Windbreaks - Design and Construction Considerations
Windbreaks and Forest Zones (WFR). The impact of supertyphoon Megi (Juan), with its double punches of excessive wind forces and massive rain (500-600mm in 24 hours) was highlighted here to emphasize that the windbreaks for tropical countries, like the Philippines must be built with the perspective to address the more unique conditions encountered in wet tropical countries, like the Philippines.
The predominantly long rainy reason (June to November; longer in certain regions or year round in a number of regions) is then followed by at least four (4) months of dry season. However, because of the high temperatures during later stages of the dry season, evapo-transpiration rate exceeds the total rainfall during the first rains of May and even June. The rainy season is also the season for the arrival of a number of typhoons that hit different regions of the Philippines. A longer or more intense rainy reason occurs during the onset of La Niña, while a longer dry occurs during the onset of El Niño. These conditions lead to flash flood, landslides, soil and water erosion during the rainy season, more severely during the onset of La Niña while the potential for drought is quite common during the dry season especially during the onset of El Niño.
Thus, for our EcoCulture projects, the windbreaks zones will be designed beyond what windbreaks are meant for, as outlined in the video. Apart from serving as windbreaks, they will be developed as micro-forest zones (akin to the tropical rainforest ecosystem) within the farm, as well as integral component of our rainwater harvesting and groundwater recharge strategies. These added functions are part of our long term goal to address the question:
How can the excess rainwater during the rainy season be harvested, stored, treated; and, then used during the long dry season for domestic purposes, farm irrigation, livestock husbandry and aquaculture?
Biodiversity. The proposed Windbreaks and Forest Zones (WFR) will be zones of biodiversity, unlike traditional windbreaks, there will be multiple rows and columns of trees with multiple and varying stories of tree canopies. Ecosystem intensification will include tall trees with under storeys of shade trees, shrubs and vines while the outer rows or columns with be plants of partial shade to sun loving plants, perennials and annuals. Deep rooted trees, shrubs and other plants will help anchor the WFR with thicker leaf plants protecting taller trees from high wind forces at the lower levels. Nitrogen fixing trees and plants will be integrated in the array to help provide nitrogen fertilizer.
Fast growing trees and shrubs will be integrated at the initial stages of the development of the WFR to accelerate its role as a windbreak zone. These fast growing trees will include coppice plants to allow regular and drastic pruning and avoid shading of the slow growing trees that will serve as the anchor (tall) trees in the mature WFR.
Flowering (Fruit bearing) Plants and Trees will provide the nectar and pollen to attract bees, other insects and animals, as well as provide source of food for many birds and animals. In turn, the harvested fruits will provide another source of diversified income for the EcoCultule farm.
Biopesticide resources. Trees like the Neem tree will be integrated in the WFR to serve as source of biopesticide. The leaves of the Neem tree are included in storage containers to mitigate postharvest damage from insect and microorganisms that attack or infest stored rice and corn. The leaves are ground and soak in water to extract a biopesticide juice used to spray in plant. Unfortunately.the biopesticide component is light sensitive so the spraying must consider this limitation when used.
Biological Pest Control. The biodiversity of the WFR will attract biodiverse groups of insects, birds and other animals and organisms as well as their own predators that will allow more biological control of pests that are part of any living ecosystem. The relatively undisturbed subsoil of the WFR will serve also as ecosystem for growth of soil and subsoil organisms and microorganism to improve soil health and help in biological control of pests.
The addition of water ecosystems, e.g., ponds, canals, swales, as well as riparian zones, will add another layer of ecodiversity in the EcoCulture farms, in turn introducing additional groups or organisms and microorganisms for more ecosystem approach to checks and balances of organisms and microorganisms that would otherwise become pests.
As much as possible, indigenous plants and organisms will be integrated in the development of the Windbreaks and Forest Zone (WFR). However, deep-rooted plants from reliable sources will be included to help anchor the WFR zones.
Beekeeping. When the windbreaks and forest zones are extensive enough, it may be possible to culture bees within the EcoCulture farms. The bees will be critical for pollination of many fruit bearing crops and trees, and have the added benefit as additional source of income (honey, wax, etc.)
Kahon-kahon. The term kahon-kahon is a Filipino term that may be considered to mean "to place in boxes". I encountered the term first use in water sequestration, akin to the ability of rice terraces to serve as thousands and thousands of micro-dams holding water from the top of the mountain all the base. When it rains therefore each "terraced box" has the capacity to hold more water up to the top of the packed bund or the height of the "micro-spillways" designed to let water flow from the upper terraces to lower levels -- the process repeated until the collected rainwater reaches the lowest terraced land before it spills over to the adjacent stream at the base of the terraced mountains.
While the rice terraces technology has been perfected thousands of years back, the rice terraces intricate and integrated (holistic) structure is one of the most efficient in rainwater storage at the surface as well as in water percolation to re-charge the underground water reservoir.
A similar "kahon-kahon" design will be adapted for our proposed windbreaks and forest zones (WFR) with some gaps to allow access to/from each segment of the EcoCulture farms. Unlike large area farms in the US (ranging from hundreds to tens of thousands of acres of land), the average farm in the Philippines may average in size of about 1-3 hectares or less.
- << Prev