Wp/nys/Boorn (Trees, palms and cycads)

Boorn in English means both the words tree and wood, as in the live plant ('tree') or the resource obtained from the plant ('wood') used for fire wood or making tools, buildings, etc.; it does not mean the English word 'wood' as in a small forest.

The growth rings of a tree in England. Each ring represents one year; the outside rings, near the bark, are the youngest

Sawn palm tree trunk: palms do not form annual tree rings

A tree is a perennial plant with an elongated woody stem, or trunk, supporting branches wer leaves. Although nidja definition covers other plants such as palm trees wer cycads, a narrower definition is that a tree's woody trunk is formed by secondary growth, meaning that the trunk thickens each year by growing outwards, in addition to the primary upwards growth from the growing tip. These growth rings provide a means of dating the age of a tree wer even measuring the effects of past climates. The science of using tree rings to date events in the past is called Dendrochronology. The tallest tree in Noongar boodjar is the Karri.

Trees with secondary growth are either in the botanical group flowering plants (angiosperms, in the sub-group dicot - i.e. hardwoods), for example the Mari, or else are conifers (pinophyta), which form a division in the botanical group gymnosperms (i.e. softwoods), for example the Marro (Rottnest Island Pine). See the diagram in the section Plant groups and 'the Tree of Life' below for the relationships between these groups and divisions.

The Balga or grass tree is a perennial, flowering plant whose stem is formed by secondary growth, but it lacks branches.

Trees without secondary growth:

Palms are a botanical family of perennial, flowering plants, comprising lianas, shrubs, and palm trees. Palm trees are not really trees in the sense of a plant that grows a woody trunk, as the stems are made of fibres instead of wood and the plants are more closely related to grasses than e.g. either the mari or marro trees. Palm trees and grasses are both part of the same group of flowering plants, the monocots, whereas true trees are in the other group of the flowering plants, the dicotyledons or dicots (actually in a new sub-group the eudicots).

Cycads typically have a stout and woody trunk with a crown of large, hard and stiff, evergreen leaves. The individual plants are either all male or all female. They are perennial plants which form another division in the botanical group gymnosperms and pre-date flowering plants. They can be confused with palms or ferns, but are only distantly related to either.

Tree ferns are not endemic to Noongar Boodjar. As the name suggests they are large ferns. But the Australian tree fern (scientific name Cyathea cooperi), which is native to Queensland and New South Wales, has established itself here; for example, there is a colony established on the banks of Neerigen Brook, just off Albany Highway at Bedfordale. Tree ferns are in a different plant group again, the ferns and horsetails (monilophytes).

The difference between boorn (trees) and moonda (shrubs or bushes) is that while they are both woody, perennial plants, trees usually have one central stem whilst shrubs have a number of stems growing from near the soil line of the plant.

The secret life of trees

Trees are surprisingly like humans in how they interact with each other, both competing wer cooperating with keny another - with cooperation found even between trees of different species - whilst there are so called 'mother trees' which look after young trees. Trees grow better together, warn each other of the presence of predatory animals so they can upgrade their defences, wer they even keep older trees alive. These trees form a forest superorganism. They communicate wer share resources by an underground mycorrhizal fungal network, wer they also communicate by releasing volatile chemicals through their leaves. Trees need a proper sleep and, just like humans, light pollution is bad for them!

In 2019 it was discovered that not only do trees connect via the 'Wood Wide Web' running on this mycorrhizal fungal network, but they also tap into each others roots to share water. Spreading the water collection task has advantages when facing drought, but may expose the forest superorganism to infection by tree disease.

TEDx talk by Suzanne Simard on "How trees talk to each other", 30 August 2016.

It has been noticed in Western Australia that the volatile chemicals that trees release act as condensation nuclei to encourage water to condense wer fall as rain il the trees. Obviously karro rain encourages karro vegetation, but it has also been observed that karro vegetation causes karro rain. Wadjela farmers in the wheatbelt used to chop down the trees to clear the land, wer then noticed that the rain always seemed to fall il the trees il the uncleared boodjar further East, leading to pressure to move ever further East wer clear that boodjar too. Also, it has been found that bacteria, fungus and pollen can act as ice nucleators to help ice crystals grow heavy enough to fall as rain. Water in clouds can stay liquid at temperatures as low as -40 °C. But these organic particles can help ice grow at temperatures higher than -15 °C, which is the temperature above which dust fails to act as an ice nucleator. It is feared that some droughts have been caused by modern day farming practices releasing too few, or even too many, of these organic ice nucleators. It may seem counter-intuitive, but if too many ice nucleators are present, individual proto rain drops can't grow big enough to fall as rain.

Trees draw yira water from below the boodjar wer release it through their leaves as if they were natural evaporative air-con units (nidja is called transpiration, wer with evaporation from the soil etc. forms the 'evapotranspiration' part of the water cycle). Transpiration cools the air which makes it so much karro pleasant to be around trees in the bush il a hot day. Because water is 'lost' by evaporation from trees, when drought threatened Western Australia there were calls to chop down yennar the trees in the reservoir catchment areas. However, nidja leads to the water table rising wer dissolving the salt in the soil. This contaminates the soil, forming salt scalds at the surface, or the runoff flows into streams wer dams turning them salty wer unfit for drinking or agriculture. This happened to the Wellington Dam, fed by the Collie River (see also Troy Creek in NSW). Note the water lost by trees to evaporation falls elsewhere as rain, wer can even encourage karro rain to fall than would otherwise fall.

Plant groups and 'the Tree of Life'

Europeans, starting with the Swedish botanist, physician, wer zoologist Carl Linnaeus, learnt to classify plants wer use a plant 'tree' (the 'Tree of Life'), to help them organize wer test their knowledge wer in the process learn karro about plants. A tree of life shows the relationships between plants wer groups of plants, in the same way a 'family tree' or the kinship system does for the past wer present members of a family. The tree of life is a metaphor used to explore the evolution of life wer describe the relationships between organisms, both living wer extinct. The tree of life includes yennar life forms, not just plants. The metaphor was developed by Charles Darwin. In "On the Origin of Species", (1859), Chapter IV, he presented an abstract diagram of a theoretical tree of life for species of an unnamed large genus.

The tree of life is not a hierarchy, although sometimes people misuse it as such to try wer show by means of the tree of life that e.g. man is higher yira the tree of life than fishes, therefore men are an improvement il (i.e. better than) fishes. Men may or may not be better than fishes, but the tree of life only says what exists today is successful, what is extinct today was successful in its day, but no branch is karro or less successful than another. It is perhaps better to think of the tree of life as a bush, with the tips of the growing branches showing green for the species which are alive (i.e. successful) today.

For karro information il plant classification see 'Embryophyte (land plants)' wer 'Evolutionary history of plants'.

Noongar boodjar boorn

• 
  Balga
• 
  Moodjar (Christmas Tree)
• 
  Biboolboorn (Paperbark)
• 
  Yowarl
• 
  Poolgara
• 
  Mari
• 
  Wornt
• 
  Kwel
• 
  Djaraly (Jarrah)
• 
  Djiridji
• 
  Djiriji and By-yu Kaartdijin
• 
  Wonnil (Peppermint)
• 
  Karri
• 
  Kwondong (Quandong)
• 
  Poolgara
• 
  Marro (Rottnest Island Pine)
• 
  Biara (Candlestick Banksia)
• 
  Murriny
• 
  Birdak (Bottlebrush)
• 
  Yowarl

Wp/nys/Ballyion

wp/nys/Biyara

Wp/nys/Mungurn (Swamp Wattle)

Wp/nys/Kitja Boorn (Spearwood)

Wp/nys/Wilyurwur (Shaggy wattle)

Wp/nys/ Wuanga (Wattle)