Glossary of Terms

A

Abiotic

The term abiotic refers to the non-living components of ecosystems, including such things as rocks, soil minerals, air, and water.

B

Biotic

The term biotic refers to the living components of ecosystems, including soil micro-organisms, plants, animals, and diseases.

C

Cryptobiotic crusts

Cryptobiotic crusts are formed on soils by microbial organisms. These living crusts are dominated by cyanobacteria (also known as blue-green algae), fungi, lichens, and mosses. Cryptobiotic crusts are found throughout the world and play an important role in the high desert ecosystems of the Colorado Plateau. Crusts may appear as slight ridges of less than 1 mm high to dark knobby features up to 5 cm high. More developed crusts may have visible patches of lichens and mosses growing on the outside. Careful examination will reveal the filamentous structure of cyanobacteria that form an intricate web just below the soil’s surface. These filaments are incased in a sticky sheath which helps hold soil particles and resists erosion. When these filaments are wet, they can swell up to ten times their dry size, providing important water storage accessible to vascular plants. In addition to these benefits, crusts contribute to the growth and germination of vascular plants by fixation of atmospheric nitrogen and nutrient contributions. This is especially important in desert climates where nitrogen and other nutrient availability is low (Belnap 1997). Though cryptobiotic crusts are well adapted to severe growing conditions, they are extremely vulnerable to disturbance. Recreational activities, motor vehicles and livestock grazing can destroy patches of crusts leaving soils exposed to erosion and exotic plant invasion. Recovery from compaction and loss of soil stability may take over 50 years and may be further hampered by moving sediment. Due to the sensitivity of the crusts, soil and nutrient cycles are at high risk within GSENM. For more information on cryptobiotic crusts or cyanobacteria refer to www.soilcrusts.org.

D

Dunal Pocket Communities

Dunal pocket communities are isolated ecosystems formed where sand has accumulated in topographic depressions. These pocket communities contain plant and invertebrate species that are unique to the dunes. These isolated areas are very fragile and intolerant to human-caused disturbances.

E

Ephemeral

The term ephemeral refers to the intermittent nature of streamflow common for many stream reaches. Ephemeral streams flow only during high rainfall periods.

G

GIS

A Geographic Information System (GIS) is a software tool that generates, manages and analyzes geographic information. The user may input various amounts and types of spatial data to the GIS software and create maps, charts and tables. The GIS software may even create new data by combining different data sets the user has entered. Our project uses GIS to create maps that display geographic features, (e.g. watersheds); man-made features, (e.g. trails); vegetation features, (e.g. pinyon-juniper communities); political boundaries, (e.g. grazing allotments); disturbances, (e.g. forest fires); and areas of research, (e.g. sampled plots). Each of these features may include one or more "coverages" which can be overlaid onto other feature coverages. We can then create more specific maps which may focus on a particular theme. For example, we may need to know which areas of pinyon-juniper, within the Monument, have been exposed to fire. The GIS software can take information from the three feature coverages (vegetation features, disturbances and political boundaries) and create a single coverage which would display the new information.

H

Hanging Gardens

Hanging Gardens are mesic habitats which form around springs and moist cracks in the canyon walls of the Colorado Plateau. These rare "island communities" hold unique populations of invertebrate and vascular plants and are extremely vulnerable to disturbance (May 1997).

M

Modified-Whittaker Plot

The Modified-Whittaker plot design is a standardized multi-scale technique for measuring plant diversity (richness) and cover. Derived from the widely used ‘Whittaker plot’, the Modified-Whitaker uses various size subplots nested within each other (Shmida 1984). The design allows for superior estimation of mean species cover, analysis of plant diversity patterns at multiple spatial scales, and trend analysis from monitoring a series of strategically-placed, long-term plots (Stohlgren 1994). For more information on the Modified-Whittaker plot design see our link to our Modified-Whittaker web page.

P

Predictive Modeling

Predictive Modeling is a powerful tool for using our data. The information from our sampling methods is used for multiple regression models (e.g., to figure out what variables are associated with exotic plant species occurrence) and for more complicated spatial models (e.g., use of geo-statistics and GIS data to predict where on the landscape we expect to find exotic plant species). Because no one can afford to sample an entire area, these models can help land managers decide where to spend their limited resources for inventory, monitoring, protection, or exotic species control efforts.

R

Remote Sensing

Remotely Sensed Data is spatial information acquired from a distance. High resolution aerial photographs and satellite images, both used by our research team in GSENM, are examples of remotely sensed data. The satellite images we use are from Landsat Thematic Mapper, spectral bands 1, 2, 3, 4, 5, 6, and 7. Band 6 is a thermal band with spatial resolution of 120m x 120m while the other bands have a spatial resolution of 30m x 30m. Each band, or combination of bands, allow us to determine the vegetation cover types of a study area. The results can then be compared to aerial photographs and field data to provide greater accuracy of vegetation classification. This technique is called double sampling.

T

Tinaja

A Tinaja is a Castillian term which literally means "vessel" or "tank." In geological terms, tinajas describe cavities carved out of monolithic rock which hold precipitation. These water reserves play an important role in desert ecosystems, providing water reserves for plants, wildlife and the indigenous people that once inhabited the land.

V

VMS

Video Mapping System. Our field crews incorporate Video Mapping with each sample plot. This involves filming, with a VMS-200 video camera, the surrounding landscape of each plot, the sampling process, the location marker, and it’s identification number. During the taping, a built in GPS unit simultaneously records the UTM coordinates of the plot. With this information, we can later compare our data with surrounding landscape features, have a backup record of the UTM coordinate and have a visual reference for each plot.