As part of the AILA Victoria ‘Cultivate’ series of talks a presentation aimed to begin a discussion amongst colleagues was held on the 15.5.08. Registrants were invited to contribute beforehand by email by sending questions, ideas, concerns and statements.
These emails were used to stimulate discussion between the 102 participants composed of landscape architects, students and allied professionals.
The evening began with an introduction from Paul Thompson followed by discussion around the emails presented by the authors and finishing with broad spirited contributions from the floor.
We are to explore strategies for adjusting to change in the two types of landscapes that involve Landscape Architects. They are:
Natural Systems
Designed Landscapes
Climate Change challenges the imagination of designers and managers of vegetation for the future as the past 12 abnormal years become an indicator of what conditions the next 100 years may present.
Climate Change will produce change in growth patterns of all plants due to change in:
..............
Predictability of Variable Climate
- Designers assumptions of future conditions need to be informed by the best scientific information.
..............
Temperature Change for All Seasons
- Increase or decrease in temperature changes the diversity and distribution of species.
- Temperature affects growth rate, size, flowering, setting of seed, and amount of water required.
..............
Rainfall Change
- Frequency of rain events determines the composition of plant groups.
- With reliable rain plants are sustained between growth periods. When unreliable only the most tolerant persist.
- Quantity of rain is related to the amount that may either be stored in the system and become available or run off and be lost.
..............
Plant Growth Period
- Growth occurs when daily temperatures in air and soil are high enough and soil moisture is available and exceeds evaporation.
- Change in temperatures rainfall and humidity affect change for all plants for their viability in the built landscape and distribution in natural systems.
..............
Humidity ~ A secondary effect
- Increase in humidity changes the ultra violet and allows some species to grow in sunshine and some species to become susceptible to pathogens.
..............
Sunshine ~ A secondary effect
- Increased cloud cover, smog and smoke from fires will adversely influence growth.
..............
Wind Patterns ~ A secondary effect
- Reduced wind desirable for plant growth.
- Increased wind may destabilize. Increased wind increases the need for plants to be watered.
Change in Natural Systems adjust to change in conditions where there is diversity and integrity of the landscape.
In intact natural systems one might hypothesize that the balance between numbers of species in the plant community will change. Dominance of particular species or groups of species may alter yet the system remains resilient to change by its ability to replicate.
Species that are naturally wide ranging are believed to be the most tolerant. Species that are limited in their occurrence may be lost.
In degraded Bushland the most likely occurrence is that weeds will proliferate.
Planning and Management will be needed to stimulate succession and redistribution of species.
Landscape planning important to preserve and link disparate remnants.
Action will be required to decrease vermin and weeds.
Natural systems will benefit from increase informed scientific fire management.
Natural Systems biggest benefit will be from greater public understanding and advocacy, public acceptance of natural processes and the increasing need to control damaging access.
Designed Landscapes that exist will either be allowed to morph through management into a landscape of similar function and character or be redesigned.
Species diversity and increased planting complexity is a recommendation for a climate tolerant landscape. Greater rigor is essential for species selection in the design of a durable landscape. Develop a list of new standard criteria for the future condition in the new landscapes. Plantings will need to thrive with climatic extremes.
Ideas of today may not be manifest in the landscape for 20 or 30 years and in the public realm are intended to still be effective for 100 years or more.
All designed landscapes to become realised require informed maintenance where the design intent is understood and adopted by successive managers.
New Landscapes must be designed with greater understanding and control of the soil condition. A reliable, suitable, known ground water condition is essential for successful site specific plant selection. Modified and designed soil conditions are the future in the built landscape. New growing media is ideal when not compactable.
A balance between ready infiltration and retention of water will be increasingly important.On site water harvesting above ground drainage techniques such as Ainslie Village ACT by Glen Wilson FAILA will become normal practice. WSUD practices may need to be adjusted. Water infiltration pavements known for more than 40 years yet rarely exploited will become common.
>> click here to see the comments that were discussed ~ posted to theailablog
