Succession is the change of species and ecological systems over time. In nature, we commonly see this phenomena as areas ravaged by natural disasters gradually return to a complex ecological state. In the context of landscape architecture, this means the purposeful manipulation of this transformation to create stable ecosystems. It is often paired with restoration efforts to foster new and stable ecosystems where there previously were none, or that had been affected by man-made disturbance.
Our landscape succession design takes place in two forms: a swath of land on which a stable ecosystem is cultivated, and specific moments within the larger form that require continuous remediation. These sites are active industrial sites, continuing to release toxins into the surrounding area. They can not, however, be disregarded; they are crucial to the identity of Delray and the backbone of its economy, so we’re preserving them within our design with the caveat that their contaminants are mitigated by the continued use of phytoremediation within their area of direct influence.
Cleansing of the site – both initially and continuously, as with the sites of active industries – takes the form of phytoremediation. Specific plants extract toxins from the soil, purifying the ground to make way for healthy successional landscape flora. By allowing the processes of phytoremediation and landscape succession to coexist within the same areas, not only does this boundary become blurred, but the presence of each type of vegetation is an indicator of the success of the remediation. A lack of non-remediating flora indicates the site is need of major remediation; an abundance of non-remediating flora indicates the remediation is successful, and the new ecosystem can thrive.
Our project spans a 10+ year cycle, adapting based on the remediation and intervention required from the active industrial areas. It begins with a primary disturbance: removing hardscaping. The soil, once exposed, requires intense remediation across the entire site. Once cleansed, the remediation only continues on the most contaminated sites, those which continue to be exposed to industrial toxins. The final phases of the successional landscape continue even past the lifetimes of the industries. The ecosystem stabilizes, no longer requiring remediation or human intervention to support itself.
Ecosystems will distribute themselves naturally as a gradient from the riverfront up towards the Fisher Freeway, based on the changes in soil conditions and other environmental impacts. While not forming distinct boundaries, the general organization of systems is marshlands along the river, followed by a pine barren, then followed by a deciduous forest. Though initially all planted as a uniform distribution of flora, the survival successes and failures of each species will cause these systems to gradually form naturally, establishing stability in its eventual end-state.
Wanting to design with a sensitivity to the context of Delray, we’ve overlaid three particular descriptors of the site in order to determine their relationships to one another. Topmost are the vectors which map the growth and transformation of vegetation over time. In the middle is a trace detailing the currently existing vegetation on the site. The lowest diagram indicates the location of the various brownfields on site, both active and inactive.
Vegetation covers large swathes of the site – some portions cultivated, but mainly unkempt and overgrown. By contrast, the brownfields act primarily along two axes: following the river, and along the rail line. This presents us with an interesting context in which a healthy, or at least less polluted strip of land, is sandwiched between two contaminated regions.