Cork oak forests support one of the highest levels of biodiversity among forest habitats, as well as the highest diversity of plants found anywhere in the world.
In cork oak landscapes, plant diversity can reach 135 species every square meter; many have aromatic, culinary, or medicinal value.
Cork oak landscapes contain more than 30 different brackens, some of them very rare, and cork oak microflora many species of fungus.
The fertile undergrowth is thick with heathers, leguminous plants, rock roses, and herbs.
Cork oak forests also host a rich diversity of fauna, including spiders, spadefoot toads, geckos, skinks, vipers, mongoose, wild cats, roe deer, boars, Barbary deer, and genets. Perhaps the most celebrated example, the endangered Iberian Lynx (Lynx pardinus) has recently recovered from near extinction.
Countless millions of wintering birds from northern Europe, including virtually the entire common-crane population, shelter in cork oak landscapes in the Mediterranean.
Cork oak forests are a vital haven for storks, kites, vultures, buzzards, and booted and short-toed eagles that gather at bottlenecks like the straits of Gibraltar and Messina and the Bosphorus, where they can climb in thermals and cross safely.
The trees help conserve soil by protecting against wind erosion and increasing the rate at which rainwater is absorbed.
Water erosion is also less in areas below upland forests that intercept rainfall, while reservoirs linked to irrigation and hydroelectric installations are protected from eroded soil.
Reduce Greenhouse Gasses
Cork oak landscapes store carbon, reducing greenhouse gases in the atmosphere, especially in the early years of their life when they grow fast. The Portuguese cork forest acts as a carbon sink for 4.8 million tons of CO2. The value of CO2 absorbed by this indigenous forest is estimated to be an offset of 113.2g of CO2 per cork. This makes the net carbon emission from the use of natural cork a carbon offset of -112 grams per cork.
Cork oak trees store carbon in order to regenerate their bark, and a harvested cork oak tree absorbs up to five times more than one that is not. (WWF)
Depending on the growing region, cork trees are harvested every nine to twelve years. The trees are not cut down and can be expected to live for 200 years. This makes the industry a near-perfect example of renewable production.
Most modern wine cork factories utilize cork dust from the processing plant to co-generate electricity. Larger scraps are reserved for use in agglomerated cork production. Virtually every piece of the wood harvested is utilized. Solid waste is minimal.
The process is repeated every decade for the life of the tree. Harvested trees normally live past 200 years. They are generally considered to be more healthy than those trees that have never been harvested.
Natural wine corks consist of wood and a thin coating of silicon/paraffin (for better extraction from the bottle).
Used corks have long been collected for craft purposes to make wreaths, coasters, and in one famous case - a full size sailing ship that traveled Portugal's Duoro River. They are also popular with suppliers of specialty ground covers (playgrounds) and can used in mulch and soil conditioners.
Until recently, there was little opportunity to return the wine corks to a manufacturer for recycling into second generation cork products. The reason was primarily geographic as the vast majority of cork manufacturing plants were in Europe.
This has now changed with the advent of several recycling program in North America. Two of the fastest growing have opened numerous receiving facilities in the U.S. They arrange for delivery to industrial cork facilities, where the wine corks are ground into small pieces for reassembly into cork sheets suitable for flooring, gaskets and a growing list of new products.