By Rachel A. Simpson
Evans Old Field and Data Collection
This database contains data collected by Dr. Francis C. Evans of the University of Michigan during a 50-year (1948-1997) study of successional changes in a 7.7 ha abandoned field at the Edwin S. George Reserve, Livingston County, Michigan. For descriptions of the field, called Evans Old Field, and its flora and fauna, consult papers by Evans (1975, 1986).
The area surveyed was on a grid 180 yds by 320 yds. Trips to the area were made at intervals over the flowering season. On each trip, the phenological state of plants, particularly those in flower, was noted. In addition, locations of plants on the grid were noted. Abundances, based on visual assessments, were also sometimes noted. Over the course of each year, a list of plant species present was made. In addition, plant abundances were quantified in four surveys made approximately 10 years apart. Dates and the number of 1-sq.-yd. quadrats surveyed are listed below:
- 1953 June 25-July 2 (200)
- 1964 July 20-21 (200)
- 1974 July 10-12 (100)
- 1981 July 29-31 (200)
The Computer Database
The computer database contains phenological and presence/absence data for the old field plants. In addition results from the 4 plant surveys is included. Some information contained in the field notes is not included in the computer database. Data on fungi, lichens, and bryophytes are not included. Plant species which appeared for a short time period and which were consequently not positively identified are excluded. Species which were not on the grid are excluded as well. Information about the location of plants on the field is not included. Finally, information about the abundance of species is generally not included, except early in the plant’s history on the field or when the plant is rare on the field. For more information about abundances, etc., the field notes themselves should be consulted. These are housed in the Museums of Zoology, University of Michigan.
Because the field is undergoing succession, some areas at the edge of the grid have become the edges of woodlands. Therefore some species atypical of mid-successional fields appear in the database (e.g., Anemonella thalictroides, Hepatica americana, Viola sororia).
Following is a brief description of the information included in each category of the computer database (called `evansplts’). A second, smaller, database (called evanspltslist) consists of a list of species and their origins, growth forms, and life histories. Both of these databases are available either as Excel (version 5.0 Mac or 7.0 Win95) or as Filemaker Pro (version 3.0, Mac or Win) files.
Record: Record is the line number in the database. When the data are sorted by record, the order of the data corresponds to the order of the data in the original field notes.
Origin: i (introduced); n (native)
Growth form (G. F.): g (graminoid); h (herbaceous); s (shrub); t (tree)
Life history (L. H.): a (annual); b (biennial); p (perennial). Shrubs, trees, and vines are not assigned a life history category.
Family, Scientific Name, Author, Subspecies/Variety follow Voss (1972, 1985, 1996).
Presence: An `X’ indicates that the species was confirmed or can be assumed to have been present. In all cases, a description of the plant’s status is provided.
Buds and Buds-Notes: An `X’ indicates that buds of the species were noted on that date. Notes regarding flower buds can be used to narrow flowering dates. However, a blank cell should not be taken to mean that there were not buds. For example, once plants began flowering, the presence of buds was generally not noted.
Flowering (Fl.): Whenever any flowers were noted, the plant is categorized as in flower, indicated by an `X.’ Flowering in the Poaceae and Cyperaceae can be difficult to ascertain without close examination, and therefore dates should be taken as approximate.
Flowering-Notes: An estimate of the number of flowers is included only if it appears in the field notes to be a field-wide estimate.
Fruit and Fruit-Notes: Plants with mature fruit are indicated by an `X.’ Maturity status, when noted, is included in Fruit-Notes. If fruits were noted as `immature,’ then the plant is not categorized as fruiting. If the maturity status of fruits was not noted in the field notes, then the plant was assumed to have mature fruit.
Vegetation-Notes: This column contains selected notes on vegetation. For complete information, the original field notes should be consulted.
Survey: number of quadrats in which the species was found/number of quadrats surveyed. This data was collected during 4 surveys (see above).
Notes on Abundance: Includes data primarily for species early in their establishment or when a species is rare.
Other Notes: Information that does not fit into other categories is included here.
Dominant?: An `X’ indicates that the plant was a conspicuous and widespread flowering plant on that date.
Dominance-Notes: If more than one plant was a dominant, this information is included here.
The following abbreviations are used in the database:
|obs. = observed||w/in=within|
DATASETS TO DOWNLOAD
These files are compressed with Aladdin’s Stuffit.
Unstuffit is available free.
NOTE: The datasets described here are the property of the University of Michigan Museum of Zoology. The data may not be sold or exchanged by any other party unless given written permission by the Director of the E.S. George Reserve or the Director of the Museum of Zoology. The University of Michigan Museum of Zoology retains all rights to the data and its use.
Evans, F. C. 1975. The natural history of a Michigan field. Pp. 27-51 in M. K. Wali, editor. Prairie: a multiple view. Univ. North Dakota Press, Grand Forks, ND.
Evans, F. C. 1986. Bee-flower interactions on an old field in southeastern Michigan. Pp. 103-109 in G. K. Clambey and R. H. Pemble, editors. The prairie: past, present and future. Proceedings of the North American Prairie Conference. Tri-College University Center for Environmental Studies, Fargo, ND.
Voss, E. G. 1972. Michigan Flora. Part I. Cranbook Institute of Science Bulletin 55 and University of Michigan Herbarium. Bloomfield Hills, MI.
Voss, E. G. 1985. Michigan Flora. Part II. Cranbook Institute of Science Bulletin 59 and University of Michigan Herbarium. Ann Arbor, MI.
Voss, E. G. 1996. Michigan Flora. Part III. Cranbook Institute of Science Bulletin 61 and University of Michigan Herbarium. Ann Arbor, MI.