Undergraduate news

Novemeber 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:

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!