What do trees do for us?

Trees beautify our surroundings, absorb noise and dust, provide shelter and food to humans, animals, birds and insects, absorb carbon dioxide and produce oxygen, prevent erosion...what don't trees do for us?


Carbon Sequestration in Israel’s Forests

The accumulation of greenhouse gases in the atmosphere is a matter of concern for all of humanity.  There is an international effort to reduce carbon dioxide emissions, but there is one process that actually works in the reverse direction (along with carbon sequestration by the oceans) – the process of photosynthesis in trees that stores carbon while releasing oxygen into the atmosphere.

A long-term study of Yatir Forest carried out by Prof. Dan Yakir and his team from the Weizmann Institute of Science has provided surprising results.  It turns out that this KKL-JNF coniferous forest on the edge of the desert, which grows in extreme climate conditions, sequesters oxygen to the same degree as European forests.
Data on the Yatir Forest:
The trees in Yatir Forest reach an average height of 10 meters, the density is approximately 30 trees per dunam (quarter acre), while the precipitation consists of an average of only 285 mm. of rainfall per year.

The forest’s productivity in terms of carbon sequestration:
  • About 230 kg of carbon per quarter acre per year (i.e. about 7.7 kg. of carbon per tree per year).
  • Over a period of 70–100 years, (which is the estimated life extent of deciduous trees) each tree stores around 500–800 kg of carbon.
In comparison, pine forests in Europe sequester 200 kg of carbon per quarter acre each year.  The average sequestration of most pine forests in the world is 250 kg of carbon per quarter acre per year.
How does the Yatir Forest function so well and sequester carbon in its hot, dry conditions?
  • The trees use less energy for respiration than is needed for photosynthesis.
  • Its biological activity (carbon sequestration) starts early in the spring, enabling a long activity season, similar to European forests.
These factors lead to higher efficiency in the carbon utilization process.

Also worth noting:
Side by side with the Yatir Forest’s surprising efficiency in carbon sequestration, its dark foliage causes it to become somewhat hotter than its paler edge-of-the desert environment. Although this warming process works in the opposite direction, it does not negate the high degree of carbon sequestration.

At the present time, KKL-JNF and the researchers are preparing to expand their research and measurements to forests in the Mediterranean regions of Israel.

Economics-based research studies have shown that in Israel’s high-density, urban environment, the forest’s recreation value, when calculated in a cautious manner that only takes into account the price that residents need to pay for a forest, not only covers the cost of establishing and tending the forest over the years, but pays itself back many times over.  Obviously, this profit does not appear in any official cash flow record, but it is expressed in the forest’s social value when it is enjoyed by all who visit it.

One tree...

  • One tree can be home for scores of birds over the course of the decades of its life.
  • One tree near a house is like an acoustic wall, inhibiting noise considerably.
  • One tree helps lower the temperature in its vicinity, up to four degrees on summer days.
  • Planting trees helps preserve the soil and prevents desertification.
  • One tree can absorb 20 kg of dust annually and “swallow” 80 kg of suspensions containing toxic metals such as mercury, lithium and lead.
  • Planting trees is an active way to counteract the greenhouse effect, which causes global warming.
  • One tree cleans, filters and purifies 100,000 cubic meters of polluted air, produces 700 kg of oxygen and intakes 20 tons of carbon dioxide.
  • One person has to plant 200 trees in order to “balance” the pollutants he produces in the course of his lifetime.
  • One tree adds a lot of cheer, color and life to an urban landscape.
  • KKL-JNF has planted more than 230 million trees since its establishment, in an area of around one million dunams, which helps combat global warming.
  •  Thousands of people participate in tree planting in the forests of KKL-JNF every Tu Bishvat and during the year.
  • KKL-JNF has made a commitment, in accordance with the UN Billion Tree Campaign, to plant six million trees over the next ten years.