TIDE
In the Tejo Estuary the tide is a very important factor, since the average volume of tide (600 x 106 m3) is significant in relation to the volume of water below the lower level of the tide (1,900 x 106 m3). This estuary corresponds to an estuary of the positive type, being also characterized as a partially stratified estuary.
The average annual flow of the river is around 400 m3 / s, subject to a large monthly variation, from 1 to 2,200 m3 / s, with a flood of 14,000 m3 / s.
The tidal regime is of the semidiurnal type, with the flood times being longer than those of the ebb. The amplitude of the tide, measured in the north margin, is increasing from the mouth to Alverca, where it reaches the maximum of approximately 4.8 m, then decreasing until it annul in the region of Muge, about 80 km from the mouth. The average amplitude of tide is 2.6 m, presenting a minimum value of 1 m.
The saline intrusion is felt up to Vila Franca de Xira, 50 km from the bar. In the flood regime, the salinity of the water in the Alcochete / Poço-do-Bispo area is of the order of 10 ‰, while in the drought regime, with the river flows reduced, its values ​​can rise to 25 ‰ .
The tidal amplitude observed and the geomorphological characteristics of its mouth, both upstream and downstream, allow the inclusion of the Tagus estuary in the mesotid estuary class.

The Climate 
The climate of 
the region where the Natural Reserve of the Tejo Estuary is located is of the Mediterranean type, being December and January the coldest and rainy months and July and August the hottest and dryest.

Temperature
 The daily average temperature of the air is between 16 to 17.5 ºC. 

RAIN
The average annual precipitation between 600 and 700 mm 

LIGHT
The average annual insolation between 2,900 and 3,000 h. 

WIND
The prevailing winds are from the north quadrant.

The soil of the estuary
The soil of the estuary presents:
1. Coastal habitats and halophytic vegetation;
2. freshwater habitats.
3. Heavens and weeds of temperate zones
4. Natural and semi-natural herbaceous formations
5. Temperate Europe forests, Mediterranean deciduous and Mediterranean sclerophyll forests.

Coastal habitats and halophytic vegetation

Agriculture and Livestock
The agricultural fields in Leziria Sul, irrigated by a network of freshwater ditches draining to the Tagus and Sorraia, support crops of irrigated land, rainforest and rice paddies. In the Reserve, large areas of pasture are home to livestock, especially the cattle of the lide - the brave bull - which, along with the Lusitanian horse, are the brand image of the Ribatejo grassland.

Saline activity
For millennia, the saline activity was one of the main sources of income of the region and of the country. The deactivation of salinas has been progressively depleted due to the importation of salt from abroad and the progress made in the means of preserving food, especially the aquatic birds that suffer most from the loss of part of their value.
The salt marshes are the physical structures of an activity that shaped the landscape and held a culture of knowledge and living transmitted from generation to generation. It is with the fine salt - the flower of salt - obtained at the beginning of the harvest that the "salt loaves" are prepared, pressed in small parallelepipedic forms in which are engraved elements allusive to the diverse values ​​of the region, most of the time iron of the (as) the owners of the land. To the "white-gold", once collected in the Tejo is attached an important role in the commercial transactions between Portugal and northern Europe at the time.


Fishing
The Alosa alosa sable attracted numerous fishermen from the area of ​​Vieira de Leiria and the region of Aveiro to the estuary, which was also abundant in numerous other species, proliferating, even, oyster banks. However, their numbers have been decimated, or seriously jeopardized, by pollution from urban, industrial and agricultural sources. Fishing activity has drastically reduced, and today only a few boats are engaged mainly in catching sole, bass and eel. The return of species almost disappeared, in the case of the charroco Halobatrachus didactylus, seems to point to a certain recovery of the fishing wealth.
The different fishing gear (nets, traps and devices) reveal the ingenuity of the people who work in the estuary, capturing their livelihood. Among the fishermen's nuclei, there are the communities of avieiros and varinos, based in Alhandra, Póvoa de Sta. Iria and Vila Franca de Xira. They were typical of their fishing ports stilts (built on the water), constituted by a set of piers parallel to each other and perpendicular to the river. The evolution of fishing boats and transport on the river is also part of the cultural heritage to be explored.

Traffic between the two banks

The intense river traffic related to fishing activity and the transport of people and goods was animated by a diverse set of vessels such as frigates, varins, faluas, boats, mill boats, moios boats, catraios, boats of boats, boats, canoes, bateiras, boats of water above, etc. The remarkable variety of shape of the vessels, resulting from the creativity of our shipyards and the style of each one represents a cultural element of great interest. In the 80's of the XX, in order to counteract the disappearance of the frigate, varino and falua, the riverside municipalities of Seixal, Moita, Alcochete and Vila Franca de Xira recovered some traditional vessels, converting them to tourism, recreation or leisure activities and environmental education.

Built heritage
As there are no major buildings inside the Reserve, the built heritage is mainly important due to its connection with the cultural heritage.

The Hermitage of Our Lady of Alcamé was built in the 16th century. XVIII, in neoclassical and monumental style, under the invocation of Our Lady of the Conception, was the appropriate place for the workers of the lazírias there fulfilling their religious obligations. It is located in the Special Protection Zone near the northern limit of the Natural Reserve. At the end of the century, In the 19th century, festivities were held here, organized by a commission of party-goers who were part of Vila Franca de Xira, Alhandra and Alverca. In the 1940s, from the XX, a group of owners resumed the organization of the parties by associating them with the "Incarnate Vest" of Vila Franca de Xira. In recent years, the Varina Association of Vila Franca de Xira has been promoting the pilgrimage through June 17, with the participation of other local associations. The campinos, accompanied by the band and the procession, transport the Andor with the image of Our Lady of the Conception from the Mother Church to the quay, where the boarding ceremony takes place. The procession proceeds along the river, in traditional boats all decked out, to the pier of the Marquis. There, the andor is transferred to a cart, following the procession to the hermitage, where the religious ceremonies are carried out, which include the blessing of the cattle and the camp with presentation of folkloric ranches and activities associated with the cabrests and campinos.

Varino

Catfish, which can decimate other species, was first detected in the Tagus River in 2014. The researchers at Mare - Center for Sea Science and Environment at the University of Lisbon have already captured 12.
The species is classified as opportunistic and necrophagous, feeding on other dead fish at the bottom of rivers, although it eats other fish and even birds or other animals along the banks. "Basically eat everything that fits in your huge mouth"

parasitic nematode Anguillicola crassus

In the aquatic environment itself, the existence of phytoplankton (primary production estimated at 4,400 tons of carbon / year, throughout the estuarine area) is still to be noted; of microfitobentos, predominantly constituted by unicellular algae from the diatomaceous group that proliferate on the surface of the vasas and sands, making photosynthesis while they are exposed to light during the empty tide (estimated primary production in a value close to 11,000 tons of carbon / year, in the entire estuarine area); and of macrophytic algae, represented mainly by the Fucus vesiculosus, the sea bass Ulva lactuca and the gracilaria Gracilaria verrucosa (primary production estimated at 4,000 tons of carbon / year, in the entire estuarine area).

In the terrestrial environment (mouchões, Lezíria sul and Pancas area), the natural vegetation consists mainly of herbaceous species that form natural pastures or grow spontaneously on the edges of cultivated fields, natural pastures, stubble and initial stages of cultivation. Shrubby and arboreal species develop in a narrow sandy strip that crosses the clay fields of the sorzia downstream of Sorraia, as well as in the semi-natural hedge that delimits the Pleistocene terraces at the nascent boundary of this Protected Area.

Some birds, such as Pena-vemelha, feed mainly on small crustaceans, molluscs and polychaetes, but also insects, spiders, fish and tadpoles. Diet, mode of feeding and habitat may vary and depend on seasons and climate. The food is obtained by swimming or walking in areas of shallow water, capturing the prey on the surface or using the spout as a probe.

web of the yew estuary

It is the migratory aquatic bird that gives the Tagus estuary the status of the most important wetland in the country and one of the most important in the Western Palearctic. Here, about 100,000 wintering birds occur regularly, surpassing the value of 120,000 birds during periods of migratory passage. The estuary hosts, on average, about 54% of the waders, 30% of the antidids and 4% of the wintering ardeids registered in Portugal.

The salt produced in the Tejo was once very important in the national economy.
It is currently in decline. 

The disappearance of the salinas entails:
landscape destruction;
reduction of important habitats for avifauna (nesting, refuge and feeding);
disappearance of a profession, cultural values 

saline 

Bivalve picking

To access the IUCN Red List

couple of sparrows

STARTING THE CHORO

Birds are also key determinants of the biological richness of the reserve. "It's a very important area. It harbors populations of several species, which are significant globally, "says biologist Mauro Hilario.
 The places of observation
described here are located in the nascent part - so if it is sunny the conditions of observation will be more
favorable during the morning. In addition, because it is a place subject to the influence of tides, it is
It is advisable to check in advance if the tide is full or empty (the best times to see birds are at low tide or in the next three hours.
This type of habitat is especially interesting to see birds outside the nesting season (ie in the
Autumn and winter). Here you can see several species of waders, namely sand-
large-collared, the gray-billed plover, the right billed tortoise, the common red-leg and the leg-
green. Seagulls are also frequent, especially the common crane and the dark-gull.
Other waterfowl that can be seen here include the heron, the little egret, the
spoonbill and the eagle.

OBSERVATION OF BIRDS

Mata da Machada extends east of N10-3, a few kilometers south of Barreiro. This zone
can only be reached on foot - it is possible to park next to the N10-3, in front of the "Marines".
There are several signposts of varying length that allow you to walk through the woods. As it happens
in densely forested sites, bird watching is not always easy, since they hide
through the vegetation.

The invasive species is acacia.The imbalance caused by invasive plants in some ecosystems is so serious that it may endanger other species. The competitive advantage of these plants is related to the following aspects: (1) they are usually plants that produce many seeds, which are viable for long periods of time and can be stimulated by fire; (2) compete more efficiently for available resources than native species, and (3) usually do not rely on the presence of their natural enemies.

In the project's intervention area we can find the following species of acacia: Acacia dealbata (Mimosa), Acacia longifolia (Acacia-de-espigas), Acacia mearnsii (Acacia-negra), Acacia melanoxylon (Acacia- australia), Acacia pycnantha, Acacia retinodes (Acacia-virilda), Acacia saligna.

With the acacia wood itself the group together with the guidance of the biologist Mauro Hilário, n the context of the recovery of Ribeira do Zebro within Mata da Machada, the students proceeded to the placement of willow stakes and natural engineering (to make dams)

The author of this poem is the biologist Mauro Hilário and has a book with poems in English "Perpectives in mind" of 2018, and another one in Portuguese "Epic - The Ascension" of 2014.
The biologist works on the Biodiscoveries project, at the CEA in Mata da Machada.

Participate in the "Sponsor a Red List Plant" Campaign
see how on the site
http://www.spbotanica.pt/#apadrinhe