Abstract Green roofs have been heralded as a “sustainable building practice” in cities throughout the world as one response to mounting environmental stresses. A range of stressors plus erosion of aesthetics and human well being in urban areas have initiated policies and practices often with incentives to develop green infrastructure such as green roofs. They provide a suite of public and private benefits most of which map onto services generally provided by the ecosystem. Green roof development imbeds in environmental design processes and is constrained by both human and environmental factors. As relatively small, simple, anthropogenic ecosystems, green roofs relate to several existing conceptual and applied ecological ideas. Understanding and applying from ecology and ecosystem studies, ecological engineering, managed ecosystems, construction ecology, urban ecology, landscape ecology, restoration ecology, reconciliation ecology, soil ecology and community ecology show green roof ecosystems can be created to cycle energy and nutrients. Furthermore, green roofs can be constructed to model an ecosystem and may provide a setting for testing ecological concepts. This book takes an ecosystems approach to describing a large number of interactions on green roofs placing them in the total human ecosystem.
https://bioscience.oxfordjournals.org/content/57/10/823.full.pdf
A biodiversity green roof at the Californian Academy of Science. Great habitat for birdlife and succession planting of native plants. Skylights provide for an indoor tropical garden.
A Christmas trip to this distant location from my home lets me explore biodiversity and ecosystem services as provided by a seemingly arid landform of Australia.
Hundreds of kilometres of wheat and sheep farming country, recently harvested its the middle of summer here and 40+ degree celsius would not allow new growth.
Water courses are rare, particular with visible water. They provide key habitat for a large range of organisms and vital ecosystem services.
The wheat fields are all but harvested along the road to the city of Albury, there are hundreds of kilometres fields covering 10’s of thousands of hectares. This soil and land provides a huge part of the worlds food crop for bread production. China is a large customer of wheat and flour. A 15 metre wide harvester lets a farmer crop his 1000 hectare paddocks in quick time. He tills his field to reduced weeds for next years sowing and spreads lime to improve nutrient availability. Soil chemistry and microorganisms plays such an important part of a farmers yield per hectare. Soil depths are very shallow in this oldest of continents. Great care is required to manage our soils that thin crust that supports us all. Another strategy involves no till farming where microorganisms are less disturbed to do their magic, although this technique relies on increased herbicide use and whatever damage that does to biodiversity. Wheat crops in this area are not irrigated. A farmer needs to rely on rain, generally the area provides adequate falls but too much or too little at the wrong time spells disaster for the crop. A good farmer will provide flora and fauna corridors along his water courses.
The wheat crop growing July 2012 near Urana NSW.
Eucalyptus camaldulensis (River Red Gum) providing soil stabilisation services to a highly erodible landscape. E. camaldulensis is the most widely spread of our 500+ species of Australian Eucalypts. The key to erosion control is to always provide vegetative cover, this avoids desertification.
Our shallow soils need care
A farmer ploughs twenty four seven, to provide his crop
He relies on climate, as do we
He feeds, we feed
Nature relies on us, we rely on nature
Careful thought is required
Robert Griffith
The native Blue Banded Bee Amegilla cingulata finds and exotic host in the Prickly Pear Opuntia stricta. This cactus once took over 40,000 square kilometres of Australia and was a catastrophic weed species. Luckily we engaged the biological services of Cactoblastis cactorum a butterfly and natural predator of Prickly Pear in its home of South America. Cactoblastis has successfully controlled Prickly Pear and has made available tens of thousands of hectares of land for farming and biodiversity in Australia.
The Kingfisher, Todiramphus sanctus rests on a branch in western New South Wales. They nest in hollow logs on trees or mud holes in creek embankements.
A great old River Red Gum, Eucalyptus camaldulensis with roots following the water course. Their timber is so strong it can withstand huge floods. See next photo of this same creek in flood.
Water is a scarce commodity in western NSW, Australia. In agricultural areas of 500 – 700mm precipitation per year provides just enough for wheat and sheep farming, the most common practices. Canola an oil crop is also common.
Irrigation in this country is rare as creeks have a habit of drying up or flooding wildly. The Eucalyptus camaldulensis or River Red Gum is the dominant species along creek lines in western NSW. Evolution with natural selection has deemed that species find their niche. E. camaldulensis has the ability to withstand inundation in water courses unlike most other species. It’s timber is exceptionally hard (a terrific hot burning firewood). This gives the tree fantastic strength to withstand huge floods that periodically occur in Australian inland rivers. Its life cycle strategy is to drop millions of seeds per year, in a good season thousands of seedlings spring up in the wet mud. This tree species provides erosion control for our river systems, holding the creek banks from washing away. The tree itself provides excellent forage for bees and is host to many insect species. Old and narly branches are often hollowed out by termites and in turn provide safe nesting spots for a variety of birds and arboreal mammals. E. camaldulensis is a great provider of ecosystem services.
The 2013 flood of Urana creek. It flows 3 metres deep in this flat country and includes the town. The creek normally less than 3 metres wide swells to 6 kilometres in width and causes damage to towns. It is a natural occurrence and refills the inland lakes and seas. This is a 1:100 flood but it also occurred in 2012. The water results in millions of birds from all over the world flocking to our inland lakes and dining on abundant snails and fish.
One species is the Eastern Brown snake Psuedonaja textilis is something to look out for. Beautiful they are quick to get out of your way but don't play with this one they pack a deadly bite.
Branches litter the ground as do leaves, providing nourishment and habitat.
A Grass Parrot Psephotus haematonotus is a common bird in the Urana Lake campsite reserve.
Wind does its bit to spread the seed of this Scotch Thistle Onopordum acanthium. Not a native but abundant never-the-less over thousands of square miles in Australia. It is a major weed species of farmland.
A young Eucalyptus camaldulensis is born among the leaf litter and gum nuts.
The old railway bridge has trees growing through it and is a home for busy termites slowly turning it into compost. Now that cars are mass produced the railways have systematically been closed across NSW.
Nothing like watching the sunset in western NSW with a glass of wine. The red colour comes from the red dust further west in the Simpson Desert. Perhaps the story of my next blog.
A narly red gum shows its history
Floods and droughts of two hundred years
It drops its million seeds on wet mud banks
Dry leaves crunch underfoot
Ants of many types scurry in the hot sun
Creek banks are littered with branch habitat
Ducks, lizards and snakes enjoy
The muddy creek is full of carp
That’s western NSW
Robert Griffith