Transcript
Page 1: Angora Creek CRAM Assessment

Angora Creek CRAM Assessment

Kevin Morgan

Dr. Stevens

Field Methods

November 6, 2014

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Table of Contents

Angora Creek Report………………………………………………………………………………………..............3

Riverine Wetlands Scoring………………………………………………………………………………………...7

Areal Map…………………………………………………………………………………………………………………..8

Buffer Map…………………………………………………………………………………………………………………9

Pictures……………………………………………………………………………………………………………………10

References………………………………………………………………………………………………………...........11

Angora Creek: Basic Information Sheet…………………………………………………………………...12

Hope Valley and Grass Lake Assignment…………………………………………………………………25

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Introduction:

In June of 2007 a horrific wildfire ripped through a pristine area of Lake Tahoe near

Angora Lake, Fallen Leaf Lake, Echo Lake and South Lake Tahoe. The fire started along

North Upper Truckee Road, which at the time was a densely populated area of homes. The

fire scorched over 3,000 acres and burnt down more than 200 homes, 60 commercial

structures, and damaged several other buildings in its path. Today all that remains of the

fire is a massive open area full of charred Pine trees, and shrubbery. Since the fire was in

the heart of the Lake Tahoe water shed the concern of ash and debris getting into the

hydrologic systems was a great concern for many.

One of the main hydrologic systems that were involved in the Angora Fire was

Angora Creek. The creek wound its way through the base of Angora Meadows, but was not

directly in contact of the fire. This specific location is known as a riparian wetland. Upon

first arrival, the creek looked shallow and very narrow. There were a few beaver dams that

allowed for the assumption that this location is slightly in engineered equilibrium. Due to

this assumption it can be said that this specific system has healed from this major

disturbance. Along with the observations of beaver work, new growth has well been on its

way to helping this system heal.

The majority of living vegetation that remains after the fire is primarily Jeffery Pine

and Bitterbrush. These two plant types were not the only remaining types within the area.

There were also several different types of grasses that can be found along the creek. Tufted

Hair grass was the most abundant grass type. Outside of the burn area, there were several

other types of vegetation such as; Tufted Hair grass, Purple Aster, Alder trees, Salix Lamoni,

and Carix Utricularia. With such varying plant diversity, the means for a reliable water

source is important.

Angora Creek is a long narrow creek that winds its way at the base of Angora

meadows and finds its way to the North Upper Truckee River. There are only two possible

sources of water that feed into this stream. One being annual rainfall, and the most

important source of water for Angora Creek is the Sierra Nevada snowpack. Having a

strong source of water is extremely necessary for an area like this to allow for the site to

heal itself and for new plant growth.

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Due to how well new plant growth was occurring, at first glance, the notion can be

made that the water quality of Angora Creek very is sufficient. After doing several water

tests, the thought of sufficient water quality within the creek, can be supported because of

the findings of new plants, and several microorganisms. Five tests were conducted on the

water. The five were; pH, dissolved oxygen, electric conductivity, nitrate, and phosphate.

The readings for each test are as follow: pH had a reading of 6.4, which is slightly acidic;

dissolved oxygen was 3.7 mg/L with a saturation of 33%; electric conductivity read 52.4;

nitrate was 25 ppm; and phosphate was less than 20 ppm. With these tests conducted, the

conclusion was made that Angora Creek is aligotrphic meaning that it has low nutrient

levels and a high quality of water. By having low nutrient levels in the water, the same can

be said about the soils of the region.

There are three main soils series that can be found in this area, the Tahoe Series, the

Marla Series and the Watah Series. All three of these soils are low in nutrients and they all

drain very poorly. The Tahoe Series is a deep soil primarily made up of mixed material,

mostly andesitic lahar and granodiorite. Marla Series also is a deep soil that is formed in

alluvium from primarily weathered granite rock. The Watah soils are also nutrient poor,

deep soils that are formed from organic material. The reason these soils pop up could

possible be due to the amount of carbon that found its way to the ground after the fire. By

being such a disturbed area of land, with the combination of decent soils and good quality

of water Angora Creek is a surviving system. Although it is a surviving system, it is still in

an area that can over time be exposed to several other types of disturbances.

Disturbances can vary from fire (as occurred) to human disturbances such as

mountain biking, ATV riding, camping and several other activities that can harm the

environment. Angora creek has no visual impacts of disturbances. The only noted

disturbance was with in the AA was a small electrical box that was beneath the electrical

pole. There were other possible disturbances near the AA like North Upper Truckee Road,

the several dozen homes that ran along the road, as well as the small foot/mountain biking

path that ran above the AA. None of these disturbances directly impacted Angora Creek.

Methods:

California Rapid Assessment Method or CRAM is used by field scientists to assess a

representative wetland area by using several environmental and habitual aspects. These

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aspects involve vegetation, topography and hydrology. For the Angora Creek site, Riverine

Wetlands CRAM was used, which involves four attributes. Those attributes are; Buffer and

Landscape Quality, Hydrology, Physical Structure, and lastly Biotic Structure. Once each

attribute is assessed, an alphabetical score (A-D) is given and each alphabetical score has a

corresponding numerical value where an A equals 12, B equals 9, C equals 6, and D equals

3.

Results:

Results for CRAM consist of four scores for each attribute. The scores are made up of

the four different alphabetical and numerical scores. Each attribute has a series of tests that

field scientist conduct in order to obtain a score. The results for Angora Creek attribute 1

(Buffer and Landscape context) had a score of 93.29. Attribute 2 (Hydrology) had a score of

100, attribute 3 (Physical Structure) had a score of 75 and lastly attribute 4 (Biotic

Structure) had a score of 69.43. Once each attributes score is computed, the overall AA

score is then conducted, by taking the average of the four attribute scores. The overall AA

score for Angora Creek came out to be an 84.43. (Refer to page 7)

Discussion:

Previously, the same CRAM assessment was done on Angora Creek. The results that

the instructor copy came up with were a little lower than what the latest CRAM results

showed. The overall AA score of the instructor copy was 82.0, which was only 4 points off

of the newest score that was an 86.0. The fact that these two scores are so close is

surprising because each CRAM assessment was ran during different season. The lack of

rainfall, and the continuous build up of sediment can be the primary reason as to why these

two scores are so close.

Conclusion:

Assessing Angora Creek was an excellent way to really determine how well this

location has recovered from this major disturbance. Not only was it a great tool to conclude

that Angora Creek has heeled itself from this fire, but it was helpful for me to obtain a

better understanding of how to go about conducting a CRAM. The Tahoe Region is a place

dear to my heart not only because I am an avid outdoors person, but also it is an area that I

have many memories of my childhood. To see such a beautiful landscape destroyed by a

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fire and then recover so wonderfully is a great way to open my eyes to how important a

strong understanding of natures work is.

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Riverine Wetlands Score

Attribute 1: Buffer & Landscape ContextAlpha Numeric

Stream Corridor Continuity A 12Buffer Submetric: Percent of AA with Buffer A 12

Buffer Submetric: Average Buffer Width A 12Buffer Submetric: Buffer Condition B 9

Raw Attribute Score 22.59Final Attribute Score 93.29%

Attribute 2: HydrologyAlpha Numeric

Water Source A 12Channel Stability A 12

Hydrologic Connectivity A 12

Raw Attribute Score 36Final Attribute Score 100%

Attribute 3: Physical StructureAlpha Numeric

Structural Patch Richness A 12Topographic Complexity C 6

Raw Attribute Score 18Final Attribute Score 75%

Attribute 4: Biotic StructureAlpha Numeric

Plant Community Submetric: Number of Plant Layers A 12Plant Community Submetric: Co Dominant Species C 6

Plant Community Submetric: Percent Invasive A 12

Plant Community Composition Metric 10

Horizontal Interspersion B 9Vertical Biotic Structure C 6

Raw Attribute Score 25Final Attribute Score 69.44%

OVERALL AA SCORE 84.43%

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Areal Map

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Buffer Map

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Pictures

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References

Dwire A, K., Kauffman J. B. Fire and riparian ecosystems in landscapes of the western USA.

Forest Ecology and Management. 2003. 178: 61 – 74

Tahoe Riverine CRAM Training Session Field Site #5 Thursday Morning. INSTRUCTOR

COPY

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