbert worms both as they emerged from the ground and flew in the canopy. The pigs are currently being deployed to test whether pig grazing in the oak woodlands can reduce filbert worm pest pressure on Taylor’s hazelnut stands.

Laura wins poster award

May 2018

Laura’s poster on extinction debts in freshwater mussels won the “Best Content” award at the Annual Joint Campus Conference this year. Congrats Laura!

LTER Synchrony

May 2018

The LTER Synchrony working group had a fantastic third meeting at NCEAS. Excited about the progress, and looking forward to reconnecting at ESA and ASM.

California field season

April 2018

We had a great California field season this year. Richard Hobbs celebrated his 36th year of sampling at Jasper Ridge, Dana Chadwick came out to help us sample, and we caught up with Joan Dudney, Stu Weiss, Lisy Torregrosa, Hal Mooney, Paul and Anner Ehrlich and Val Eviner. Loralee Larios and Lauren celebrated 6 years of Vasco sampling. Alejandro came out to help at Vasco, and then Lina joined us at SFREC. A productive and enjoyable April!