What can we find in what a barn owl regurgitates? What kind of teeth has a sheep or an otter? What type of nests do birds make? Do insects also make nests? Are all shells the same? What is the difference between a nocturnal and a diurnal butterfly? How many days does it take for a bird to migrate and which routes do they take? Our exhibition room contains a collection of scientific and information resources about the many species found in the Alvor Estuary. They help us answer these and many more questions. In there we also prepare for hiking to the Alvor Estuary, where it is possible to find and explain different habitats, their importance and status. We can see how a dune is formed, find out what species we can find, what food chains and life cycles exist, migration records and routes and a small collection of skulls and bones from different animals found in the area.
At A ROCHA’s Environmental Interpretation Center we have a nature walk that anyone can visit without a guide. On this walk you can see the different habitats that we have created in order to attract birds. For the same reason, we have a few artificial ponds, areas of pine forest, Mediterranean forest, an orchard and reedbeds that attract many different species of animals – from invertebrates to small mammals, such as shrews and hedgehogs. The nature walk can be visited on those days that the Center is open to the public (Thursday mornings), during the summer months (July to September), and as part of the activities of ‘Ciência Viva no Verão’ and environmental education visits made by schools.
We have three artificial ponds, which help to attract birds and create better quality habitats. One of the ponds is divided into three sections. One of them, which is not very deep, has a reedbed which is visited by different species of birds. In the middle section, which is the deepest, we have small fish that feed mainly on larvae, including mosquitos and dragonflies. The third section is less deep but equally full of insect larvae, such as mosquitos, cavalinhos-do-diabo, dragonflies, damselflies, great diving beetles, mayflies, among others, which are the favourite food of diving bell spiders, viperine water snakes, newts and frogs.
The vegetation around the ponds is a great refuge for most of the animals that depend on it. The relationship between these species and the existing abiotic conditions are essential for a good ecosystem. The great biodiversity of species found in this area shows how importance this biotope is. These artificial ponds are maintained by rainwater and treated wastewater. They are an excellent habitat to attract some of the birds that we ring in our garden, such as kingfishers, common wasbills, Eurasian reed warblers and Southern masked-weavers.
Macrophyte-based Wastewater Treatment Plant
The reedbed is a wastewater treatment station which depends on plants.
The wastewater produced at our center is filtered and returned to the natural water cycle. The wastewater from the entire house is collected in an underground tank where the larger particles settle to the bottom and are broken down by bacteria. The suspended particles are then sent to the reedbeds by gravity. The plants use most of the water that gets here as they have the capacity to fragment pollutants on the surface of their roots.
The water that is not used by plants ends up being collected and transported to the artificial ponds with the help of a solar-powered pump. The maintenance and cutting down of the reedbeds need to be made regularly so that a structurally diverse habitat can be created and does not dry out. Besides being useful to treat wastewater, reedbeds are also an excellent habitat for crickets, grasshoppers, chameleons and birds such as the Eurasian penduline tit and the common waxbill.
Composting is a natural process of turning “rubbish” into organic fertilizer under aerobic conditions (in the presence of oxygen). This process helps us reduce the amount of rubbish we throw away and to improve the quality of the soil for cultivation. The composting not only improves soil structure by increasing aeration but it also supports a wide biodiversity and may even reduce the incidence of pests and diseases in vegetables. The organic “rubbish” comes from remains of uncooked vegetables (with the exception of citrus fruit as their acidity can damage the decomposing organisms), eggshells, tea bags and coffee grounds. They are decomposed by organisms such as bacteria, mushrooms, beetles, worms and mites, which in the presence of oxygen turn various materials into the humus-like product that we call composting.
Organic vegetable garden
We have three small organic gardens at our center. The gardens have different degrees of shade and moisture; it is possible to cultivate different vegetables. The fertilizer we use is the composting produced at the center itself, without any use of pesticides. In our garden, it was imperative that we had this type of cultivation, even though they are small plots. We make use of composting, drip irrigation, localised irrigation and fallow and allow pest control to be done naturally. We have three plots where we grow winter and summer vegetables for our own consumption. We typically cultivate potatoes, carrots, onions, lettuce, tomatoes, peppers, broad beans, beans and some aromatic herbs, such as parsley, basil, oregano and coriander.
In our garden we have a play area and picnic tables where visitors can relax and have a meal.