Crow Soil Ecology & Biogeochemistry Lab

M.S. student, Casey McGrath, turned on the heaters for her deep soil warming experiment at Lyon Arboretum in Manoa this week.  She says “Here is a snippet from one of the five heater’s temperature sensors (at 60 cm) from the live feed of data: http://grogdata.soest.hawaii.edu under “Lyon” tab.”  The protective effect of the non-crystalline minerals abundant in volcanic ash-derived soil predominant in the back of Manoa under the Tantalus formation is about to be tested. Here is a link to her blog post, check it out!

In the “Best Halloween Costume Ever” category – our fabulous departmental fiscal
support staffer, Megan, actually dressed up as a Crow Lab graduate student!!! I seem to have a bit of a reputation around here (well earned, I suspect, soil biogeochemistry cannot be done without thousands of sample analyses, I mean, come on!).  Happy Halloween!

…continued from the previous post.

On the Whispering Winds farm hosting us to determine the soil carbon profile under bamboo, laying the grid and prepping the sample bags was the easy part.  Two fearless graduate students (above), some hired muscle from a neighboring farm, and my dearly devoted husband spent the following two days slugging 24 1-m soil cores from the volcanic soil.  As always, nothing goes as planned and a broken corer meant most of a day spent searching for a machinist in Hana to repair it while simultaneously seeking acceptable food for an 8 year old boycotting the local vegan fare.  Yes, science is a family affair for us, which adds extra dimensionality to the career activities of dual-academic couples (but, that is for a different post).

We may have sampled fewer profiles and sometimes to a more shallow depth than desired. And, it sure would have been nice to have been on that outbound flight (I apologize again, Mokulele Airlines, you all are the best for dealing with us) rather than drive the Hana Highway at top speed (ha!) to make the connecting flight in Kahului.  But, we made it back to Oahu where I could start separating each sample into roots, rocks, and soil.  The soil is destined for carbon measurements needed to create the desired 3-D soil carbon profile.  After several days: my nostalgia for lab work has worn off, I’m only 2/3’s done as the semester begins, and now a threatening hurricane is upon us.

To be continued…

The diversity of climates, biomes, and soils in Hawaii is as great as the communities, producers, and management practices that utilize the landscape there.  The possible combinations of all these factors are numerous, which presents a challenge when providing recommendations for best land use and management practices to optimize economic and environmental returns.  Nonetheless, an opportunity exists now to reconceive Hawaii’s agricultural systems as a critical part of achieving simultaneous state goals for carbon neutrality, 100% renewable energy, and increased local food production.

Building soil health and resilience into the landscape through diversified agricultural and managed systems is a critical climate action – one that will drawdown carbon from the atmosphere and reduce greenhouse gas emissions from the land surface. How much climate change mitigation a system may bring varies, and recently a colleague asked our research group to study the soil carbon associated with bamboo.  The non-invasive, clumping bamboo varieties are beautiful and selected for building materials and landscape purposes.  But, do they also sequester carbon belowground? Last weekend, we crossed some of our diverse managed landscapes on Molokai in a tiny plane bound for Hana, Maui to make some measurements.

To be continued…

@ElaineViska joined the lab this summer to expand our work on soil health and carbon sequestration in Hawaii.  A new data synthesis and networking grant from USDA NIFA for a web-based soil health and carbon assessment, monitoring and planning tool will support her Ph.D. work.  Elaine comes from Iowa State University with a strong foundation in the principles of soil health as well as field, lab, and GIS skills.  We are excited for her soils expertise and look forward to the coming years of collaboration on a project with great meaning for Hawaii, where re-conceived farming systems play a critical role in collective climate change action and building resilience into the island landscape.   

Congratulations to Jon Wells for advancing to his Ph.D. candidacy this spring.  Jon successfully defended his proposal “Understanding carbon in large-scale agricultural production systems for bioenergy in the tropics: selecting soils, feedstocks, and conversion pathways” and will continue his soil, plant biopolymer, energy, and carbon investigations towards the completion of his degree.

Getting back to my academic origin this week, I found myself in one of the remaining pristine environments in Hawaii – Pepeopae on the island of Molokai.  Pepeopae is a mountain top wetland protected within the Kamakou Preserve by The Nature Conservancy.  Aside from a stray “naughty deer” this week, the wetland is ungulate and invasive plant species free.  This magical place resembles wetlands worldwide from the United Kingdom to Svalbard – commonalities exist in the form and function of plant communities and sensory experience of the wet ground, cool humid air, and color palette. Why is this wetland here, why doesn’t the water drain down the mountainous terrain?  A clay layer exists in the bottom of the peat, is it a buried spodic horizon or a shrink-swell clay layer that swelled and never shrank under a suddenly wetter climate 14,000 years ago?

 

From machete to soil pit to thesis proposal, congratulations to Casey McGrath for her successful defense of her proposal to conduct a Deep Soil Warming Experiment in Andisols at the Lyon Arboretum in Manoa.

Casey and Hannah demo taking a 1 m soil core by auger to share with our forestry partners.  Check out the tutorial videos here.