Cause for hope: Secondary tropical forests put on weight fast

[Judi Lynn]

Public Release: 3-Feb-2016

Cause for hope: Secondary tropical forests put on weight fast

Smithsonian Tropical Research Institute

How fast tropical forests recover after deforestation has major consequences for climate change mitigation. A team including Smithsonian scientists discovered that some secondary tropical forests recover biomass quickly: half of the forests in the study attained 90 percent of old-growth forest levels in 66 years or less. Conservation planners can use their resulting biomass-recovery map for Latin America to prioritize conservation efforts.

"Regenerating secondary forests could play a critical role in carbon sequestration and climate change mitigation" said Daisy Dent, a research associate at the Smithsonian Tropical Research Institute (STRI) in Panama and a lecturer at the University of Stirling. "However, previous studies have tended to focus on single sites. This study brings together data from many sites that span the Neotropics. We illustrate that secondary forests are highly productive and resilient."

Less than half of the world's tropical forests are primary or old-growth forests; the rest are growing back after logging or other disturbances. The new study focused on secondary forests growing back on land almost completely deforested for agriculture. Although such forests are known to accumulate carbon rapidly, how quickly they recover and restore the ecosystem services provided by old-growth forest was uncertain because of inconsistencies in the methods used in previous studies.

This study was unprecedented in scope: 45 sites in eight countries, 1,478 study plots and more than 168,000 trees. Sites covered the full latitudinal range of the tropics, from 20 degrees north in Mexico to 22 degrees south in Brazil, and extended across areas of high-to-low rainfall and low-to-high soil fertility. The extent of forest cover in the surrounding landscape (indicating the availability of tree seeds for regeneration) and the intensity of prior land use was also considered.

More:
http://www.eurekalert.org/pub_releases/2016-02/stri-cfh020316.php

[sue4e3]

1. I just got done reading this earlier on phys.org it was nice to read

I didn't bother posting it here because it would just get annihilated

[happyslug]

2. This is about right, Pennsylvania was mostly cleared cut by 1900, and is now mostly forests.

In fact over the last 20 to 30 years deer hunters have been complaining, the Forest has shifted from Second growth to mature forests and deer are NOT a mature forest creature, it likes second growth. Turkeys are the main animal in mature forests (along with Squirrels).

Thus to took about 60 years to return to mature forests. Now these new mature forests are NOT as tall as the trees in Cook Forest State Park (one of the few virgin forests in Pennsylvania, it is the result of two large forest owners NOT knowing where their border was so neither one cut any of those trees, then Governor Pinchot, Governor of Pennsylvania in the 1920s, managed to arrange for the state to buy it, through technically was purchased by the Republican Governor of PA between Pinchots two terms as Governor).

http://www.dcnr.state.pa.us/stateparks/findapark/cookforest/

https://en.wikipedia.org/wiki/Cook_Forest_State_Park

https://en.wikipedia.org/wiki/Gifford_Pinchot

Now, Pennsylvania has been harvesting these forests over the last 20 to 30 years, but has refused to permit clear cutting on most (but not all) of the recovered forests (The Game Commission permits the most clear cutting, for it opens up lands to small game, but then over the years the clear cuts turn into secondary forests that deer like and then mature forests. Game Commission Clear cuts are known NOT to be that extensive, for most small game do NOT need a large clear area AND the native animals to Pennsylvania generally like Cleared areas next to forests, so the Game Commission makes sure both types of land exists on their lands.

Allegheny National Forest is also being logged, and it is the only profitable logging operation run by the Forest Service (all of the rest of the National Forests, the Forest Service has to build roads with tax payer's money, but the Cherry in Allegheny Forest is extremely valuable. One story I read was German furniture makers pay a premium for Cherry out of that National Forest and get picky as to the township the tree is from. Again it was mostly clear cut by 1900 but starting in the 1960s it had recovered.

The second set of land undergoing maturity are former farms abandoned in the 1930s. These were homes to people who worked on larger farms, but with mechanization of farming those jobs disappeared and they had to abandon their marginal farm to find work in the cities. Most of these farms were just self sufficient farms, crops were planned for family use but not for resale. Most were NOT even worth being purchased by larger farms for farming when they were abandoned, required to much manual labor to farm. These were abandoned mostly in the 1930s and into the 1950s as the people on those marginal farms moved to the cities. These farms returned to scrub then secondary growth and now 60 to 70 years later becoming mature forests. Most trees on such farms tend to grow faster then on the hillsides of Western Pennsylvania but still take 60-to 40 years to mature, and when it comes to timber them, most timbering takes place when they are 80 to 100 years old. Thus the clear cut woods of 1900 are being re timbered today, these abandoned farmlands are next.