1999: The History of New York's Vegetation and Climate - Ties to the Present

Researchers: Marlene Brito, Katherine Chance, Jennifer Epstein, William Gononsky, Don Overly, Dorothy Peteet, and Jennifer Wong.

Introduction

Throughout each spring and summer for thousands of years, the flowering trees, shrubs and herbs of New York have released pollen to the atmosphere, making sure that the flowers are fertilized to become fruits, and thus that the flora will continue to reproduce the following year. This project captures this natural yearly phenomenon in order to provide a unique snapshot of the composition of Manhattan's vegetation. Because pollen is related to climate on the regional and global scale, one can use this pollen record to characterize the climate of New York, both at present and in the past.

This project builds on the collection and analysis of pollen captured on microscope slides at George Washington High and GISS through the spring and summer season of 1998 and 1999. These records document the importance of oak and pine to the New York area, with the additional signatures of elm, beech, birch, maple and hemlock. This pollen collection thus identifies a suite of trees that is typical of the mid-latitude climate of the US, i.e., a mixed deciduous forest with some pine. In this study, the 1999 Manhattan pollen signature will be extended through the summer season, examine the New York area in the context of the east coast climate and vegetation, and explore the pollen record of New York to the historical and the ancient past.

Research Objectives

This research identifies the short-term and long-term changes in the pollen record and the climate of the New York area by answering the following questions:

• What key pollen types reflect the present climate of the New York City area, and how does that pollen signature differ from other parts of the eastern US?
• How does the Manhattan spring-summer pollen signature of 1999 compare with the spring-summer pollen signature of 1998?
• How has the Manhattan pollen signature changed over the last 100 years, as analyzed from a sediment core taken in Central Park?
• Is there evidence for the elm and chestnut pollen declines in the pollen record?
• What does the pollen record look like in New York 10,000 years ago - a new record from Black Rock Forest wetlands?

Research Tasks

1. Produce a graph of the pollen signature for summer 1999 after pollen counts weekly throughout the summer - compare with 1998 signature.
2. Produce a 100-year graph of pollen counts from the Central Park core - 20 slides at 5-year intervals. Analyze the pollen data to identify any climatic changes or anthropogenic signals that emerge (ie. elm or chestnut decline)
3. Identify and count a 10,000 -yr pollen slide from Black Rock forest wetland.
4. Analysis of New York pollen-climate results in context of east coast of the United States.

Suggested format for carrying out this project:

Week 1: concentrate on learning the major tree types of New York and their relationship to the eastern US and to the climate of the eastern US.
Week 2: concentrate on learning about the early vegetation of Manhattan for comparison with the 100-yr Central Park record.
Week 3: focus on the invasion of non-native plants or weeds and the demise of native plants in all the pollen records.
Week 4: concentrate on the completion of the data, graphics, and analysis of its climatic message.