Forest Vegetation Strongly Related to the Earthworm Biomass

Vegetation and earthworm biomass scatterplot.

I investigated the relationship between vegetation and introduced earthworms on the property.  Several important relationships were observed.  Herbaceous vegetation data was collected at 25 randomly selected points on the property within one square meter quadrats.  Native vegetation including tree seedlings in the herbacous layer were negatively correlated with the amount of earthworms in the soil.  Invasive plants were positively correlated with earthworm biomass.  The relative strength of each of these relationships varied.  Invasive plants and  total native plants were the strongests correlations, while native tree seedlings were not as strong.  Tree seedling cover can be influenced by several factors including herbivory, seed production, acid precipitation, as well as many other disturbances.  Neverthess, this data suggests that introduced earthworms are one more important factor that influences our forest ecosystems.

Earthworm Species Inventory and Forest Cover Type Associations

A totalof the 14 earthworm species were detected during the 2014 survey at White Memorial Foundation.  We randomly selected 82 plots throughout the property and collected 993 specimens.  Juvenile or non-clitellate individuals for Megascolecidae family and certain Lumbricid genus are impossible to identify to species using external and internal characters with currently developed keys.  Some cover types were sampled more than others, nevertheless random sampling insured that the frequency distribution reflects the actual proportion of cover type at White Memorial.  The native species Eisenoides lonnbergi was found in only two cover types, oak and mixed conifer, specifically in plots located near wetlands.  The remaining species have exotic origins and were detected in many cover types.  Intially, it appears that the hardwood cover types more species of earthworms than the conifer stands.  Conifer stands tend to have lower soil pH than hardwood cover types, which could influence the species that inhabit the stands.

Ashes to ashes Republican American

White Memorial Conservation Center research director James Fischer measures
the girth of a century-old white ash tree on the preserve.  Ash trees across
the state are in danger from the emerald ash borer.
Photo by Kathryn Boughton, Republican-American.

Ashes to ashes Republican American

White Memorial's Emerald Ash Borer Surveillance program was mentioned in this article on January 3, 2015 in the Republican American.

Earthworm Biomass vs. soil pH by Cover Type

Ave. Earthworm Biomass vs. Ave. Soil pH by Forest Cover Type at White Memorial in 2014.

The strength of relationship was explored between soil pH and introduced earthworm biomass by forest cover type.  As previously posted, the overall relationship is significantly positively correlated. All of the relationships by cover types were positive and contributed to the overall association. The strongest relationships was observed in the mixed conifer and mixed hardwoods.  The lack of significant differences within each forest cover was likely due to small sample sizes.  Although the strength of the relationship between soil pH and earthworm biomass was not significant, northern hardwood forests had greater earthworm biomass and soil pH.  Northern hardwood tree species leaf litter increases the O-horizon pH significantly and this could favor introduced earthworms.

Monarch Butterfly Moves Toward Endangered Species Act Protection

Monarch Butterfly (Danaus plexippus) is migratory species that can travel from Canada to Mexico and is currently being reviewed by the US FWS as a species to be protected by the US Endangered Species Act. 

Monarch Butterfly Moves Toward Endangered Species Act Protection

US Fish and Wildlife Service reviews the request to list the Monarch Butterfly (Danaus plexippus) as an endangered species by several conservation groups and scientists.  North American populations have suffered severe loss over the past decade due to habitat loss, pesticide application, severe weather patterns, as well as many other factors.