• Category
  • Length Range
    13-21 µm
  • Width Range
    3.3-4.2 µm
  • Striae in 10 µm
    23-25

Identification

Description

Valves are linear to lanceolate, with bluntly rounded to somewhat rostrate apices. Fibulae are distinct and number 11-14 in 10 µm. The fibulae are equidistant and the central nodule absent. Areolae are indistinct.

Autecology

Nitzschia alpina is widely distributed in lakes and streams in the Northern Rocky Mountains, where mean pH is 7.8 and mean specific conductance is 266 µS/cm. The most common diatom associates of N. alpina in these waters are Fragilaria tenera, Cyclotella comensis, Brachysira microcephala, Encyonopsis cesatii, Nitzschia angustata and Nitzschia bryophila. Lange-Bertalot (1980) reports this species from Iceland and from "unpolluted peatwaters" in Germany and elsewhere.

Bowman  Lake 2
Credit: Loren Bahls
Bowman Lake, Glacier National Park, Montana: home of Nitzschia alpina.

Original Description

  • Author
    Hust. 1943

Original Images

Nitzschia Alpina  Ill
Nitzschia Alpina  Descr

EMAP Assessment

EMAP Distribution

Nitzschia Alpina  Hustedt 3
Map 3

Response Plots

Nitzschia Alpina  Hustedt

Cite This Page

Bahls, L. (2012). Nitzschia alpina. In Diatoms of North America. Retrieved July 21, 2018, from https://diatoms.org/species/nitzschia_alpina

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Nitzschia alpina from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)
STRAHLER = distribution plot of the Strahler Stream Order
SLOPE = stream reach gradient (degrees)
W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.
PHSTVL = pH measured in a sealed syringe sample (pH units)
log_COND = log concentration of specific conductivity (µS/cm)
log_PTL = log concentration of total phosphorus (µg/L)
log_NO3 = log concentration of nitrate (µeq/L)
log_DOC = log concentration of dissolved organic carbon (mg/L)
log_SIO2 = log concentration of silicon (mg/L)
log_NA = log concentration of sodium (µeq/L)
log_HCO3 = log concentration of the bicarbonate ion (µeq/L)
EMBED = percent of the stream substrate that is embedded by sand and fine sediment
log_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).
DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.