SEE-U 2000: Biosphere 2 - Module 02

Module 2 at:

• | Atlantic Forest (Brazil)
• | Black Rock Forest (New York)

Exercises for Module 2:

• | Measuring Biodiversity

Exercises for Module 2:
Module 2 at:

# Biosphere 2 Center ## Module 2: Introduction to Local Biomes
Printer format Today we begin a two-day study of the local factors that determine the structure of the local biome. As you explore the influences of these factors, you will become more familiar with your local biome. In addition to this ecological content, you will become familiar with Global Positioning System (GPS) units, and we will introduce a valuable tool called eBiome. eBiome incorporates database management software and a Geographical Information System (GIS). We will use eBiome as a data repository and for constructing data inquiries using spatial information. eBiome was created specifically by and for the SEE-U program and is a unique and valuable feature to our classes. You will use GPS units and eBiome almost daily through the course of the semester. ### Local Factors As you’ve probably noticed, there is great variation within any single biome. The same plants are not found on both sides of, or different slope positions on, a hill. As a drainage runs through an area, it greatly influences the composition of the plants and animals that are present. As you approach the nearby mountains, the desert tends to be structured much differently than when you stand in the center of the lowlands around B2C. This set of observations seems to disagree with the range information we tend to find in species identification books. In the eastern US forest, for example, the tree identification guide shows that sugar maple (Acer saccarum) is found throughout the entire northeastern US. In fact these trees do best in deep, rich, well-drained soils in lowland areas and are primarily found below 1,600-m elevation. Furthermore, the young trees or seedlings prefer shaded conditions. If these conditions are absent within the species projected range, the tree will probably not be present as well. Therefore, the factors that provide the local structure of a biome are idiosyncratic and site specific, in contrast to the features that determine which biome generally will be present at any one location. Abiotic forces largely determine the local structure, as with what determines biomes. However, the geographic scales at which these factors operate vary widely, so you must always consider scaling when you study your biome. Examples of abiotic terrestrial factors that structure the local biome include proximity to water bodies, regional variations in rainfall, proximity to cities, topography, and slope. These factors are arranged from those shared over a wider geographic range to those that vary according to a much smaller scale. Within aquatic ecosystems, the features that structure the environment are attributable to the distance from the water surface. These include overall water depth, temperature, salinity, oxygen content, current strength, and light availability. Occasionally, biotic forces can be just as strong as abiotic forces in structuring biomes locally. Keystone species are species whose presence affects the organization of the community (e.g., in terms of plant associations and food web structure) far greater than one would predict based on species numbers or biomass alone. Keystone species are often top predators that control herbivore populations. Keystone species are often top predators that control herbivore populations. For example, sea otters control sea urchin populations in Californian Kelp forests. Other examples include species that extensively modify the physical environment (e.g. beavers) or plant-specific pollinators (e.g. bats). We will further explore the role of biotic factors in Section B and abiotic factors in Section C in your syllabus. ### Navigation Knowing your exact location is essential for conducting ecological studies. Often the best and most informative studies are longitudinal ones—those that involve repeated measurements of the same variables at a site over many years. During the SEE-U program, we will be participating in many longitudinal studies. Most of these studies are possible because the researcher knows her way around with great precision or because the study site is well marked. However, if the study is to be revisited many years later by a novel researcher how would they know where to work? How do we navigate about a biome? Several navigation tools are available, many of which you may have already mastered. Road maps, topographic maps, compasses, navigation using the stars, sextants, and other tools and skills have historically been an integral part of determining where you are when conducting ecological studies. All of these are useful and informative, but none can tell you your precise location with great confidence. Global Positioning System (GPS) Units can accomplish this task in perpetuity and without reference to other supporting materials. Maps, flagging tape, spray paint, marking flags, compasses, and other accoutrements are not necessary. The only tool that is necessary is a GPS unit. These can provide a precise geographic location to within centimeters and altitude to within a few meters, depending on the quality of the units. GPS units work by taking readings from a network of more than 30 satellites that are constantly circling the Earth. These readings are later synthesized using a computer algorithm and the precise location is produced. Georeferenced data are those for which GPS units were used to determine the precise location of the study site. Because of the many benefits posed by the technique, georeferenced data is the future of ecology. ### eBiome We will start to intensively use the eBiome data tool during the next module, but a brief introduction to its utility is appropriate here. Three technologies are the basis of eBiome: GPS, Geographic Information Systems (GIS), and a database management program. GPS is used to determine the precise location of the data, while GIS is a type of software that allows you to organize and access the data by their location and data type. GIS consists of computer hardware and software designed for the input, storage, manipulation, and output of data referenced by a common system of spatial coordinates such as GPS localities. The function of a GIS is to permit data on many sets of variables over a specified geographic area to be combined or manipulated to answer questions about spatial relationships. The GIS enables the results of such analyses, as well as any of the data sets themselves, to be printed out in map form. For example, a GIS might combine data on climate, soils, and slope steepness to create a map of land suitability for a species of concern (e.g., a rare or endangered plant or animal population). The GIS software that we will use is a program called ArcView. Unfortunately, GIS does not allow for easy input for most of our data types. To input the data that we will be collecting during the class, we will use a database program that has been modified specifically for eBiome. We will be using FileMaker Pro for our database program. The steps from collecting data to analyzing it within eBiome are as follows. In the field, you take a location reading with a GPS unit. You process the location information using a program (called Pathfinder) upon your return to the lab. Next, you input the georeferenced data into eBiome using FileMaker Pro. Then the data is transferred to the ArcView component of eBiome. Once they have been linked up with the preexisting data, these data and all others that have been input can be searched and output for other analyses. The benefits provided to you and subsequent students by eBiome are many and unique. You can revisit the same site that another researcher has studied with great precision through the same season and across years, even if you have never been there. You can easily and quickly search all previously collected data by a specific geographic area or by a specific data type. Additionally, eBiome will serve as a central repository for all data collected as part of the SEE-U program. Therefore, you can study other biomes in depth using the raw data that has been collected by students and researchers who are onsite at those other biomes. The data that you will be collecting will be stored and used by researchers who will publish using it. In this way, you will be contributing to ecology, even as you learn it!