EPOW - Ecology Picture of the Week

Sea Rise, Forest Decline

Wetland Forests, Chesapeake Bay
Maryland, USA

Explanation:  Compare the top and bottom photos.  These are both in the general vicinity of Blackwater National Wildlife Refuge, which is one corner of the amazing and expansive Chesapeake Bay along the eastern seaboard of the U.S.

What is going on here?  The top photo is of a lush woodland nestled within some pristine coastal wetlands within the Bay.  

But the bottom photo?  We may be witnessing more of the future here.  This pine forest has drowned and died back.  But why?

Ongoing research by U.S. Geological Survey and U.S. Fish and Wildlife Service is attempting to understand the dynamics of such forest change.  It appears that the culprit is not bugs, or disease, or pollution ... but rather sea level rise relative to the elevation of the land.

What causes relative sea level rise, and what its effects might be on the future of coastal wetlands and woodlands, is under investigation.  Possible factors contributing to relative sea level rise include climate change, tree root decay, post-periglacial subsidence of the land, and local variation in growth and decomposition of marsh vegetation.  

Additional factors in other locations might include oil and gas extraction that causes the land level to sink; presence of river dams that reduce the amount of sediment input to coastal lands; increase of storm surge energy, and change in frequency and intensity of storms, as caused by climate change; shifts in ocean currents caused by climate change; and increasing ocean temperature caused by global warming, which serves to increase water volume and thus coastal flooding.  

Relative sea level rise is not a simple thing to study!  Nor is it a new topic of study.  Research on this goes back at least to the 1960s.  

And as coastal forests vanish, so too could their immense ecological value and environmental services, including provision of fish habitat, recreational opportunities, protection from storm surge, provision of water quality, and contribution to the biodiversity of the ecosystem.