海角论坛

March 8, 2018 鈥�  of the Georgetown 海角论坛 has been awarded three grants to study the impact of climate change and natural disasters on springtime emergence of plant, bird, and insect species.

The grants, all awarded by the , will allow Ries鈥� team to analyze information on the timing and nature of various species鈥� spring emergences, the migration patterns of monarch butterflies, and the impact of storm-related flooding on monarch butterfly habitats.

AN ACCESSIBLE ICON

According to Ries, the monarch butterfly makes for a great research subject because of its history as a public icon of conservation and its accessibility to average Americans.

鈥淚 don鈥檛 think there鈥檚 a single species that鈥檚 as closely monitored as the monarch,鈥� Ries said. 鈥淢ost of the species that are focused on in conservation efforts are charismatic megafauna, like polar bears or wolves. You don鈥檛 actually see those. But you can capture a monarch, bring it home, raise it 鈥� people really get involved.鈥�

This accessibility makes it easy for volunteers to participate in citizen science projects, in which researchers like Ries rely on a network of volunteers that provide the observations for their analyses.

鈥淭here are people who monitor the migration, people who tag the butterflies, people who look at the eggs as they develop into larvae and pupa, people who sample them for disease,鈥� Ries said. 鈥淚t鈥檚 kind of amazing, and we can use it because it鈥檚 so widespread and happens every year.鈥�

Two of the grants Ries鈥� team has received focus specifically on monarchs to understand what biotic and abiotic factors most influence their annual migrations and population dynamics.  Both focus on using volunteer data from across the country  as they make their journeys from their northern breeding grounds throughout eastern North America to Mexico. While the butterflies are in many ways a unique species 鈥� an insect that conducts a multi-generational annual migration across a continent is a rare thing 鈥� their behavior can help scientists understand the changing climate.

鈥淚t鈥檚 a model system for understanding large-scale ecological patterns, because there鈥檚 so much data,鈥� Ries said.

AFTER THE STORM

Funded by a $55,000 grant, Ries will bring her own team to the Houston area to examine how monarch habitats have changed in the wake of Hurricane Harvey, which devastated the region last August.

Storms like this can change when milkweed 鈥� monarchs鈥� host plants 鈥� appear, which has repercussions for the butterfly migration that scientists don鈥檛 fully understand yet.  Precipitation also drives nectar availability in the fall, a critical component of successfully migrating to Mexico.

鈥淲e know something unusual was going on this fall that was probably related to the hurricane, but we don鈥檛 know yet if it matters,鈥� Ries said.                    

Ries鈥� team has begun setting up plots in Texas and examining satellite imagery to determine the distribution of milkweed and is beginning data collection in mid-March. Ries is unsure what exactly she鈥檒l find there, but she suspects the flooding will have mixed effects on monarch habitats.

鈥淭he influence on their nectar plants, if any, is probably positive. But the influence on the host plants is probably negative,鈥� Ries said. 鈥淗arvey caused more milkweed growth, which prompts the monarchs to interrupt their reproductive cycle and lay eggs in Texas. And those caterpillars won鈥檛 survive.鈥�

ECOLOGICAL INTERACTIONS

Another $330,000 grant will allow Ries to study the timing of ecological events, like spring budburst and bird arrival, in a collaboration with of the .

鈥淏ecause there can be differences across groups in reaction to climate change, we鈥檙e looking at what happens when the shifts aren鈥檛 equal,鈥� Ries said. 鈥淚f the birds show up and there鈥檚 no caterpillars, are they able to be successful? If caterpillars show up when there are no birds, do they do better?鈥�

There is a large existing body of literature on the impact of climate change on individual species鈥� emergence and some looking at two or three interacting species, but studies that examine how changes in timing of emergence interact have been limited in scope. Ries and Arab’s team hopes to change that.

鈥淲hen you look at individual species, you鈥檙e just asking who鈥檚 doing a good job adapting and who鈥檚 doing a bad job, and the implications of that are often more straightforward,鈥� Ries. 鈥淏ut when you look at interactions between multiple species, it starts to get more complicated to predict what will happen.鈥�

Once again, she鈥檒l be relying largely on data from citizen science projects, and birds in particular draw large numbers of volunteer data. In one project, Ries and Arab鈥檚 team will use data from the past two decades to build models predicting birds鈥� emergence and distribution based on climate. They鈥檒l attempt to 鈥減redict鈥� bird emergence from past years 鈥� as far back as 1910 鈥� based on this data.

鈥淚t鈥檚 a very different climate now, so if these historical model predictions do pretty well, we can be a lot more confident in the predictions we make for the future,鈥� Ries said.

UNDERSTANDING A CHANGING CLIMATE

Ries sees her research as vital in helping people understand the impacts of climate change and major weather events on complex ecological systems.

鈥淓vents like Hurricane Harvey are becoming more common and more severe, so we should be considering them in our global ecology model,鈥� Ries said. 鈥淎t the end of the day, it鈥檚 about trying to understand the outcomes of choices we make right now,鈥� Ries said.