Swamp milkweed at Allens Pond Wildlife Sanctuary
Swamp milkweed at Allens Pond Wildlife Sanctuary

Intensive sampling of vegetation on Mass Audubon wildlife sanctuaries began in the 1980s and continues to this day.

Plant Lists 

As of April 2011, we have plant species lists for 82 out of 97 properties; 68 have lists that we have catalogued as “good”, 14 as “fair”, and 2 as “poor.” The properties listed as “good” encompass over 23,500 acres, roughly 90 percent of Mass Audubon’s land holdings.

Five wildlife sanctuaries contain over 500 plant species, as indicated by the largest green triangles in the map below. The two highest counts are for Broadmoor in Natick and Pleasant Valley in Lenox, with 655 and 645 species respectively.

A high-species richness (number of species) is a function of diligent sampling plus a diversity of habitats and rich soils rather than any geographic trends from north to south or east to west. Broadmoor contains different types of wetland, a variety of successional communities (fields and shrubland) plus forest. The wildlife sanctuary was recently intensively sampled over a two year period by Lisa Standley, an expert botanist and member of the sanctuary committee. Pleasant Valley is in an area known for its rich soils and high plant diversity. 

Plant species richness recorded at Mass Audubon wildlife sanctuaries 

The size of the triangle indicates the number of species, as shown in the legend. 

Map 1

Floral Statistics 

Based on information up to 2010, Mass Audubon wildlife sanctuaries contain slightly more than half the number of species that have been recorded in Massachusetts (1,614 of 2,814 species). When non-native species are removed, the percentage is much higher, about 76 percent (1,172 of 1,638 native species). We have recorded 91 of the 303 state-listed (endangered, threatened or special concern) species.

Quantitative Vegetation sampling 

We have resurveyed a total of 32 vegetation plots on seven wildlife sanctuaries since 2004. These include 20 plots on six wildlife sanctuaries (Moose Hill, Wellfleet Bay, Sesachacha Heathlands, Felix Neck, Wachusett Meadow, and Flat Rock). These plots had been sampled previously in the 1980s and 1990s.

We have also set up and sampled new vegetation plots: 13 new plots were sampled at Rutland Brook and 12 at Laughing Brook. Additional plots have been sampled at Daniel Webster, Allens Pond, Skunknett River, and Sesachacha Heathlands as part of our evaluation of ecological management projects.

Try Island at Wellfleet Bay Wildlife Sanctuary

An example of where we have compared past and present vegetation using our permanent plots is at Try Island on Wellfleet Bay Wildlife Sanctuary. The management goal for Try Island is to maintain an uncommon tree community dominated by mockernut hickory (Carya tomentosa).  Our measurements of different tree species indicate that this species is maintaining itself over the 20-year period. This suggests that we do not need to institute direct management measures to maintain the targeted natural community at this point in time.

Differences in vegetation structure at Try Island, Wellfleet Bay Wildlife Sanctuary. This plot was first sampled in 1985 and then resampled in 2004. Note the increase in trees and shrubs and the decline in grasses (graminoids). 

Chart 2
Chart 1