2001: New York City's Vegetational History - Climate Change and Human Impact

Climate is the most important factor that controls the growth and distribution of plants in any region. Pollen grains, containing the male reproductive cells of plants, provide a signature that we examine to reflect what particular plants are growing in any region. They are released into the atmosphere every spring and summer as the plants flower.

Pollen grains are identifiable to a particular species or genus of a plant, are extremely resistant to decay, and are produced in great numbers. Thus the accumulation of pollen over time serves as a record of the present and past vegetation of the designated area in which the pollen is preserved.

Through counting 300 pollen grains/sample, we learn about percentage changes of vegetation types over time. Wetlands are an excellent repository of pollen because the environment is anoxic and the pollen is completely preserved for thousands of years. Thus results of pollen analysis in any one area provide a record of climate in any region.

The history of vegetation in the New York metropolitan region is at this point unknown. To address the question of how New York's vegetation has changed over time, we obtained two sediment cores from Jamaica Bay marshes, an important urban wetland archive which contains pollen of the region. Jamaica Bay is also a very important ecological resource for New York, as it filters water, buffers the region from storms, serves as a nursery for the Hudson Estuary, and provides nesting area and food for millions of migratory birds.

Our pollen team has developed a protocol for identifying and counting pollen, and this summer we are building on our previous record from JoCo Marsh, Jamaica Bay. We are continuing our counts from JoCo Marsh, counting pollen from a second core, Yellow Bar Marsh, and then reading any relevant literature concerning the last 500 years of vegetational history for the region. This includes important climate intervals such as the Little Ice Age as well as human impacts such as European deforestation of the landscape. We will date changes in our cores using radiocarbon dates on seeds. We will plot our new results and interpret the data in light of the available northeastern US literature.

Guiding Science Questions

What is the history of New York's vegetation over the last 500 years?

Can we see climate change in the record of vegetation change in Jamaica Bay marshes?

How does human impact change the record of vegetation that we see in the marshes?

How does the record from Joco Marsh compare with the record from Yellow Bar Marsh?

Can we see a Little Ice Age response of the plants to climate change?

Basic Science Concepts and Questions

• Climate Change
• Paleoclimate
• Plant Ecology
• Wetlands
• Radiocarbon
• Stratigraphy
• Anthropogenic Impacts
• Pollen and Spores

Specific Science Problems

Jamaica Bay Marshes are rapidly disappearing (see NYT 07/06/01). These marshes hold a history of vegetation and climate change for the New York area. We want to document the vegetation and human history contained in these marshes to understand the record preserved in them. We focus on comparison of the western and eastern part of the Jamaica Bay Marshes, Yellow Bar and JoCo. The major climate and human impact intervals of interest, which include (1) the time of marsh formation, (2) the Little Ice Age, (3) arrival of Europeans and deforestation, and (4) reforestation of the region.

Research objective include

• Analyze the Yellow Bar pollen samples to compare with JoCo pollen samples and interpret the results according to the outlined intervals.
• Focus on the Little Ice Age, its representation in the Jamaica Bay Marshes, and its possible occurrence regionally in Eastern North America.
• Complete the JoCo counts, analyze the data and write a manuscript for journal submission.
• Outline a curriculum for a science research course.

Task and Responsible Research

Developing skills and understandings for pollen research: Literature review.

The team will build a literature review based on a collection of summer articles. Each team member will be responsible for identifying key facts of one of the intervals of interest: (1) the time of marsh formation (Dorothy), (2) the Little Ice Age (Rosanna), (3) arrival of Europeans and deforestation (Gloria), and (4) reforestation of the region (Eglantina).

Focus: What are key pollen types in the marshes and how do they change over time? Is there evidence in the pollen record from different northeastern regions for of all four intervals of interest?

• By Week 2 - read Fuller (1998) on Mass. and summarize key aspects
• By Week 3 - read Clark (1986) on Long Island and summarize key aspects
• By Week 4- read Heusser (1975) on Long Island and summarize key aspects

Little Ice Age

Rosanna will be counting the pollen between already counted intervals and will investigate a possible Little Ice Age response in the JoCo core. Rosanna will fill in the missing information to complete the JoCo pollen graph. She will interpret the results within the context of a possible vegetation response to the Little Ice Age.

Focus: What species might indicate cooling? Is there a vegetational response to the Little Ice Age in the JoCo core?

• Week 1 - Count three slides from JoCo. Read paper: "Impact of Human Activity on Regional Forest Composition and Dynamics in Central New England." And get relevent LIA articles.
• Week 2- Count three slides. Read Clark paper. Research documented history of LIA in northeastern US Relevant questions: (1) What are the typical signals of cooling in the northeastern US? (2) What have other investigators found about the LIA?
• Week 3- Complete counts. Fill in information for JoCo in graph. Interpret/analyze graph. Look for possible LIA response. Relevant questions: (1) What type of pollen is associated with the LIA? (2) What date can we give to the LIA (if found)? (3) If LIA is not found, why was it not present?
• Week 4- Prepare for final conference.

Yellow Bar

Gloria will research the count the Yellow Bar core pollen samples, and analyze this data, focusing on a comparison with the JoCo core, and looking for evidence of human impact and the Little Ice Age in this core.

Focus: What impact do humans have on vegetation? What evidence of human impact exists in the Yellow Bar core? How does the Yellow Bar core compare to the JoCo core?

• Week 1 - Count three slides (0-2cm, 20-22cm, 40-42cm). Read the first research article and outline the effects of human impacts on that region.
• Week 2- Count three more slides (60-62cm, 80-82, 100-102cm). Read the second research paper and focus on the arrival of the Europeans. Relevant questions: (1) What type of vegetation is typical of Jamaica Bay and Queens, NY (2) What type of pollen is in the Yellow Bar core? (3) How did humans influence the landscape surrounding Jamaica Bay? 4) What pollen signals show signs of deforestation?
• Week 3- Count three more slides (120-122cm, 140-142cm, 160-162cm). Read the third research paper and analyze human influence on the vegetation in the paper.
• Week 4- Prepare for final conference. Make the list of the top 10 pollen species. Construct a graph of the Yellow Bar samples and analyze the graph for any indication of human impact in Yellow Bar. Relevant question: What impact do humans have on vegetation? (Focus on urbanization, decrease in forestry, increase in ragweed, introduction of foreign pollen types, reduction of native pollen types.)

Synthesis of Jamaica Bay Core Information

Dorothy will finalize the counts. Gloria and Rosanna will plot the counts on excel as each slide is finished. Eglantina will begin to write a manuscript for journal submission based on the pollen counts and macrosamples from the JoCo core. Dorothy will provide feedback throughout the process.

Focus: Can we identify the four periods of interest in this core? What are some key features of each time period? How do our results compare to others reported from the Long Island area?

• By week 2 - Dorothy, Gloria and Rosanna will have counted some slides and entered some data. Dorothy and Eglantina will discuss the macrosample results. Eglantina will outline the manuscript, and read some background information on the Jamaica Bay Marshes.
• By week 3 - Dorothy and Rosanna will continue counting. Gloria and Rosanna will produce graphs with the pollen counts. (The graphs will be made each time a new slide is entered). Eglantina will work on drafting the introduction and methods to the manuscript.
• By week 4 - Eglantina will draft the results section. Gloria and Rosanna will provide the necessary graphs. Dorothy will enter the data into Tilia. The team will draft a discussion section. Prepare for final conference.

Science Research Curriculum

Leila, Umit and Eglantina will outline a research course curriculum for high school students. The proposed course will include one-year of skills acquisition (through lectures, lab activities and short-term projects) and a second year of independent research by the students. We will outline the skills acquisition curriculum.

Focus: What skills do students need to do science research? What activities will help students gain this knowledge?

• Week 1- Identify broad topics/skills to be covered in the course. Outline subtopics.
• Weeks 2 and 3- Identify available activities or describe activities that can be used for each topic/skill.
• Week 4- Compile an organized outline of the skills and topics students would need for the research course, followed by a description of a lesson plan or project that would help in acquiring this knowledge. Prepare for final conference.

Team products

The team will produce a literature review of the summer articles.

Gloria will produce results and graphs from the counts of the Yellow Bar core. She will also try to produce a rough draft of her Intel application materials based on her summer research on the Yellow Bar core.

Rosanna will produce a graph of the completed JoCo counts.

The team will produce an interpretation of the results of both cores, and write a discussion for a final paper.

Dorothy and Eglantina (with Gloria' and Rosanna's help) will produce a manuscript for journal submission.

Leila, Umit and Eglantina will finalize an outline of the research course curriculum.