Tag Archives: effects of invasives

A Sampling of Forest Ecology Research

15 Jul

This summer I have spent most of my days working as an intern for the Botanic Garden of Smith College under the guidance of Gaby Immerman, assisting the staff there with the maintenance of the various gardens and trees around campus. On Fridays, however, each intern engages in a personal research project in order to create a final product that benefits the Botanic Garden in some way. I am being supported by CEEDS to work with Michelle Jackson, a 2015 graduate of Smith College and a researcher in Professor Jesse Bellemare’s laboratory, on research about the effects of Eastern hemlock tree (Tsuga canadensis) decline on the liverwort species Bazzania trilobata.

Eastern hemlock trees have been in decline as populations of two invasive Asian insects, the hemlock woolly adelgid and the elongate hemlock scale, get established and feed on the trees. In forests in Chesterfield and at Smith College’s MacLeish Field Station in Whately these hemlocks are gradually being replaced by black birch (Betula lenta), changing the composition of the understory, the interactions of various animals, and the forests as whole systems. B. trilobata is associated with Eastern hemlocks, but Michelle is interested in finding evidence as to whether these liverworts are actually dependent on Eastern hemlocks.

thumb_IMG_1273_1024Liverwort Bazzania trilobata

Michelle is testing the effects of different predictor variables on the survival of B. trilobata. Primarily, she is testing the difference between liverworts in areas with hemlock versus patches of forest with birch growth. She is also comparing these results to liverworts growing in areas that have been clear-cut, or those where hemlock trees have been salvage logged. Since hemlocks are coniferous and black birch are deciduous, Michelle is also looking at how being covered by the differing leaf litter affects B. trilobata. Her research takes into account variables such as aspect, slope, radiation, and soil moisture. I have been helping Michelle by flagging plots and making observations about the survival states of samples of B. trilobata.

I have also had the opportunity to help the other researchers in the Bellemare lab with their individual projects. I have helped collect data for Elizabeth Besozzi ’16, who is working to determine the effects of the shift of forests from hemlock to birch on salamanders and the food webs in which they are involved. I have helped collect soil samples for Aliza Fassler ’17, who is looking to see how this same shift in forest composition affects the soil and carbon-nitrogen cycling. I have also gotten the opportunity to help Anna George ’17 prepare tree core samples for her project involving the appearance of an increased spread of magnolia trees (Magnolia tripetala) into locations further north than their typical range.

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Eastern hemlock trees (coniferous), Tsuga canadensis, and black birch trees (deciduous), Betula lenta

I am hoping to write a more comprehensive article about the research going on at MacLeish Field Station, focusing especially on the research surrounding the hemlocks done by those I’ve worked with in Professor Jesse Bellemare’s laboratory. I think that this important research needs to be shared with the public to spread awareness about the impact of the actions of humans on the environment, including climate change and the resulting movement of species to new locations. Furthermore, I believe that this research is an important example of why places like the MacLeish Field Station, are conducive to research and preservation.

Isabella Fielding ‘17 is a rising Junior from Warwick, RI. She is majoring in Biology and English, and she aspires to be a scientific writer

Soil Sampling and Nitrogen at MacLeish Field Station

23 Jul

For the past ten weeks, we have been working as summer interns for professor Amy Rhodes. Some of our work has been collecting soil from forest plots at the Ada and Archibald MacLeish Field Station as part of the ongoing MacLeish soil project which was established in 2012. This soil collection is unique in that we collect from pairs of distinct types of plots: one deciduous and one hemlock. Selective logging in the history of the field station created these side-by-side plots, perfect for research.

Each of the plots we have been sampling from has been divided into seven subplots, delineated by bright orange garden flags and biodegradable twine. Multiple times a week we have gone out to the plots to use a fancy tool we call a soil corer and a fancy storage container we call a cooler with ice packs and brought back to campus upwards of fourteen soil samples to be analyzed and processed in the lab.

Hannah                                               Hannah takes a core sample.

 Cooler                               The cooler with a day’s harvest of soil core samples.

Our major focus has been looking at nitrogen in the form of nitrate and ammonium. Many of the hemlock trees at MacLeish are dying because of two invasive insects: the Woolly Adelgid and Hemlock Scale. This has resulted in a change of the forest ecology as black birch trees gradually take the place of hemlocks. We are looking to see if there is a significant difference between the nitrogen found in the soil beneath the hemlock trees and that found in the soil beneath black birch trees. We use the IC to analyze the total nitrate and ammonium in each of the plots.

Taylor                                     Taylor after a day of coring.

Taylor is in the process of crunching our data with R-Studio. She is deftly tackling the difficulties of working with Excel and is contrasting our time in the field with equal time on the computer. Luckily, the fragrance of the delicious forest air lingers in our nostrils and our recent memories of being outdoors sustain us as we settle down to forge ahead on the inside-on-the-computer portion of our work.

We both agree that ten weeks has slipped by quicker than soil passes through our 2mm sieves. Our time in the field, and in the lab, has been rewarding both in our understanding of data collection and analysis, and in the way a lab setting creates interactions between incredible minds. Soil has appeared to have permanently wedged itself under our fingernails, and while vigorous hand washing may eventually remediate that situation, we will lament its loss, and look forward to another opportunity to get our hands dirty

-Hannah Francis ’16 is an environmental geosciences major and is typically cooking or baking when she is not swimming as a member of the Smith swimming and diving team.
-Taylor Jones ’17 is a biological sciences major, and loves backpacking, being outside and playing with her puppy whenever she can.

Hannah and Taylor’s internships were supported by the Smith’s SUmmer Research Fellowship (SURF) program and CEEDS.