
Exercise 2: Measurement of Local Diversity
Module 2: Introduction to Local Biomes
Your Questions
- Are there characteristic species assemblages present in the local communities?
- How can local biodiversity be measured?
- Does local biodiversity vary with spatial scale?
Background
The Atlantic forest of Brazil is a complex formation that originally extended over 3000 km from the south of Brazil, in the state of Rio Grande do Sul, along the coast north to the northeast region, states of Pernambuco and Alagoas. The distribution was basically on the mountains along the coast, but there were enclaves further inland. The site where we will starting this course, the Morro de Diabo, is a State Park with a total area of over 35,000 ha and has several different kinds of plant formations, including Atlantic forest enclaves and deciduous mesophytic forest.
Generally, the plant diversity is considered to be high in this formation (Atlantic forest) and, as in many tropical forests, there are no dominant species. For a general reference on the diversity of plant and other species that have been cataloged for the state of Sao Paulo, access the Tropical Data Base web site (http://www.bdt.org.br).
In this lab we will look at the relationship between spatial scale and diversity, with specific reference to the plant community. Many past studies have shown a relationship between these factors for a wide range of species and communities. More information can be obtained in your text (Wilson and Perlman)
Your Assignment
- Identify and describe different plant community types
- Define sampling strategies for estimating diversity in different plant communities
- Locate sampling points
- Measure local plant diversity at different spatial scales
Methodology
Task A Recognition of local plant communities
- Visit to the principal plant communities, by car and on foot on pre-existing paths.
Task B Measurement of local plant diversity in different community types
- Characterize local plant communities based on their physiognomic characteristics (average height, % ground cover, number of layers, deciduousness, etc.)
- Localize sampling point (or points) in each community type
- Establish sample plots
- Count, identify individuals in each plot
- Increase the size of the plot and repeat measurements
Task C Data analysis and write up
- Data entry into computer
- Estimate local diversity in each community type
- Summarize results for presentation (written and oral)
Objectives
- Study the of spatial distribution of local plant communities
- Present basic field orientation techniques
- Acquire information on local plant diversity
- Present concepts of diversity and scale effects
- Introduce concept of biodiversity
- Present concepts on how to classify communities
Key Skills
- Learn basic field orientation techniques compass and GPS
- Learn basic field safety
- Acquire knowledge of the distribution of local community types
- Learn how to classify plant communities
- Understand concepts of measurement of alpha diversity
Timetable
Total time 2 days
- Morning - Day 1
- Visit to field sites for general overview
- Discussion of distinguishing plant community attributes
- Choose field sites for data collection
- Afternoon - Day 1
- Practice in establishing sampling quadrats
- Practice in use of GPS and compass
- Establish sampling quadrats
- Practice of data entry
- Practice in data management
- Morning - Day 2
- Data collection at field sites
- Afternoon - Day 2
- Data entry and analysis
- Write up of report of activities
Procedural Notes
As with most field work, you should use appropriate clothing. This includes long-sleeved shirts and long pants to protect from insect bites and general scratches. Also, since the course is being held in the winter in Brazil, a jacket or sweater may be necessary.
Remember to bring repellent, especially for ticks and chiggers.
Materials Needed
- Local maps
- Field notebook and writing equipment
- Compass and GPS
- Tape measures (50 m)
- Quadrat marking equipment (stakes, cord, flagging)
- Plant collection equipment