Population (Plants)

Forest tree, woody debris, and soil inventory data from long-term research plots at the University of Michigan Biological Station


Disturbances to forests, such as logging or wildfires, typically lead to large losses of carbon and nutrients from both the plants and soils of the ecosystem. Virtually all forests are in some state of recovery from such disturbances, whether caused naturally or by humans. Knowledge of the time required for a forest to recover its original amounts of carbon and nutrients after a disturbance is not complete, nor is an understanding of how regrowing plants, recovering soils and the year to year variation in climate interact to control recovery as a forest ages. This project takes advantage of long existing research plots in forests at the University of Michigan Biological Station to figure out how changes in forest structure, carbon and nitrogen contents of the forests, and variations in climate act together through time to influence how fast trees grow, nitrogen is retained, and carbon is captured and stored in forests. Scientists and students will make regular measurements of the types of trees, their stem sizes and mass, their patterns of leaf arrangement, the amounts of carbon and nitrogen in soils, and other factors in five forest that were cut and burned in 1936, 1948, 1954, 1980, and 1998 and so today range from 15 years to 115 years old. Several nearby much older forests will also be sampled. This will let the project link disturbances, climate and ecology for forests that are broadly representative of those across the northern United States, Canada, Europe and Asia.

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Researchers used dbh tapes and / or calipers to measure the diameter at breast height (dbh, 1.37 above ground) of every tree within the boundaries of each plot. For some plots, the location (azimuth and distance) from plot center (or corner post) was determined. For some plots, dbh values were assigned as classes (e.g., 6-8 cm dbh) and the number of stems of each species within each diameter class was recorded.

Below are the two equations used to estimate aboveground biomass and height of trees. See the Allometric_equations.csv file for constants used in these two equations according to species. In cases where the species is not listed in the table, the generic constants were used.

AG biomass = a * dbh^b * height^c
height = a*dbh^b

Data sources: 
LTREB Above Ground Biomass
LTREB Saplings Inventory 2014
LTREB Coarse Woody Debris
LTREB Allometric Equations

The effects of Typha x glauca density on biodiversity, habitat complexity, and water quality of Great Lakes wetlands


Great Lakes wetlands are being directly affected by climate change. As temperature, precipitation, and evaporation increase throughout the region, lake levels are likely to experience greater fluctuations. These fluctuations result in an increased susceptibility to invasive species. One invasive cattail, Typha X glauca, has a wide range of tolerance to water level fluctuations allowing it to establish and persist. The objectives of this research were to study if increasing T. X glauca density from channel to interior of marshes affects the abundance and species diversity of larval fish and amphibians, and macroinvertebrates, and if so, whether habitat complexity and chlorophyll a levels differed across increasing T. X glauca densities. Additionally, the directionality of the trap was recorded to test whether there was significant movement in and out of the channel. In order to study the effects of density on biodiversity, habitat complexity, and water quality of northern Michigan wetlands, larval fish and amphibians, and macroinvertebrates were sampled with light traps from June to August 2017. In addition, habitat complexity, chlorophyll a concentrations, and water quality measurements were obtained. The study indicated that average abundance of taxa decreased across increasing densities whereas species and family diversity was highest where density was highest. Differences between study sites and sampling times as well as habitat complexity contributed to these findings.


Objectives were to measure plant growth form diversity, chlorophyll a, and macroinvertebrate, amphibian, and fish diversity and abundance with increasing Typha density.

Sturgeon Bay Plant Pollinator Network Data 2017

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A short term study to assess two methods of data collection of pollinator-plant networks. It was found that data collected on a smaller number of plots throughout the season yielded very results as data collected from a larger number of plots that were only sampled once in a season. Additionally, the critical role of Pitcher's thistle (Cirsium pitchei) on the dune ecosystem was reaffirmed by both methods.


Pollinators were monitored at Sturgeon bay in Wilderness State Park. A 5000 m2 area was selected in the central part of the Sturgeon Bay dune ecosystem for sampling. The 5000 m2 area was split into a grid of 10m x 10m subplots, resulting in 50 subplots. The four corners of the plot are as follows from the northwestern corner in clockwise order: 45°43'16.2"N 84°56'25.7"W, 45°43'16.0"N 84°56'23.2"W, 45°43'12.8"N 84°56'24.3"W, and 45°43'12.8"N 84°56'24.3"W. 6 of these plots were randomly selected to be plots that would be revisited throughout the summer, while the rest were visited only once in a randomly generated order. Data collection days for RP and OTP were alternated throughout the summer.
All flowering plants in a plot were observed for a 10 minutes. Any pollinator that landed on a flower head during this interval was tallied as a pollinator visit. If a pollinator landed, left and returned, this was counted as two visits. Pollinator data was collected from 10am to 3pm throughout the summer.