Ecological Applications, 8(4), 1998, pp

نویسنده

  • HARTWELL H. WELSH
چکیده

Road construction of the Redwood National Park highway bypass resulted in a large accidental infusion of fine sediments into pristine streams in Prairie Creek State Park, California, during an October 1989 storm event. This incident provided a natural experiment where we could measure, compare, and evaluate native stream amphibian densities as indicators of stream ecosystem stress. We employed a habitat-based, stratified sampling design to assess the impacts of these sediments on the densities of aquatic amphibians in five impacted streams by comparing them with densities in five adjacent, unimpacted (control) streams. Three species were sampled in numbers sufficient to be informative: tailed frogs (Ascaphus truei, larvae), Pacific giant salamanders (Dicamptodon tenebrosus, paedomorphs and larvae), and southern torrent salamanders (Rhyacotriton variegatus, adults and larvae). Densities of amphibians were significantly lower in the streams impacted by sediment. While sediment effects were species specific, reflecting differential use of stream microhabitats, the shared vulnerability of these species to infusions of fine sediments is probably the result of their common reliance on interstitial spaces in the streambed matrix for critical life requisites, such as cover and foraging. Many streamdwelling amphibians are highly philopatric and long-lived, and they exist in relatively stable populations. These attributes make them more tractable and reliable indicators of potential biotic diversity in stream ecosystems than anadromous fish or macroinvertebrates, and their relative abundance can be a useful indicator of stream condition.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Metabolic and productive responses of dairy cows to increased ion supplementation at early lactation in warm weather.

We found previously that the current recommendations for Na+, K+, and Cl- contents in the diet do not meet the needs of lactating cows. The response of cows receiving a ration with increased amounts of Na+, K+, and Cl- (E cows) were compared with those of cows consuming the same ration with a fixed concentration of these ions (C cows) between weeks 2 and 8 post partum (PP). Milk, protein, fat a...

متن کامل

Wireless-adaptive fair scheduling for multimedia stream - Electronics Letters

I MOHAMMED.A.F, and L A S L D.: 'High resolution techniques for Loran-C skywavedelayc?timation', Elecrmn. Len., 1999.35, (18J,pp. 1516-1517 2 MOHAMMFII.A.F., and LAST, J.D.: 'Loran-C skywave delay drtcction using ARMA algorithm', Eleefmn. Le//., 1998, 34, (17). pp. 16561655 3 MOHAMMED. A F . , and LAST, 111: 'Loran-C skywave delay estimation using the AR algorithm', Eleceon. Len, 1998, 34, (23)...

متن کامل

Extraction of noise parameters of transistor using a spectrum analyser and 50/spl Omega/ noise figur - Electronics Letters

‘Second harmonic power generation from GaAs-IMPATT diodes at 210GHz’, Int. J. Infrared Millim. Wuves, 1998, 19, (4), pp. 587593 EISELE, H.: ‘Efficient second-harmonic power extraction from GaAs TUNNETT diodes above 200GHz’, Electron. Lett., 1998, 34, (13), pp. 1324-1326 LIEBIG, D., and SCHUNEMANN, K.: ‘Cellular automaton particle simulation and sensitivity analysis of GaAs-MITATT-diodes for ope...

متن کامل

Representation of second-order polarisation mode dispersion - Electronics Letters

1 MARSHALL, G.F.: ‘Optical scanning’ (Marcel Dekker Inc., New York, 1991) 2 PODOLEANU, A.GH., and JACKSON, D.A.: ‘Combined optical interference tomograph and scanning laser opthalmoscope’, Electron. Lett., 1998, 34, pp. 1088-1090 3 DICKENSHEETS, D.L., and KINO, G.s.: ‘Silicon-micromachined scanning confocal optical microscope’, J. Microelectromech. Syst., 1998, 7, pp. 3847 4 POLE, R.v., WERLICH...

متن کامل

(12) United States Patent

ions," Proceedings of the CHI '98 Conference on Human Factors in Computing Systems (Los Angeles, CA, Apr. 1998), pp. 171-178 (1998). Christel et al. "Information Visualization within a Digital Video Library," Journal of Intelligent Information Systems 11 :235-257 (1998). Dellaert et al. "Recognizing emotion in speech," Proceedings ICSLP 96. Fourth International Conference on Spoken Language Pro...

متن کامل

Rewriting logic: roadmap and bibliography

Data Types Joint with the 5th COMPASS Workshop, S. Margherita, Italy, May 30–June 3, 1994, Selected Papers, Lecture Notes in Computer Science, Vol. 906, Springer, Berlin, 1995, pp. 351–367. [201] M. Leucker, T. Noll, Rewriting logic as a framework for generic veri9cation tools, in: K. Futatsugi (Ed.), Proc. 3rd Internat. Workshop on Rewriting Logic and its Applications, WRLA 2000, Kanazawa, Jap...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2001