natural ressources and conscience
The primordial atmosphere
Today, our atmosphere is composed of about 21% of oxygen, 78% of nitrogen, and 1% of small quantities of various gases: argon, neon, hydrogen, etc. But it has not always been so! It is estimated that Earth's primordial atmosphere - about 4.5 billion years ago - was mostly composed of hydrogen, nitrogen, carbon dioxide (CO2), ammonia (NH3) and methane (CH4). No oxygen, therefore! Or in very small quantities, of the order of only 0.0001%.
Therefore, we are talking about the absence of O2 gas , at that time. Paradoxically, the oxygen atoms were all there, and they were even among the most abundant elements on earth. But for the most part they were linked to carbon to form CO2 or trapped in rocks of the crust and mantle.
Cyanobacteria were the first to invent photosynthesis as we know it. From CO2, water and solar energy, these bacteria - sometimes also called blue-green algae - were able to capture the carbon in the CO2, while rejecting oxygen! Unlike plants (which convert mineral nitrogen into organic nitrogen) and animals (which convert organic nitrogen into another organic nitrogen), cyanobacteria (and a few others) are able to take nitrogen directly into the air, gaseous form, and turn it into organic nitrogen. They thus put 100 million tons of mineral nitrogen a year at the disposal of plants on the planet.
All this changed with the appearance of life about 3.5 billion years ago. A key element of life as we know it, is the ability to produce organic carbon molecules (such as carbohydrates, proteins or lipids), which serve as sources of energy. To make them, living organisms have to find carbon. The first bacteria found their carbon by picking up what came within their reach as nutrients (humans do the same). But about 2.7 billion years ago, a new type of bacteria appeared: cyanobacteria.
Possibilities for lodging such visitors are being considered.
The study of the impact of vegetation on climate temperatures and hydrology is a new discipline.
This multi-disciplinary activity seeks to provide key notions about the role of vegetation and to give contextual results.
It is difficult to generalise results given the variability of various determining factors which are more or less wellknown.
The term "vegetation", for example, covers a wide diversity of species with different physical and physiological properties: resistance to drought and evapotranspiration, colour and albedo, density and leaf persistence, etc. Local meteorological conditions (sun, wind,and hydrology) vary significantly in the urban environment. Management also plays a major role which is complex to standardise and evaluate.
The impact of vegetation in a polluted environment is no longer questioned, but adaptability remains a question which requires a great deal of research.
Ecosystemic services are fundamental to the urban environment.Major cities must confront demanding environmental objectives which may sometimes seem contradictory, such as densification to limit urban spread, biodiversity maintenance, anticipating and limiting climate change, the reduction of greenhouse gases and providing a healthy and agreeable environment for the inhabitants. These issues must be taken into account at every level of urban spatial intervention and be monitored over time. Practically speaking, this requires constant interrogation about the relative roles of urban and vegetation forms. Unlike a botanical garden, our aim is not to register a maximum number of plant specimens in an encyclopedic manner. Rather, the aim is to carefully choose endemic plants or introduce exotic plants which have a great capacity for adaptation and can interact directly with our urban environment. We will specifically target medicinal plants, creating the possibility to reintroduce them and study them in an urban context.
The choice of a physic garden was evident, given the training received by one of the collective member, who has a diploma in phytotherapy.
Through the development of a physic garden, we can also contribute to the discovery and rediscovery of medicinal plants, highlighting the didactic and educational aspects of officinal plants and the wonders that nature provide us. Also a digital herbarium could be made available to the general public.
Integrated in an urban zone, a physic garden is part of an overall aim to reintroduce plants which are rarely or not at all present in the urban environment, despite the beneficial high potential for co2 sequestration inplants such as lemon thyme, wild chicory, as well as mallow.
Medicinal plants and their flowers contribute to pollination, which promotes the reproduction of plants and preserves bees in the urban environment. A physic or medicinal garden, also named in Latin: hortus-medicus, herbularius, erbarium-botanicum, hortus botanicus (the wider sense: botanical garden) is where plants with medicinal properties, also These often include herbs also used ascondiments, such as thyme, sage, balm and hyssop.
In France, we work on buildings certified HQE® (High Environmental Quality), H & E (Habitat & Environment), BBC effinergie (Low Consumption Building), Passivhaus and BEPOS (Positive Energy Building). At the international level, we work with BREEAM and LEED certification.Learn More
Created in the 1990s in the United Kingdom, it is the oldest repository in terms of sustainable construction. With more than 250,000 certified buildings worldwide, BREEAM now has international visibility.Learn More
LEED® certification, Leadership in Energy and Environmental Design, is an environmental certification for buildings initiated in the United States in the year 2000 by the US Green Building Council®. More than 100,000 LEED projects are certified or currently being certified in more than 120 countries. Each level requires a minimum of points:Learn More
The "Grenelle Environnement 2012" thermal regulation, known as RT 2012, is a regulatory tool for new residential and tertiary buildings. It aims to improve energy consumption by setting a maximum limit.Learn More
The WELL Building Standard (WELL) focuses on the people in the building. Over the last decade, green building standards and standard-setting organizations have made significant strides towards the market transformation of the building industry, resulting in a rapid expansion of green buildings and environmentally conscious building practices throughout the world.Learn More