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Teaching Notes

In this Section

Grade Level

Interpreting several data sets and providing a valid conclusion requires a higher level of cognition. However it is not required that the students find or manipulate their own data sets. This can be adjusted for students in higher grade levels who can manipulate data in MS Excel spread sheets as well as download data from the source.

Learning Goals

After completing this unit, students will be able to:

  • Analyze data sets and figures to interpret differences in past, present and predicted future climate data.
  • Create and interpret scatter plots within a spreadsheet program.
  • Use data to make valid conclusions and predictions.
  • Describe climate change affects apple tree growth in New York State using appropriate content vocabulary


New York State’s ClimAID report states that New York’s Climate has changed and will continue to change. This climate change is predicted to increase the temperatures in New York State, which will harm cold temperature crops. The agricultural industry in New York State contributes 4.5 billion dollars annually to the state’s economy. Over 75 million acres are devoted to farm use, covering approximately one fourth of the land in New York. New York has been known for its state fruit, the apple.  New York ranks second in the United States in apple production, producing approximately 29.5 million bushels of apples annually. Apple trees are vulnerable to an increase in summer and winter temperatures, and changes in the length of the apple-growing season. Some varieties of apple trees are more susceptible to a change in climate than others. The state’s largest apple crops, the Empire and McIntosh apple, are particularly threatened by rising temperatures. How the apple growers plan their orchards in response to this predicted increase in temperature will determine the future success or failure of the apple industry in New York State.

Key Concepts and Vocabulary

Climate: Climate is commonly defined as weather averaged over a long period of time; the standard is to average data over 30 years. Climate encompasses data from temperature, humidity, wind, atmospheric pressure, precipitation and other meteorological measurements over a long period of time. It is affected by latitude, terrain and location relative to bodies of water. Various climates are classified according to their average and typical ranges of meteorological characteristics.

Climate Models: Climate models use quantitative methods to simulate the interactions of the atmosphere, oceans, land surface, and ice. They are used to study the dynamics of the climate system and make projections of the future climate.

Weather: The state of the atmosphere at a place and time as regards to heat, cloudiness, dryness, sunshine, wind, rain, etc. Weather is daily, and defined at the moment.

Frost: Frost is the deposition of water vapor from saturated air, usually on surfaces. Frost occurs when the temperature of solid surfaces are cooled to or below freezing (0°C, 32°F). Many plants including the buds on apple trees can be damaged by frost. 

Growing Season: The length of the growing season is described as the number of days between the last frost of spring and the first frost of winter, when native crops can grow.

Hardiness Zone: Hardiness zones are geographically defined areas where a specific category of plant life is capable of growing, as defined by climate conditions.

Chilling Requirement: Chilling requirement is the minimum period of cold weather required after which a fruit-bearing tree will blossom. This is often referred to as chill hours. Chill hours are calculated by adding the number of hours from November 1st to January 1st when the temperature is below 45°F (7.2°C).

Heat Damage: Too many days over 90°F (32.2°C) will harm apple trees or their fruit.


  • Relationship between the survival of trees and hardiness zones, chilling requirements, seasonal last frosts and growing seasons. This requires a basic knowledge of climate and temperature change over time.
  • Climate is not synonymous with weather.
  • Hardiness zones depend on the lowest temperature of the year.
  • Chill hours are closely tied to the hardiness zone but are not synonymous.
  • The last frost in the spring and the first frost of the autumn control the growing season.
  • As the spring weather warms it creates a window where late frosts occur. This increases the risk of premature budding that is often killed or severely damaged by a late frost. This hinders fruit production for the year.
  • Temperature and weather are large factors that affect tree growth and success of a species, but they not the only factors. Precipitation, extremes in weather, cloud cover, pests and weeds play a role in the growth of trees; however, the focus of this activity will be temperature and precipitation change.
  • The change in climate does not indicate the end of agriculture and the apple industry. Mitigation and adaption measure exist, for example changing the type of apple tree grown.

Background Information

Tree fruit production is usually located in regions with 150 frost-free days and a U.S. hardiness zone of at least five. Apple trees are no exception, and New York’s climate currently provides those requirements.

The apple industry in New York State is second in the United States behind Washington State. New York produces apples in three major regions: the Hudson Valley, Champlain Valley and the southern shore of Lake Ontario. Apples thrive in these areas because of the proximity to large bodies of water. . Large bodies of water benefit apple trees because unfrozen bodies of water remain warmer than the surrounding air, reducing winter damage. Conversely in the spring, orchards along large bodies of water stay cooler than the air surrounding them, which helps counter warm air. This reduces the potential damage from a late frost and delays the premature bloom of apple flowers. In the spring and fall the lake affect creates a buffer against extreme weather conditions.  Lakeside orchards typically remain cooler during the summer reducing the amount of days above 90F and corresponding heat damage. Apples prefer a steady predictable weather pattern throughout a year; extreme weather patterns threaten the growth and success of apple orchards throughout the state. Scientists predict that climate change will cause the regional climate to become more variable and extreme. In terms of apples this means more frequent and intense rainstorms and droughts. Apples are more tolerant to wet seasons than droughts; however with wet seasons come apple scab, damage to foliage and other diseases. As a whole apples require 114cm (44.88 in) of water between April and August with a preferred interval of water every 7-10 days.

Most commercial orchards are comprised of six different varieties that are grown in large quantities. These six varieties are chosen based on the survival requirements of apple trees. Of those survival requirements, hardiness zones, precipitation, and the temperatures through the growing season are vital to the long term success of apple trees. Hardiness zones focus heavily on trees’ ability to withstand the minimum temperatures of a region. Ten degree Fahrenheit levels split hardiness zones and the USDA has determined that there are approximately 11 different hardiness zones (Table 1).


Table 1: Hardiness Zones

Hardiness zones are not uniform over an entire state; New York State currently has nine different hardiness zones (Figure 1). Each hardiness zone is representative of the differing climates within the state.

NYS Hardiness Zones 


As the temperature changes it is unlikely that it will change uniformly over the entire state. Therefore, the hardiness zones and popular apple producing locations will change at an individual rate. The areas of concern for changing hardiness zones are those where the most apples are currently produced. Apples are produced in larger quantities next to New York’s three largest bodies of water: along the Hudson Valley, the southern shore of Lake Ontario and the Champlain Valley. New York State Apple Growers Association states that the largest apple crops come from the following counties: Clinton, Wayne, Ulster, Orleans, Niagara, Dutchess, Onondaga, Orange, Monroe and Columbia. These top apple producing counties are highlighted in green in Figure 2 below.

NYS Counties 

The higher the temperature, the higher the hardiness zone number, and the warmer the growing season temperature will be. The average annual minimum temperature or the coldest temperature of the year for each year averaged over 10 years is used to classify hardiness zones. As the minimum temperature increase the hardiness zones will increase as well. Tree species are typically classified by hardiness zones. Similar to hardiness zones apple trees require chill hours. Apples have the highest chilling requirement of all trees. Apple trees (variety dependent) require between 600 and 1000 chill hours. The growing season may not determine the survival of an apple tree; however it does dictate how well they produce fruit. Growing seasons are usually determined by climate and elevation. Growing seasons define plant selection. Depending on geographical locations, temperature, sunlight hours and rainfall are critical factors. The length of a growing season determines what crops can be grown in a region. Some crops require long growing seasons while others have short growing seasons and mature rapidly. Heat in the summer negatively affects growth and fruit production. When temperatures exceed 90 degrees Fahrenheit apple trees experience heat stress. Heat stress reduces the photosynthesis process and stunts the growth of trees and fruit. The increase in the number of consistent days above 90 degrees Fahrenheit is an indicator that the location receiving the constant strain of higher temperatures will not remain a suitable location for apple trees.  The number of days over 90 degrees Fahrenheit is another way to indicate rising temperatures during the summer season. A summarized table of the popular apple varieties and their required climate conditions is provided In Table 2. Students will find this information in the apple fact sheet.  If required, they can find additional information in the following resources.

All climate predictions used in this activity are made by a climate model. Models run various scenarios based on possible outcomes of the way the population continues to use our resources. What is referred to as an A1 scenario bases the modeled projection on a global and economic focus, where the population continues to use our fossil fuel resources extensively; this is the worst case scenario used here. A B1 scenario has a global and environmental perspective with a focus on reducing global carbon and greenhouse gas emissions. B1 scenarios run models based on the assumption that we reduce our carbon output and work towards a more environmentally friendly way of life. This is the best case scenario.

Table 2: Popular apple varieties and their required growing requirements.
The water requirements are valid for all varieties. 

Table 2

Other Resources:

Tree Information as well as a “find our hardiness zone” tool

Climate data for New York State (and other North East States), current and future predictions

Wikipedia Definition and general information about climate

New York State Apple Growers Association: Fast Facts on Apple Production in the state

Instructional Strategies

General Approach

Before beginning the activity students must have a solid understanding of the difference between climate and weather. Students then must learn aspects of plant growing requirements including hardiness zone and growing season. They must understand the relative importance of hardiness zones and growing seasons to plants and trees.

This activity can be completed without Internet or computer access; color printed copies of data could be provided. Students will be able to accomplish more, at a more challenging level, if they are able to access the Internet to find their own data and tree information. Students may work alone or with a partner on a computer. With Internet access students will be able to find their own data, look up their hardiness zone and others for New York State, as well as investigate trees in addition to those provided and their own climate data. A logical flow chart for the project is shown below in Figure 3. As shown the fundamental project requires the students to choose apple varieties for their apple orchard that account for expected changes in climate over the next several decades. 


Unit flow diagram



Anticipatory Set Ask students, “What do trees need to survive and produce fruit?”  Record/post their answers on board. Try to separate their responses into categories: natural factors (weather or climate related) and human influences (fertilizer, pest control etc.). Guide the discussion/ student responses towards climate, growing seasons and hardiness zones. On the board add any important factors and notes that students didn’t come up with and that will aid them with the activity of designing their own orchards.

Procedure Student ability level dependent, gather information on each climate factor necessary from one of the provided sources and the instructions included alongside the example of a modeled orchard for New Hampshire. There are several formats where students may gather data, some requiring more time or cognitive development. Upper level students can access data directly from the North East Climate Data web page following the instructions in NEClimateData_Tutorial.doc

Reviewing the maps provided by the Northeast climate data website are a good way to review a wide range of climate data.  For apples, the critical indicators to consider are:

•          Hardiness zone

•          Days over 90°F

•          Growing season length

Additional MS Excel data are available to supplement some of the data. The data in Historical_Last_Frost_Data.xls, Last_Frost_Data.xls and Precipitation.xls files provide numerical values for the amount of precipitation as well as data that aren’t provided on Northeast Climate data. These data files can be manipulated and graphed by the students. The data contained in these files is also graphed and contained in separate worksheets within these documents as an alternative if time, student ability/interest, or familiarity with Excel is a constraint.  For those without internet access the PowerPoint document Data_for_Students.ppt has the necessary information for students to complete the assignment.

Students should be able to complete the activity on their own. However, some may need guidance. Note – the teacher may provide the data source and a set of instructions on how to retrieve their own data, and students can find what they need. Figure 4 provides an additional visual resource for students to follow.

Case Study Flow Chart

Optional – to expand their thinking have students choose another location in New York State with a different climate and compare the orchard they created to those that exist already. For example: an apple orchard in New York now, an orchard in New York in 2050 and a current orchard in California.

Closure Have the class compare their orchards, and discuss their findings such as the types of trees, locations within New York State. What is the expected (predicted?) hardiness zone of Northern New York, and how much change, if any, should people expect to see in their apples choices?  The discussion should yield the following conclusions:

  • The hardiness zones in New York State have already changed by going up a hardiness zone; hardiness zones are not the same throughout the state and will change at different rates as well.
  • According to the IPCC Model if the temperatures continue to rise as they currently are, the hardiness zones in Northern New York will raise another hardiness zone interval.
  • Some varieties will survive the predicated hardiness zone change for 2050. However there are other trees that will be better suited for the changing climate. Also the popular regions for apples may change within the state. Students should be able to define specific apple tree varieties that will be affected, such as McIntosh apples, along the southern shore of Lake Ontario.

Learning Contexts

The activity could be done alongside a biology unit where the other factors that go into the success of a tree are investigated, such as cell growth and photosynthesis, and how these would be influenced by increasing temperature and changing climate.

To emphasize the change in climate and how much it affects the types of trees and plants grown in a given area, the activity can be done alongside a world studies or geography lesson. Teachers would be able to have students chose a remote, unfamiliar location and find out what factors affect climate, and what agriculture is like compared to what they’re familiar with.

One major factor in building an orchard is the expense. The activity of building an orchard can be tied into a math unit by giving the students a budget to follow and prices of trees and other expenses.

Science Standards New York State 1996 edition: Commencement level

Standard 4: Students will understand and apply scientific concepts, principles, and theories pertaining to the physical setting and living environment and recognize the historical development of ideas in science.

Key Idea 6:1- Explain factors that limit growth of individuals and populations

Key Idea 6:3- Explain how living and non-living environments change over time and respond to disturbances.

Standard 7: Students will apply the knowledge and thinking skills of mathematics, science and technology to address real-life problems and make informed decisions.

Key Idea 1:3- Design solutions to real world problems on a community, national , or global scale, using technological design process that integrates scientific  investigation and rigorous mathematical analysis of the problem and the solution.


A completed orchard design, including location, apple tree choices and brief descriptions of why each choice was made should be written up and handed in for grading.

Other Resources

Apple Fact Sheet

This resource is a fact sheet to give to students before completing the activity. It provides any necessary background information for completing the activity so that the students do not need to search for it in other locations.

Student worksheet and instructions

Excel spreadsheets with weather data


Last frost date in spring

Summary presentation file with map results (to use if internet access not available or for younger students.)

Data Sources

North East Climate historical data and predicted climate:
Northeast Climate data tutorial