The ecology, conservation, and land use changes surrounding vulnerable plant mutualisms and natural community types
Plan Author
- Andrea Terrell, 2017
Fields of Concentration
Sample Courses
- Agroecology
- Course: Plant Reproductive Biology
- Tutorial: Ecological History of New England
- Tutorial: Comparative Ecology
Project Description
The achlorophyllous orchid, Wullshlaegelia calcarata, and its relationship with leaf litter mats and the fungi within.
Faculty Sponsors
Outside Evaluator
Overview
This Plan is a study of the relationships between plants and their fungal symbionts in a tropical system, and examples of how land-use history impacts present-day natural communities. It includes a paper about the conservation of pollinator and mycorrhizal mutualisms with plants from temperate to tropical ecosystems, and a field study on the ecology of an achlorophyllous orchid in the tropical montane forests of the Luquillo Experimental Forest of Puerto Rico. It also includes an accompanying exhibition of photography, titled “Stewards of Our Land,” observing the everyday life of small-scale organic farming in rural New England.
Excerpts
In the case of pollination mutualisms, it has recently become clear that threats made against these systems will have biome level repercussions on plant biodiversity and even genetic diversity, both in wild and crop plants. For instance, the honey eater Myzomela rubratra, native to Guam, is now completely missing from the island, leaving the native plant Bruguiera gymnorrhiza without its main pollinator. It was then found that B. gymnorrhiza individuals living on Guam have a reduced seed set compared to other individuals located outside of Guam, which could then affect the distribution of the plant and therefore the composition of natural ecosystems on Guam. Similar scenarios are playing out throughout the world, where plant distributions are changing as a result of reduced pollination, as well as other environmental factors related to climate change and habitat destruction.
Relationships between orchids and their fungal symbionts are often complicated. It has frequently been suggested that Wullshlaegelia calcarata orchids have obligate associations with leaf litter decomposer fungi. Therefore, we were surprised to have found almost no relationship between orchid growth, orchid reproduction, and leaf litter mat parameters. We hypothesized that larger leaf litter mats held more nutrients that then became available to the orchid through the fungi. Further, we hypothesized that orchids with access to more nutrients would have greater reproduction, meaning more flowers, fruits, and viable seeds.
The most common natural disturbances in Marlboro forests are tree deaths creating canopy openings, blow-downs due to hurricanes or ice storms, snow and ice mechanical weight, as well as pests and diseases. The 2008 ice storm that hit the north east caused a lot of damage to the Marlboro forests and even years later, signs of this damage can still be seen. The tops of many trees throughout the forest were broken during the storm and stand as the main signifier of this particular storm, as well as many other downed trees. As for diseases, beech bark disease appears to be fairly common among American beeches in Marlboro forests, particularly near Ridge and Town Trails, and could be a main contributor to American beech deaths within this landscape. Each one of these disturbances allows for the opening of canopy gaps, which then creates the conditions needed for tree seedlings and herbaceous plants with low shade tolerance to germinate.