The food forest of La Evidencia will also be the foraging place for some herbivores because their presence is good for the ecosystem, the benefits are:
1. Biodiversity maintenance: By eating a wide range of plants, herbivores prevent one species from becoming spatially dominant over the others. Also, herbivores act against the harmonization of habitat, which allows for coexistence of several species that occupy different niches, hence biodiversity is increased.
2. Recycling of organic matter: The ecological role of any predator (herbivores being predators whose prey is plants) is to gather, by feeding, nutrients and energy over a wide foraging area and store them for short or longer term in their bodies, within their organism; Then, concentrate these resources on a small place in their feces. Of course, the efficiency of this resources restitution is not 100% since the predator will use a percentage of these for its metabolism and to maintain its own homeostasis. Due to the mechanical and chemical actions of herbivores' stomachs as well as the bacterial decomposition in their intestines, their feces turn out to be detritus of plant matter. Once on the ground, these detritus will feed the soil microorganisms which, in turn, allow the absorption of nutrients by existing or nascent plants. In this context, the presence of herbivores, allows recycling of plant material to occur more quickly. The faster the recycling, the greater the quantity and nutritional value of biomass production.
3. Soil health and structure: By feeding soil microorganisms with their feces, herbivores allow them to be abundant in the soil. These ensure (i) high fertility [I invite you to read the previous article on soil micro-organisms and their symbiosis with plants, here]; ii) limit micronutrient deficiency for plants, (iii) balance between different species of microorganisms (thus preventing population development of pathogenic species), (iv) good soil structure and porosity (therefore good water infiltration capacity of the soil and good soil accessibility for the roots). However, the ecosystem will benefit herbivores only if their presence is not permanent; vegetation needs time to recover and recover between two predation episodes. That is why we decided at La Evidencia to follow the principle of holistic management.
Concretely, we have as objective to start with 2 horses, 2 pigs and 2 goats that will be allowed to graze only in one of the branches of the food forest at the same time for 2 weeks. After 2 weeks, another branch of the star will be fenced and the animals will be able to graze only in this new plot for the next 2 weeks. So on, in this way, each plot will have 2 months of recovery time before welcoming herbivores a second time.
We have selected three species of farm animals (pig, goat, horse) for their diversity of diet to ensure that any organic material found in the soil will be consumed and recycled (i.e.: herbs, plants, bushes, fallen fruits, sheaths, fungi, insects, etc.). The star shape allows animals to have access to the water source, which is in the centre, whatever branch they occupy. It helps us not have to move water from one parcel to another.
Poultry will have the opportunity to go wherever their wants and needs take them. Soil, vegetation and animals benefit from the presence of poultry, these benefits are: 1. Aeration of the soil surface layer: Poultry scrape the ground with their paws in search of Arthropods, Annelids and Nematodes to feed. This action results in an aeration of this soil layer in which the micro-organisms need a lot of oxygen in order to decompose all the organic matter on the soil. Also, organic matter is mixed with the surface layer of the soil after the passage of poultry, allowing the soil to remain more porous and permeable to water infiltration. 2. Pathogen control: By eating Arthropods, Annelids, Nematodes and their larvae, poultry prevent the development of pathogens or vectors of plant and animal pathogens. As a result, poultry ensures that the soil remains “healthy” and prevents the occurrence and spread of any disease among individuals, plant and animal, in the ecosystem. 3. Fertilization: Like any predator, poultry accelerate the recycling of nutrients and energy from what they feed. Their feces feed food to soil microorganisms, so fertilizer.
As mentioned above, poultry such as chickens or quails tend to scratch the ground when searching for food. This scraping action can be deleterious in the vegetable garden, a place where the roots are very fragile and superficial. In order to get around this problem, the Mandalas gardens will be inaccessible to chicken and quails thanks to a physical barrier: the water basin that will surround them. The water basin ensures that Galliformes «scraping» birds (like chicken) stay out of the garden while Anseriformes «non-scrapping» birds (like ducks) will have access.
The house for egg-laying will be placed in the centre of the star-shaped feeding forest in order to be easily accessible to the Galliformes and Anseriformes as well as for practical reasons of egg harvesting.
Other animals that can help us with soil fertilization and organic recycling are bats (order: Chiroptera). Bats are nocturnal and usually defecate under their day shelters resulting in their feces (called guano) falling directly to the ground. Bat droppings are a concentration of all the food they have fed over their course, sometimes very long travel for feeding. As we can imagine, the richness of specific elements will depend on their diets. Within the Chiroptera order, two sub-orders allow us to distinguish, roughly, two different diets: (i) Megachiroptera, which is guided by vision, eat fruits, nectars and pollen; (ii) Microchiroptera use echolocation to locate the insects they feed on. In order to benefit from the fertilizing potential of bat guano, we must attract bats to La Evidencia and give them access to a place to sleep during the day (roosting place). Megabats will be attracted by cultivating trees and plants whose fruits, pollen and/or flower are consumed by them. Microchiropters will be attracted by bringing insects together near a light bulb at night. Insects that approach an artificial light source at night are trapped and can no longer move away from it. Nocturnal insects evolved to navigate in the moonlight. By keeping the moon’s light source at a constant angle, they maintain a steady, straight flight. When an insect flies near an artificial light source, it takes it as a landmark rather than the moon. Since the light source radiates in all directions, the insect fails to maintain a constant angle with the light source and its finite straight stroke becomes a spiral dance around the light source.
If bats have shelters to spend the night near their "bait", the probability that they spend the night at La Evidencia is increased. These shelters can be either natural (palms and other large undergrowth plants where they "roost" naturally) or adequate human constructions.
Then we just have to harvest the guano at the foot of the shelter and use it as a natural fertilizer. Bat guano is very rich in nitrogen, phosphorus and potassium. The services that bats will give to La Evidencia are:
- Fertilization
- Pollination of species whose flowers are not very attractive to insects (such as banana flowers) and have evolved for chiropterogamy (eg mango, banana, cocoa, ...)
- Dispersion of the seeds of many trees
- Control of insect populations (mosquitoes, Coleoptera, Trichoptera, Heterocera, ...) that can be harmful to plant production and / or human well-being
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