Dr. Tanisha Williams

Climate change is causing some plants to flower earlier

Contributed by Tanisha Williams @T_Marie_Wms


Africa, Biome, BIPOC, Climate change, Directional Selection, Ecology, Environmental change, Evolution, Field, First generation, Fynbos, Global patterns, Natural history, Natural selection, Observational, Plants, Race/ethnicity, Woman



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Williams, Tanisha. 2018. Old Data, New Insights. University of Connecticut 3 Minute Thesis Competition. https://naturesplasticity.weebly.com/science-videos.html



Slide 1: Researcher’s Background

Tanisha is a botanist and plant ecologist. She completed her master’s work at the California State University Los Angeles. She used population genetic methods to study the hybridization patterns of three Populus species found throughout California and Nevada. Dr. Williams then obtained her PhD from the University of Connecticut. Her dissertation work took her to South Africa to examine the impacts of climate change on Pelargonium plants using herbarium records, common garden experiments, and species distribution models. She is currently working as the Burpee Postdoc Fellow in Botany at Bucknell University. Some of her research includes understanding how biogeographic barriers impact species distributions, updating the conservation status of rare plants using population genomics methods, and working with a dynamic team to examine the role indigenous peoples have on plant genetics, ecology, and how this relationship shapes anthropology in the Northern Territory of Australia. Dr. Williams also has a passion for communicating science and the importance of botanical and international research, and this includes volunteering and advocacy. She is the founder of #BlackBotanistsWeek, an online initiative to highlight Black people, as well as BIPOC, who love plants.


PB: Why did you become a biologist?

TW: I love learning new things and I love answering my own questions! Biology allows me to continue to grow and ask so many questions about how the world works. It is an amazing job!


PB: What is your favorite part about your job?

TW: I love field work! There is nothing like traveling to a new country, waking up before dawn to drive and then hike to a plant population, measure morphological traits, take plant tissue samples, or whatever else is involved in the research I am doing at the time. The best way to know a plant is to hang out with it in its natural habitat!


PB: What obstacles have you overcome to get where you are?

TW: I have overcome being the only Black person, the only woman, and the only Black woman in many spaces. This lack of representation can be tough and also puts a burden on you. I have often felt I have had to prove myself to my colleagues. With many paths comes imposter syndrome and it is something I am still working to combat with every new job, project, etc. I can now look back and see how far I have come and that helps calm the nerves and gives me the push to keep going.


PB: What advice do you have for aspiring biologists?

TW: Never, ever, ever give up on your dream! Also, if you see someone in a job you want or working on a cool research project email them and ask questions about their paths to science and their current job.


PB: Do you feel that any dimension of your identity is invisible or under-represented/marginalized in STEM?

TW: Yes. I am a Black woman in STEM 


Slide 2: Research Overview

Take home message of study

Climate change is impacting species composition across the globe. From 1900-2009, South Africa has undergone a 2.9 degree Celsius increase in mean annual temperature. Associated with this increase in temperature flowering dates of over 100 Pelargonium species have advanced by 7 days.


Study system

This is a collage of what it was like to do research in South Africa! The plant pictures (top left) are all Pelargonium species, native to South Africa. The top right is a photo with me and undergraduate students working at the greenhouse in Cape Town, South Africa. Bottom pictures are of me (left to right): looking at herbarium species used in the research highlighted here, greenhouse set up, collecting plant morphological measurements out in the field (for another research project), and the last two pictures are of greenhouse work.  

Slide 3: Key Research Points

Main figure

This figure shows the association between flowering date of Pelargonium species (y-axis, Day 1 = July 1) and temperature (x-axis; temperature in C). Pelargonium species show a negative trend toward advancing flowering times by 2.4 days per 1 degree C increase in temperature throughout the Cape Floristic Region and surrounding regions (R2 = 0.37).

Societal Relevance

Plants are apart of everything we do – breathing, eating, medicines, clothing – just to name a few ways in which we use and interact with plants. Understanding how plants are responding to climate change is crucial to saving species of critical concern and can also help us prioritize ecosystems in need of conservation.

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