Plant of the Week

It’s quiet here today as I realized the journal article I brought from home is actually largely irrelevant, loaded with theoretical mathmatics and ergo, ripe for the recycling bin. I’m also flat out preparing for my trip to Coastal NSW on the 20th (flying out at 6.40am ^^..^^) so it’s nice to take a break from arranging permits and getting identification books sorted out.
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So, this week’s plant of the week is another member of the pea family (Fabaceae), one of the few native peas found in New Zealand, apart from the kowhai (Sophora spp.) and native brooms (Carmichaelia spp.).

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Kowhai-ngutu-kaka – Clianthus puniceus – Kakabeak

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This plant is really striking, with beautiful red flowers that apparently look something like the beak of the native Kaka (Nestor meridionalis), hence the common name.

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Kakabeak flowers look remarkably similar to the other pea that I have profiled Sturt’s Desert Pea, that the latter was originally classified in the Clianthus genus before being reassigned to Swainsona. Kakabeak is now the only remaining species within the Clianthus genus.

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Despite being a popular garden cultivar, Kakabeak is actually a threatened native species. It occurs naturally in the East Cape/Hawkes Bay area, where only about 200 wild individuals survive. Most of the garden varieties that people have are clones or cultivars, which means that the genetic diversity of the species is actually far smaller than what would be expected from the number of individuals alive. In the wild, Kakabeak is threatened by goat, deer, pig and possum browsing.

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Outback Australia NSW

In August and September last year I spent two weeks in the outback, around the area of Broken Hill, Fowlers Gap, and right up in the north-western corner at Sturt National Park, collecting plants for my Masters. I travelled with Tony and Viv Whitaker, who provided the most amazing field support. Tony, as I mentioned in my last post, is a herpetologist who travels all over the world doing field work for varied individuals and organisations. It was an absolute pleasure to travel with Tony and Viv, who were invariably optimistic and motivated in the face of the law of diminishing return.We flew into Sydney and then straight to Broken Hill, where we spent one night before heading onto the road up to Fowler’s Gap, a research station of the University of New South Wales. We stayed in a little single room cottage running solely of solar and wind power, of which there are plenty in the outback.

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The Ochre Cottage

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The Barrier Ranges around Broken Hill

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The landscapes are just phenomenal; they really have to be seen to be believed. Gibber plains – the eroded remnants of billion year old mountain ranges represented today by the low lying Barrier Ranges – stretch on for hundreds of kilometres. The roads are criss-crossed dry creek beds that flood during the rains in winter, but remain dry for 90% of the year, bordered by Red River Gum (Eucalyptus camaldulensis) which dominates the land along with Belah (Casuarina pauper), Mulga (Acacia aneura), Dead Finish (A. tetragonophylla) and millions of saltbushes, daisies and peas.

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A common sight

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A not so common sight – Swainsona fissimontana after rain

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Probably the hardest thing to grasp about the area is that every square metre, except for those in the National Parks, is farming land. Where you see the ground covered in nothing more than rock and sand, you will see fences. It is incredibly unproductive and extremely damaging on an already vulnerable environment. Communities essentially collapse there because the slow growing vegetation simply can’t withstand the herbivore pressure from cows, sheep, goats and kangaroos. Of course with the vegetation gone, the invertebrate and invertebrate communities also suffer. Not to mention the pressure on the Murray-Darling water system that farming here places. But of course, no one would dream of suggesting that farming ought not to be undertaken in the deep deep Outback because, well ‘it’s a way of life’. One that probably won’t last too much longer.

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Grazed Land at Fowler’s Gap

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Non-Grazed Land at Fowler’s Gap – The Mulga Reserve

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The land to the left of the fence is grazing land.
The land to the right has been fenced off for 30 years (the Emu Pen).

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After Fowler’s Gap, we stayed in Sturt National Park, a protected area in the topmost corner of New South Wales. We stayed at the Mount Wood Historic Homestead, administered by the NSW National Parks and Wildlife Services and run by the amazing head ranger, Ingrid. Ingrid was a German PhD student studying kangaroos at Fowlers Gap who fell in love with the Outback and its kangaroos, and now nurses orphaned joeys back to health – with the help of pillowcases as surrogate pouches. She has an incredible amount of energy and passion for her job, which was inspiring. We should all hope to love our jobs with that much passion. The lack of grazing in SNP has allowed for a fantastic regeneration of the vegetation – where in Fowler’s Gap the land was barren and rocky, the plains of SNP are covered with beautiful herbs and shrubs.

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Ingrid and her ’son’  

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You can see why she fell in love with them…

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The outback is a harsh but beautiful place. It can kill you easily if you’re not careful or prepared. But if you look closely enough you can see a world of colour and life, animals and plants that are so beautifully adapted to their environment, unique in their evolutionary histories. I hope that more Australians get the chance to experience it, and learn to treasure it.

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Me

View my slideshow here

Plant of the Week

This week’s plant of the week isn’t actually a single species, but rather a group of plants that have become endangered in New Zealand – the representatives of the Loranthaceae family, or mistletoes.

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Mistletoes are found throughout the world, and it often comes as a surprise that we have a number (8) of native species here, so absent as they are from public consciousness. Granted, they are certainly more well known in the South Island, where they are more common, but they are generally so rare nowadays, that they are almost unknown by most Kiwis. During my field trip last year to Australia, I couldn’t help but notice the huge amounts of mistletoes there, both in terms of sheer numbers and the number of species, even in the driest regions of the Outback: In any given area, at least one tree had a mistletoe growing into it; in some areas, every tree had one, often more massive than the tree itself.

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Like all mistletoes, the New Zealand species are hemi-parasitic. Mistletoe seeds are generally spread by birds, and germinate on host tree branches, often with their own complete portion of fertiliser. From there the seed grows into the branch of the host plant, tapping into the host’s vascular system to get access to sugars, nutrients and water. Over time, the mistletoe will grow and begin to photosynthesise on its own, relying less on the host plant for sugars, and more for its water and nutrient requirements. Like all parasites, mistletoes have negative effects on their hosts, and can severely restrict growth and reproduction. However, they are also recognised as a keystone species in most ecosystems, providing food and nesting sites for a number of animals, particularly birds.

New Zealand has Beech-, Green- Dwarf-Mistletoes. The Beech Mistletoes, as their name suggests, comprise three species (Peraxilla tetrapetala, P. colensoi and Alepis flavida that predominantly parasitise the native southern beech species (Nothofagus spp.), although they are also found on other native species including Tawheowheo (Quintinia serrata) The two Peraxilla species have bright red flowers in Summer, which in older times would turn entire mountain ranges red at Christmas. The Green Mistletoes are perhaps less charismatic but far more generalised than the Beech Mistletoes, and one species, Ileostylus micranthus has been recorded on over 200 host species, including totara and the Pittosporum species.

The main threat to our native mistletoes are possums, which is not unsurprising given the damage that the barstards have done to many of our plants and ecosystems. Mistletoes have declined hugely in range over the last 100 years, and are now entirely absent in many areas where they were previously common. Possums browse the flowers, leaves and shoots of mistletoes, removing vital food source for native birds such as tuis and bellbirds, which in turn act as pollinators for the mistletoes. As a result, not only do the mistletoes disappear, but bird populations also begin to suffer. Many areas that have effective long term possum population control (through 1080 drops) have had remarkable restoration of their mistletoe populations.

Peraxilla tetrapetala
Peraxilla colensoi
Peraxilla tetrapetala on Beech in the Southern Alps.