F/RS 310
Assignment #7
Shrub Identification Key
47 Points Possible
Introduction
The identification of species in natural ecosystems is a required skill in managing natural resources. If the species cannot be identified, then important ecological functions also go unidentified and management strategies may not accurately match the system of interest. One way to gain the skills of identifying species is through memorization of large sets of species that you may encounter during your career. However, another way to identify species is through the use of dichotomous identification keys. A dichotomous key presents a series of 2 choices that lead users to the identification of a species. At each step in the key, the user must choose between the two choices and then follow the key to the next set of ‘clues’. It’s kind of alike a ‘choose your own adventure’ book, if you ever read those as a kid. There are identification keys for a wide range of regions and organisms that can help you identify any species you encounter regardless of where you get a job in the future. Another way I have found to learn species AND learn about using keys is to create a plant identification yourself. This forces you to closely examine a set of species, which often results in long-term memory of these species. Creating a key is also a great critical thinking exercise, and by creating a key yourself, you will have a better understanding of how they can be utilized.
Objective
The objective of this assignment is to have you become familiar with a set of 9 shrubs species that are common to a wide range of ecosystems in the western US. In addition, you will become familiar with how to use a dichotomous key to identify different species of plants.
Student Learning Outcomes
After completing this assignment you will be able to:
- Site-identify 9 different species of shrubs
- Create a simple plant identification key
- Utilize technical terms to distinguish between different species of shrubs
- Describe key functional attributes of key shrub species in the western US
Description of Assignment
In order to get full credit you need to:
- Create a dichotomous key to identify 9 shrub species
- You must use the standard format for dichotomous keys (refer to the deciduous tree key we used in lab for reference)
- Use at least 15 unique technical terms to describe the leaf shape, leaf margins, leaf color, leaf attachment, and/or bark characteristics. You must use the following terms in your key: Deltoid, obdeltoid, bifoliate, filiform, canescent, striate, pinnately divided, fascicles, spinescent. Make sure to underline all the technical terms you use to help us in grading the assignment and ensure that you get full credit. Also, since ‘technical term’ is a bit subjective, please ask me if you have questions about the terms that will qualify for points in this category.
- Include a description of the region where each species occurs: You must reference the deserts that each species occurs and then any other information about its distribution beyond the 4 deserts we’ll discuss.
- You must include information on each species’ forage quality, rooting characteristics, and ability to resprout. You can find information about these characteristics at: https://www.feis-crs.org/feis/faces/SearchByOther.xhtml
- Cite any sources that you utilize in creating your key, including the website listed above.
NOTE: Do not use flower or seed structures in identifying shrubs. Use only leaf and stem characteristics.
Rubric (47 Points Possible)
- Include 9 shrub species in your key (9 points)
- Utilize at least 15 technical terms in your description of these 9 species (15 points)
- Include information about the rooting characteristics, resprouting ability, forage quality, and distribution of each species (18 points)
- General organization of key (can I work through it easily)? Does numbering make sense? Is it in the dichotomous key format? (5 points)
Shrubs species to include in your key
- Ambrosia deltoidea
- Ambrosia dumosa
- Artemisia fillifolia
- Artemisia frigida
- Artemisia tridentata
- Atriplex canescens
- Chrysothamnus viscidiflorus
- Larrea tridentata
- Sarcobatus vermicilatus
TERMS YOU MUST INCLUDE IN YOUR KEY:
Deltoid, obdeltoid, bifoliate, filiform, canescent, striate,
pinnately divided, fascicles, spinescent