Author: Dr. Eric Van Den Berghe / Profesor Asociado, Departamento de Ambiente y Desarrollo
We are all vaguely aware that forests are important for water production, but it is less obvious how exactly they work and what role non-tree plants play. The forest is an ecosystem with many organisms that act together to capture, retain and recycle water.
When you look at a hill, you will see that, although the sky on all sides is clear, there are clouds on its top. This is not a coincidence, the clouds literally form in the hills especially at night, at dawn, and in the late afternoon. This happens because the same forest releases water into the air in a process called evapotranspiration.
Evapotranspiration helps saturate the air with water. Combined with reduced temperatures in shade, the air becomes over-saturated and causes condensation of clouds. Clouds are made up of millions of tiny droplets suspended in the air, most of the time they are light enough to be suspended and do not fall in the form of rain. However, when they pass through the forest, the plants comb these droplets. And when they come in contact with a leaf they stay there, forming drops.
The denser a forest, the more water is retained from the clouds or mist without the presence of rainfall. This produces a drip called horizontal rain that is very important especially during the dry season. Studies by ZAMORANO in the Cerro Uyuca have measured the production of water by horizontal rain during the dry season (no classic rain). An accumulation of around 200mm of water was detected in the process.
Trees are vital in this process, but they do not act alone, each tree serves as a host for a number of plants attached and rooted in them. This includes ferns, mosses, bromeliads, orchids, and the so-called “pastures”, these multiply the surface of leaves of the tree and therefore its capacity to capture water.
Many plants such as mosses act as sponges, absorbing water so that the liquid does not drain immediately, but remains stored when rain falls. These plants are not parasites, but help the tree in the capture and production of water.
Christmas, a death risk for moss
Sadly, despite our increasing demand for water, we continue to reduce its production capacity in forests. For example, it is a Christmas tradition in Latin American countries to use many of these plants as decorations for Nativity scenes. Unfortunately when these plants are uprooted, we not only condemn them to certain death, but also reduce the forest’s ability to provide water.
As a measure of protection in Honduras, there are now national laws by the Institute of Forest Conservation (ICF) that prohibit the extraction and sale of these plants.
The penalty includes the confiscation of the product, as well as fines for those involved, both buyer and seller. It is recommended to use straw for Christmas Nativity scenes, as customary in other countries.
Publicaciones en los medios:
Source: El Heraldo, Honduras
Source: El Informativo, Honduras
Source: Revista Proagro