# Presentation: 538852

## Green-Down Protocol

## Goals for the Training Session

- Provide an inquiry context for the data collection and science content
- Provide accurate science content
- Review procedures for data collection
- Review data entry and analysis
- Discuss classroom implementation ideas
- Collect feedback from participants

**Notes:**
These are the goals for the Green-Down Measurement Protocol training session.

## Inquiry Context

- How long does green-down take for a given species?
- How does the green-down differ between different species?
- How does green-down relate to air temperature?
- Does green-down differ from year to year for the same tree/shrub?

**Notes:**
Budburst generally signals the beginning of the growing season for many plant species, while green-down and leaf senescence marks the end of the growing season. This period varies by species and by latitudinal location, as well as by influencing factors such as temperature and soil moisture availability. 

The series of pictures in this slide show green-down and leaf drop for a Sweetgum Tree (Liquidambar styraciflua) at the Cartersville Primary School in Cartersville, Georgia, US.

Questions for further investigation:
-What other animals (butterflies, waterfowl, songbirds) migrate after plants green-down? When? Why?
-Does the timing of green-down occur earlier or later at higher elevations in your region? Why--?
-Does the timing of green-down occur earlier or later inland or near the coast in your region? Why?
-How do fallen plant leaves affect soil properties such as soil color, water-holding capacity, and soil nutrients? How could you find out? Why is this important?
-How does the green-down of grasses relate to air temperature? To soil temperature? To precipitation? To soil moisture?

## Local Inquiry Example

**Notes:**
Students can generate local inquiry questions to create a context for data collection to answer the question. Local inquiry topics can be connected or scaled to provide a local to global perspective on environmental research.

To provide the local inquiry context you might want to first determine what study areas are available and which species are the dominant tree and shrub species in the town or in the region. 

Please generate a local example that teachers and students can relate to.
Examples: 
How long does it take leaves of different species to change color and drop?
How does green-down vary within a tree?
How does the green-down of the understory species differ from the overstory species in your study area?

## Why do GLOBE scientists research green-down?

- To calculate growing season length and monitor interannual changes in growing season duration
- To determine how environmental conditions such as air and soil temperature, soil moisture, and day length affect plant growth
- To monitor the nature and extent of climate change and its effects on plants and animals
- To help interpret satellite observations of greenness

**Notes:**
The length of the growing season is a very important indicator of global and regional climate change, especially if recorded across many years. By using satellite data, scientists have discovered that the growing season has increased in many areas of the world (mainly mid and upper latitudes) in the last 20-30 years, by as much as 8-12 days!
Having green-up data and other forms of phenological data, scientists can compare measurements of growing season determined by satellite data to actual measurements taken on the ground. These ground-truth data lend greater credibility to scientific findings made using satellite data that may vary because of problems due to atmospheric properties, sun angle changes, poor viewing geometry and aging of satellite detectors.
Growing season data are also used extensively in climate and ecological models. Scientists test their models against real data of growing season length to help them determine how accurate the models are able to predict the real circumstances found in the environment.  

The picture shows trainers practicing how to use the GLOBE Plant Color Guide to determine the color value for leaves undergoing phenological change in the Fall. Leaf color change from green to yellow, orange, red or brown, or when leaves fall, is used as an indicator of the end of a plant growing season 

## Science Content: What is green-down?

**Green-down** marks the end of the growing season for many plants. A color change is generally associated with green-down of leaves.  The color will vary by species.

- November
- 1987

- July
- 1987

**Notes:**
After green-down, and its associated color change, leaves often drop off the plant.

The graphics on this page show the Normalized Difference Vegetation Index (NDVI), or amount of vegetation greenness, as calculated from the National Oceanic & Atmospheric Administration (NOAA) satellite data for two months in 1987.  These data are from the National Aeronautics and Space Administration (NASA) and the Goddard Space Flight Center (GSFC). The scale bar indicates that a larger NDVI value relates to greater amounts of green vegetation, as measured by light reflectance to the satellite instrument. The changes between these two months represent the period of green-down. This green-down period varies from year-to-year, and scientists closely monitor this trend to determine how it has changed over a long time period, and how it relates to environmental and climate changes.

## Instruments: Green-Down

- GPS Receiver
- Local Tree/Shrub Identification Guide
- GLOBE Plant Color Guide
- Compass
- Meter stick or tape measure (for grass study site)
- Camera
- Flagging Tape & Marker

**Notes:**
A local tree/shrub ID guide can help in identifying the genus and species.  You may want to consult local experts.
Use the flagging tape and a permanent marker to identify the branch and tree/shurb or grass shoot which will be observed.
During actual observations only the data sheets, a pencil or pen, and the plant color guide are needed.

The picture shows a trainer determining the color code of leaves using the GLOBE Plant Color Guide.

## The Measurements

- Green-Down Study Site Definition
- GPS location
- Tree/shrub species or grass genus
- Study Site pictures
- Green-Down Protocol
**For tree or shrub:** date, leaf condition and leaf color on four leaves of the same branch
**For grass:** date, shoot condition and shoot color on the four tallest shoots

**Notes:**
The Green-Down Study Site can be done at the Land Cover Study Site, the Atmosphere Study Site, or at a separately defined site.
If doing both Green-Up and Green-Down, using the same Study Site is preferred. This supports better student and scientist research.
The Green-Down Study Site should be easy to access since students will need to visit at least twice a week.

The picture is of a study site at the Jordan Small School in Raymond, Maine, US taken during the fall green-down period.

## Collecting Data: Field\Lab Guides & Data Sheets

**Field\Lab Guides:**
- Tree and Shrub Green-Up and Green-Down Site Selection Field Guide *or* Grass Green-Up and Green-Down Site Selection Field Guide
- GPS Protocol Field Guide
- Tree and Shrub Green-Down Field Guide *or* Grass Green-Down Field Guide
**Data Sheets:**
- Green-Up and Green-Down Site Definition Sheet
- GPS Investigation Data Sheet
- Tree, Shrub and Grass Green-Down Data Sheet

**Notes:**
Field/Lab Guides: The respective chapter and pages numbers are included below:
GPS Field Guide is located in the GPS Investigation of the Teacher’s Guide.  
-GPS Protocol Field Guide (GPS Protocols – 9)
-If needed: Offset GPS Protocol Field Guide (GPS Protocols – 10)
Green-Up/Green-Down Field Guides are located in the Earth System Science Investigation:
-Tree and Shrub Green-Up/Green-Down Site Selection Field Guide (Green-Down Protocol - 4)
-Grass Green-Up/Green-Down Site Selection Field Guide (Green-Down Protocol - 5)
-Tree and Shrub Green-Down Field Guide (Green-Down Protocol - 8)
-Grass Green-Down Field Guide (Green-Down Protocol - 9)
Data sheets: The data sheets are located in the Appendices of the GPS Investigation and Earth System Science Investigation of the print Teacher’s Guide or they can be downloaded from the Teacher’s Guide link on the GLOBE Web site at any time.
-GPS Investigation Data Sheet (GPS Appendix – 3)
-If needed, Offset GPS Measurement Data Work Sheet (GPS Appendix – 4)
-Green-Up/Green-Down Site Definition Sheet (Earth System Science Appendix – 3)
-Tree, Shrub and Grass Green-Down Data Sheet (Earth System Science Appendix – 7)

## Collecting Data: Green-Up and Green-Down Study Site

_**Site Selection**_
- At least 2 weeks before budburst
- Convenient location
- Native trees/shrubs or grasses that are not watered or fertilized are preferred

_**Tree and Shrub or Grass Selection**_
- Identify dominant tree and shrub species or grass genus
**For Tree and Shrub:**
- Select one dominant, native, deciduous tree/shrub
- Select and flag a healthy, good-sized branch on the equator-facing side
**For Grass:**
- Select a one-meter square area dominated by grass plants

**Notes:**
For site selection:
You can use a preexisting Land Cover Sample Site if easily accessible for frequent plant phenology observations. You can create another site/ other sites. 
Since the results of this protocol can be combined with temperature and precipitation data, try to choose a site close to your Atmosphere and Soil Moisture Study Sites.
Needs to be easy to access because students need to visit at least twice a week and continue until leaf color changes from green, to yellow, orange, red, or brown, or falls off.
Avoid sites near buildings or where watered, fertilized or impacted by other human activities, if possible. If not possible, be sure to include conditions in the site metadata.
Sites with native trees/shrubs or grasses are preferred.

For tree/shrub selection:
For the phenology measurements you should choose a deciduous plant species in the area/region.  If the dominant plant species are all evergreen conifers, use the under-story broadleaf shrubs as your green-down plants.
Scientifically, it is most useful if the tree or shrub branch used for the Green-Down Protocol is the same as the one used for the Green-Up Protocol. 
In the northern hemisphere select a south-facing branch; in the southern hemisphere select a north-branch, use a compass to help you determine the correct side of the tree to flag.

## Collecting Data: Protocol

- Photograph your site
**For Tree or Shrub: **
- Locate and mark leaf at end of selected branch
- Locate and mark three other closest leaves
**For Grass:**
- Locate the four longest green grass shoots.
- Mark the base of each grass shoot.
_**Every Visit**_
- Determine dominant color for each leaf or grass shoot
- Or report either:
- 		Snow Covered or Fallen

**Notes:**
Students should visit the Study Site at least twice a week to check for the start of green-down, and continue observing until leaf changes color from green to yellow, orange, red or brown, or falls off. 
Photograph from the center of your site looking in the north, south, east, and west directions.

Continue recording tree/shrub leaf or grass shoot/blade color until it stops changing colors across several visits (at least three visits) or leaf falls occurs. Different leaves and shoots may stop changing at different dates.
In the Northern Hemisphere, the number of growing season cycles is generally equal to 1, starting after January 1st. Some areas in the subtropics and tropics, or areas dominated by wet and dry cycles, may have more than one growing season. 

**At this point, pass out the handout of the Example of Completed Data Sheet.

## Enter Data on the GLOBE Web Site Green-Up and Green-Down Study Site Definition

- Step 1: Select “Define a Green-Up/Green-Down Study Site” from the Phenology data entry menu
- Step 2: Enter the Study Site information
- Step 3: Click “Send Data” button
- Step 4: Confirm data entries on verification page

**Notes:**
**At this point, direct the participants to the GLOBE training data entry site and have them enter the data from their data collection sheets. 
You can choose to enter Green-Down data after each observation, or enter all the data after you have finished making all observations of Green-Down.
You can define the site beforehand or at the time of data entry.
Email data entry is also available.  Directions can be found on the GLOBE Web site under Data Entry.

It is always a good idea to include metadata, or additional information, about both the study site and the green-up observations when entering data. Especially for the study site it allows you to better describe where the study site is (i.e., is it a forested setting, is it in the front school bus turn-around, is it on the edge of a road or marsh, etc). 

How to submit Site Photos:
Site photos can either be submitted electronically or by mail.
For instructions on how to do this see page 35 of the Implementation Guide Appendix of the GLOBE Teacher’s Guide. This can be accessed from the GLOBE Web site.

## Enter Data on the GLOBE Web SiteGreen-Down Protocol

- Step 1: Confirm that a Green-Down Study Site has been defined
- Step 2: Select “Green-Down” from the Phenology data entry menu
- Step 3: Select your Study Site, enter the date and growing season cycle
- Step 4: Enter data for the status and color of the leaves from each line of the data sheet, one at a time
- Step 5: Confirm data entries on verification page

**Notes:**
**At this point, direct the participants to the GLOBE training data entry site and have them enter the data from their data collection sheets. 
Email data entry is also available.  Directions can be found on the GLOBE Web site under Data Entry.

Green-Down data has to be entered one line of the data sheet at a time. After you submit data for one day of observations, you have to go back through the full data entry process by either clicking on “Enter More Data for Green-Down” link on the Verification Page, or by Selecting “Green-Down” from the Phenology Tab of the main data entry page.
It is always a good idea to include metadata, or additional information, about the green-down observations when entering data. A textbox space is provided for entering this additional information.

## Looking at the Data

- Comparison of Green-Down Data
- of Two Species
- Worthen C of E Primary School, Shropshire, United Kingdom

- Leaf 1

- Leaf 2

- Leaf 3

- Leaf 4

- How does the green-down differ between species?

**Notes:**
These data address “How does the green-down differ between different species?”  Ask your audience what observations they might have?
Several different observations can be made from these data:
There is a color change difference between the two species. Birch (Betula pendula) greens down to a yellow color and then leaves drop, while Beech (Fagus sylvatica) greens down to a yellow, and then further to brown with a later leaf drop.
The initial leaf color differs between species.
The leaf color appears to vary more within the beech tree than within the birch tree (i.e., the 4 leaves of birch appear more similar).
Leaf color change appears to occur earlier in beech then it does in birch.
Dead (brown) leaves stay on the beech tree, where as leaves of birch drop off before they brown.

This particular school has multiple Green-Down Study Sites using several different tree species. Additional comparisons can be made by accessing their data on the GLOBE web site. These data are best visualized by using the GLOBE Maps & Graphs displays specific to the phenology data sets. You can access data like this by going to the GLOBE web site, clicking on the “Maps and Graphs” link on the Table of Contents sidebar, then clicking on the “GLOBE Sites” link, then clicking on the “Green-Up/Green-Down Site Visualizations” link. You can then choose a school in a country of interest.

Refer to the “Looking at Data” section of this protocol in the Teacher’s Guide for a data analysis activity.

## Classroom Implementation

- Inquiry
- Curriculum/Standards Alignment
- Assessment
- Classroom Management

**Notes:**
Have participants break into groups and discuss one or more of the following bullet items, as time allows.

Learning Activities for the Earth System Science Investigation include:
(these can be downloaded from the GLOBE web site from the “Earth as a System” chapter, under the Teacher’s Guide Link):
Seasons
S1: What Can We Learn About Our Seasons?
S2: What Are Some Factors That Affect Seasonal Patterns?
S3: How Do Seasonal Temperature Patterns Vary Among Different Regions of the World?
S4: Modeling the Reasons for Seasonal Change
S5: Seasonal Change on Land and Water
Phenology
P1: Green-up Cards
P2: A Sneak Preview of Budburst
P3: A First Look at Phenology
P4: A Beginning Look at Photosynthesis
P5: Investigating Leaf Pigments
P6: Global Patterns in Green-up and Green-down
P7: Temperature and Precipitation as Limiting Factors in Ecosystems

## Getting Started

- The GLOBE Web site has information
- _[http://www.globe.gov](http://www.globe.gov/)_
- GLOBE Help Desk or your Country Coordinator can support you as you get started.
- Get your students involved doing real science!

**Notes:**
A first step in being prepared to implement the phenology protocols is to fully read through the Phenology Introduction section of the Earth System Science Investigation, in the Teacher’s Guide.
Secondly, an exploration of the possible study sites available and the tree/shrub species that can be observed, well before green-down, will help you be prepared to make these measurements.
Multiple sites can be established and observed!
Don’t forget to enter your data soon after completing the observations! Maintain a hard copy of your class/school’s data.
Use the GLOBE data & visualization tools on the GLOBE web site to see what other schools are recording for phenology.