Should I boycott cypress mulch?
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It’s hard to think of mulch as a controversial topic, but as with most
things these days, we find people on both sides of an issue. As with
most things these days, some of the opinions are based on substance,
others are not. In the southern United States, some environmental groups
are advocating a boycott of cypress mulch. Cypress mulch is derived
from baldcypress and pond cypress, which grow in ecologically sensitive
wetlands in the Southeast. Cypress wood is highly valued for is natural
decay resistance. Florida and Louisiana are the leading states for
cypress harvesting for timber and other products. In Louisiana, it is
unclear if cypress is logged solely for mulch, but cypress harvesting
for mulch does occur in Florida. According to Dr. Jim Chambers,
professor of Forestry at Louisiana State University and chair of a
governor’s science panel on forested wetlands in Louisiana, cypress
mulch production is a sensitive issue.
“Many of our cypress-tupelo forests are in a severe state of decline.
As you can imagine, these forests are very important to south Louisiana
for many reasons. Areas permanently flooded, areas that are flooded for
substantial parts of the growing season and areas subjected to salt
water input, cannot regenerate. The amount of forested areas with these
conditions continues to increase as subsidence increases, coastal
wetlands are eroded by storms, and human impacts on hydrology continue
to degrade many sites.”
The inability to regenerate new stands of cypress is an important
concern and calls into question the sustainability of cypress harvesting
on these sites. Chambers is working with environmental groups and
others to develop a process to certify that mulch is produced from
sustainable forest harvest operations.
Another issue related to cypress mulch, is a claim that is circulating
in parts of Michigan (and perhaps elsewhere) that cypress mulch is
linked to cancer. I conducted a search of the National Library of
Medicine and National Institutes of Health literature database (www.pubmed.gov) on cypress and cancer. The only hits I found were related to studies looking at falsecypress (Chamacyparis)
extracts for anti-cancer properties, similar to taxol. The claims of
cypress mulch and cancer may be an amalgam of the environmental concerns
over cypress harvesting discussed above, and concerns over use of mulch
derived from CCA (chromated copper arsenate) treated wood, which is
used for decking and other uses similar to cypress. Research has shown
that leachate from mulch containing CCA treated wood can have elevated
levels of arsenic and metals above established health standards.
