Ecology of Sydney


The ecology of Sydney, located in the state of New South Wales, Australia, is diverse for its size, where it would mainly feature biomes such as savannas and some sclerophyll forests, with some pockets of mallee shrublands, riparian forests, heathlands, and wetlands, in addition to small temperate and subtropical rainforest fragments.
There are 79 vegetation communities in the Sydney metropolitan area that are identified, described and mapped. The combination of climate, topography, moisture, and soil influence the dispersion of these ecological communities across a height gradient from. There are many hiking trails, paved and unpaved roads for exploring the many different biomes and ecosystems.
Savannas, the most predominant biome in the Sydney region, mainly occur in the Cumberland Plain west of Sydney CBD, which generally feature eucalyptus trees that are usually in open, dry sclerophyll woodland areas with shrubs and sparse grass in the understory, reminiscent of Mediterranean forests. The plants in this community tend to have rough and spiky leaves, as they are grown in areas with low soil fertility. Wet sclerophyll forests, which are part of temperate forests, have narrow, relatively tall, dense trees with a lush, moist understory of fleecy shrubs and tree ferns. They are mainly found in the wetter areas, such as Forest District and the North Shore.
It has been calculated that around 98,000 hectares of native vegetation remains in the Sydney metropolitan area, shaping the geography of Sydney, about half of what is likely to have been existing at the time of European arrival. According to the Senseable City Lab at the Massachusetts Institute of Technology, which measures canopy cover in the world's most prominent cities, the Sydney area had a Green View Index of 25.9%. Tying with Vancouver at that percentage, Sydney is the third prominent city in the world with the most trees after Singapore and Oslo, respectively.

Historical descriptions

General topographical descriptions

In 1787, the First Fleet personnel discovered a landscape that was alien to them, and unlike the green meadows and deciduous forests of England. Arthur Phillip expressed that:
This was a response to comparisons with the mostly deeper, fertile soils of the British Isles and how the rocky mountainous areas like the Scottish Highlands and Dartmoor lacked tree cover.
The "neck of land" which separates the southern part of the harbour from the northern part was primarily sand. Between Sydney Cove and Botany Bay the first area is made up of woodland. The rest of the land consisted of heath, poor sand and several swamplands. Coastal areas featured mangroves in many inlets, estuaries at Port Jackson, in addition to decentralized areas of saltwater or freshwater marshes, and sheltered areas of subtropical rainforest along waterbody valleys.
Most of the North Shore and inland areas featured sclerophyll forests and woodlands filled with eucalypts of many different species, ranging in different heights, and growing at immensely contrasting densities. Much of the wooded land had grass cover under the trees, but comparatively small understorey shrub or smaller tree growth. Cumberland Plain, which is inland, had sparser and fewer tree cover than the region near the coast. By May 1789 much of the thick forest around Port Jackson was cleared.
First Fleet surgeon George Worgan described the environment of Sydney, particularly its terrain:
In 1819, British settler William Wentworth described Sydney's vegetation and landform in great detail:

Positive

Early settlers compared the landscapes to the manicured parks of England which also featured well-spaced trees and a grassy understorey. In 1787, Arthur Bowes Smyth from the First Fleet described the landscape in a favourable manner:
Captain John Hunter, who criticised Sydney for having "poor, sterile soil, full of stones", had a more positive view of Rosehill's and Parramatta's landscape, which are further west, for having arable lands, stating:
In 1791, Watkin Tench stated that many alien plant species, which included fruit and vegetable productions, thrived very well in the Sydney soil and its climate, although intense heat did affect gardens, and unestablished plants "were withered by the power of the sun". In the following diary entry, Tench positively describes the horticultural scene in western Sydney:
First Fleet surgeon, Arthur Bowes Smyth, acknowledged the beauty of scenery:
In 1827, Peter Cunningham described the western plains of Sydney as "a fine timbered country, perfectly clear of bush...through which you might, generally speaking, drive a gig in all directions, without any impediment in the shape of rocks, scrub or close forest.".

Negative

After landing, the First Fleet thought that Botany Bay was an inhospitable, swampy piece of land which lacked a source of drinking water, in addition to the area featuring poor, sandy soils that did not have any substance. Arthur Phillips writes:
Regarding Phillips' statement, Australian environmentalist Tim Flannery wrote: "The vegetation the early Europeans found growing on the Sydney sandstone both delighted and appalled them...the hungry settlers realized in despair that this magnificent vegetation offered little sustenance". Moreover, the First Fleet's reaction to the Botany Bay area was so negative that Phillip and his crew almost instantly explored further north, towards Port Jackson and Broken Bay.
Upon arriving in Port Jackson, First Fleet lieutenant David Blackburn wrote that Sydney Harbour was "either Immense Barren Rocks, tumbled together in Large Ridges which are almost Inaccessible to Goats, or A Dry Sandy Soil and A General Want of Water". First Fleet officer John Hunter also described Sydney Cove as "very bad, most of the ground being covered with rocks, or large stones".
In July 1788, Lieutenant Ralph Clark, a member of the First Fleet, expressed a scathing view of Sydney's landscape, climate and as well its inhabitants, writing:
In a 1793 commentary map by Watkin Tench, the overall notion was that most of Sydney was agriculturally poor – The land around South Head was "exceedingly rocky, sandy & barren"; the area northwest of Botany Bay was "sandy barren swampy Country"; the coastline from Manly to Mona Vale was "sandy, rocky and very bad Country", the Ku-ring-gai Chase area was "very bad & rugged", the Cattai area was "very dreadful Country", and the southwest of Prospect Hill was a "bad Country frequently over-flowed".

Biomes

Vegetation

The most widespread eucalyptus species in the Sydney region include:
Non-eucalyptus tree species:
Common shrub species include, but are not limited to:

Introduced

Introduced shrubs and/or vines that are invasive species:

Hardiness zone

Due to the microclimate, the plant hardiness zone in the Sydney area would range:

Wildlife

The fauna of the Sydney area is diverse and its urban area is home to variety of bird and insect species, and also a few bat, arachnid and amphibian species. Introduced birds such as the house sparrow, common myna and feral pigeon are ubiquitous in the CBD areas of Sydney. Moreover, possums, bandicoots, rabbits, feral cats, lizards, snakes and frogs may also be present in the urban environment, albeit seldom in city centers.
About 40 species of reptiles are found in the Sydney region and 30 bird species exist in the urban areas. Sydney's outer suburbs, namely those adjacent to large parks, have a great diversity of wildlife. Since European settlement and the subsequent bushland clearing for the increasing population, 60% of the original mammals are now considered endangered or vulnerable, and many reptile species are experiencing population diminution and are becoming elusive.

Tetrapods

This list includes bird species that are widespread in the Sydney metropolitan area:
Although not commonly spotted, these birds are also present in Sydney:
This list includes mammal, reptile and amphibian species that are spotted in the Sydney urban area:

Arthropods

This list includes insect, spider and centipede species that are commonly present in Sydney: