Taxonomy and Ecology Of Inland Sand Dune ... - Mycorrhizae

23annually, a mean annual temperature 3˚C, and an annual precipitation of 363mm. He also estimated that the annualprecipitation increased to 762 mm at thesand dune field.Figure 1 Outline of study area, NorthPark, and Jackson County in NorthernColorado.Map is modified from Ahlbrandt andAndrews (1978).During the summer, the active NorthPark sand dunes are disturbed by peopledriving dune buggies or dirt bikes acrossthe dunes. This disturbance reduces orkills the vegetation near the edges of theactive dunes.II. SAMPLE COLLECTIONNorth Park sand dune plants weresampled for biological, taxonomical, andecological studies of VAM fungi. Majorplant species were sampled randomlyduring 1987 for mycorrhizal associationsand for plant and VAM fungalidentification. In 1988 three soil profileswere established around individualOryzopsis hymenoides stands tocorrelate the initial soil depth, moisture,and pH with the ability of the soil tosupport VAM colonization in a bioassayplant (maize). Also in 1988, sandsamples were collected around plant rootsystems and from nonvegetated areas(active sand dunes) along three transectsto correlate the effects of vegetation onVAM colonization in bioassay plants.Vegetation data (number of species andpercent cover) in each quadrat werecollected to correlate species number,cover, and frequency with the ability ofthe soil to support VAM colonization.Additional collections were made todetermine soil physical characteristics.