Study ID 255

Multi-decade. spatially explicit population studies of canopy dynamics in Michigan old-growth forests

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Realm: Terrestrial
Climate: Temperate
Biome: Temperate broadleaf and mixed forests
Central latitude: 46.366700
Central longitude: -87.133300
Duration: 10 years, from 1989 to 2007

2915 records

22 distinct species

Across the time series Acer saccharum is the most frequently occurring species

Citation(s):

Woods, K. D. (2009) Multi-decade, spatially explicit population studies of canopy dynamics in Michigan old-growth forests. Ecology, 90, 3587.

Methods

In 1935. U.S. Forest Service personnel established 246 0.2-acre (809 m2) continuous forest inventory (CFI) plots on a 2 × 5 chain (40.2 × 100.6 m) grid (2 chain spacing on north-south lines) over the entire RNA (Fig. 2). Plot centers were marked with steel pipes. Stems >5 in (12.7 cm) diameter at 1.4 m height (diameter at breast height. DBH) were tallied by species in 1-inch (2.54 cm) diameter classes for most plots (n = 236). In 1948. alternate plots along N-S lines were censused in the same manner (n = 123).In 1974–1980. under the direction of Dr. Frederick Metzger of the U.S. Forest Service. all CFI plots were recensused. with all woody stems >0.5 in (1.27 cm) DBH recorded by species and DBH to nearest 0.1 inch using Biltmore 'cruising sticks' (Frederick Metzger. personal communication). Standing dead stems > 10 in (25.4 cm) DBH and with bark intact were also recorded. but probably not consistently (see below). Data for three plots have not been relocated (n = 243). Active Forest Service research at the RNA was suspended following closure of the Forest Service Northern Hardwoods Laboratory in Marquette. MI in the early 1980s. Some species. occurring primarily as large shrubs. may not have been consistently recorded (Acer spicatum. Alnus sp. Amelanchier sp. Cornus sp. Corylus cornuta).Beginning in 1989 and continuing over the next several years. I initiated remeasurements. initially for upland plots only. For upland plots (n = 134). all woody stems > 5 cm DBH were measured to nearest 0.1 cm and mapped in polar coordinates from the plot center. Smaller stems were similarly mapped and measured in a central sub-plot 8 m in radius: in 1989 the minimum size for recording stems in the sub-plot was 3 cm; in 1992. minimum size was 2.5 cm; for all subsequent years all stems > 1 cm DBH were included. In 1989–1992. distances were measured using tapes and azimuth using Suunto site-through compasses; from 1993 onward. distances were measured using Sonin ultrasonic rangers. Subsequently. woody stems in upland plots have been remeasured and newly established stems mapped and measured at. generally. five-year intervals (three or four measurements for most); since 1999. these plots have been consolidated into two groups sampled at staggered intervals such that the most recent measurements are for 2004 and 2007. For some species of large shrubs (Acer spicatum. Corylus cornuta. Cornus rugosa) stems were tallied without mapping. All dead stems > ca. 20 cm (including down stems and stumps) were included in initial samples of upland plots. Dead stems were identified to species where possible. and rated on an 8-point decay scale (Table 1). and classed as standing. tipped up. or broken (with height of break recorded); DBH was measured or estimated for dead stems where possible (for decay codes of 7–9. diameter measurements were typically impossible). In subsequent remeasurements of upland plots. stems dying since previous measurements were similarly coded (generally using only the first two grades of the decay scale) where possible (dead smaller stems could not always be relocated); after initial plot measurements. DBH was not recorded for dead stems.Since 1994. with major efforts beginning in 2001. I have remeasured a total of 65 additional plots in wetlands on peat and muck soils. As for upland plots. all stems > 5 cm DBH were measured for the entire plot and stems from 1–5 cm for an 8-m radius sub-plot. but stems were not mapped in these stands. Dead stems were not consistently recorded. and are not included here. Remeasurements of tree stand in permanent plots Unit of abundance = IndCountInt, Unit of biomass = NA