Yale Study Finds Evidence that Damaged Ecosystems Can Recover Rapidly

Yale Study Finds Evidence that Damaged Ecosystems Can Recover Rapidly

Editor

Environmental News Network

May 28, 2009

http://www.enn.com/ecosystems/article/39985

 

A recent study by Yale University's School of Forestry

and Environmental Studies reports that if humans commit

to the restoration effort, most ecosystems can recover

from very major disruption within decades to half-

centuries. The study was written by Holly P. Jones and

Oswald J. Schmitz and will appear in the June edition of

the journal PLoS ONE. According to the study,

researchers compiled information from 240 independent

studies conducted since 1910 that examined large, human-

scale ecosystems recovery following the termination of

both human and naturally imposed disruption.

 

Researchers grouped the data into seven broad aquatic

and terrestrial types of ecosystems, and disruptions

such as deforestation, hurricane, invasive species, oil

spoils, power plant and sea trawling. Most of the

studies measured multiple response variables, which

researched grouped into three categories: ecosystem

function, animal community, and plant community. The

researchers evaluated the recovery of each of the

variables in terms of the time it took for them to

return to their original state as determined by each

study's author. The study also assessed whether recovery

times were related to the magnitude of the disturbance.

 

Reportedly, 83 studies demonstrated recovery for all

variables; 90 demonstrated a mixture of recovered and

non-recovered variables; 67 demonstrated no recovery for

any variable; and 15 percent of all the ecosystems in

the analysis are beyond recovery. The average recovery

time was 20 years or less, and reportedly did not exceed

more than 56 years. It was found that recovery from

human disturbances was slower than natural disturbances,

such as hurricanes. Recovery following agricultural,

logging, and multiple stressors was significantly slower

than all of other disturbance types.

 

The results of the study showed a positive relationship

between the degree of disturbance and the recovery time.

However, this was entirely determined by the type of

ecosystem. For instance, the study states that aquatic

system recovered much faster than terrestrial.

Researchers noted that aquatic systems may recover more

quickly because species and organisms that inhabit them

turn over more rapidly. For instance, forests took the

longest to recover due to the fact that forest

inhabitants take longer to regenerate after logging or

clear-cutting.

 

One potential pitfall of the study is that the

uncertainty of the systems original state. The study

explains that major disturbances such mass extinction

combined with lower level disturbances such as pollution

or climate change could create a baseline far removed

from the historical natural state.

 

Jones and Schmitz concluded that "recovery is possible

and can be rapid for many ecosystems, giving much hope

for humankind to transition to sustainable management of

global ecosystems."

 

To view the research article by Jones and Schmitz, visit:

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0005653