Every summer the Department of Conservation in Wanganui, and various other conservancies, helps to organise a summer nature programme. These usually include various trips to unusual, or normally inaccessible, places. One trip that is quite popular in the Wanganui conservancy is to the Kaimanawa ranges, near Waiuru. The land we visit is crown-land used by the Army as a training ground. It is mostly high altitude tussock country with some beech and other forest communities.

For a botanist, or an aspiring botanist like me, access to the Kaimanawa's is a real treat because the area has a very high plant diversity and is usually closed to the public. However, the area is very contentious because it also hosts wild horses. About two or three years ago, this issue became so inflamed that the government of the day intervened.

The problem is as follows; there are a large number of rare or endangered plants in the Kaimanawa's, some only occur there and nowhere else in the world. Most of these plants are very small, and hard to find, and terribly unexciting to the uninitiated. These tiny plants tend to occur in nutrient poor, swampy areas. The same areas that the wild horses prefer because the grasses grow faster there, and because during the summer water is scarce.

There are 12 horses in this photo, and 9 of them are grazing in the swampy area around the stream, and this is under the current low horse densities. The horses trample the rare plants, introduce excess nutrients (horseshit) and change the waterflow with their trampling.

Grazing by horses has also virtually eliminated some plants, such as a species of tussock, and opened up the ground for invasive weeds such a hawkweed (Hieracium).

To protect the plants DoC decided that the horses' numbers should be reduced, so that the most vulnerable areas are horse free, and maintain lower numbers in the remaining areas. This became quite contentious because many people love the horses (I like horses too) and did not want to see any reduction in numbers.

In the end it came down to the fact that the rare plants are more endangered than the horses. There is more information on the Kaimanawa horse issue on the DoC pages.

Apparently, the horses look a lot healthier now than before. There is more food to go around, and less fighting between family groups to secure a grazing area.

The plants are really neat there though, but I did feel guilty when we ventured into one of the wetland areas. Even us lighter Homo sapiens leave pugholes in those fragile habitats.

There were three species of carnivorous plants. I only have pictures of two of them, because I didn't know what I was looking at when I spotted the bladderwort (Utricularia monanthos), and had no time to go back.

All these plants are really small. The Drosera spathulata plant above is only about 2 cm in diameter. The leaves of the Drosera stenopetala (shown left) are about 4 cm long. Both of these Drosera catch small insects in the sweet sticky droplets excuded from the hairs that line the leaf edges. When an insect is caught in the sticky sap the hairs curl over to hold the insect even more tightly and then start to digest them. This is an adaptation to get more nutrients in an environment that has very few.

The bladderwort catches insects in a slightly different way. It floats in the bog, and produces little nooses underwater. Any insect that swims into a noose will cause it to close and trap themselves. Pretty ingenious he? All these carnivorous plants hate extra fertiliser, so horse manure is a definite no.

This plant is great too. It is called a bidibid and is a bur that will stick to your socks. Initially as a ball, but it quickly disintegrates into hundreds of individual hooked seeds. The picture shows a hybrid between an Australian and a New Zealand species. The New Zealand species is bright red (yes they really are that colour) but the burs have virtually no stalks. The ones in the photo do have stalks so they must have hybridised with an Australian invader.

This is one of the many native daisies, Celmisia. The plant is about 50 cm tall, one of the larger species, and has these beautiful large white daisies.

We also saw one of my favourite orchids Gastrodia cunninghammii that I talked about in one of the Tangarakau episodes. And beautifully flowering Peraxilla tetrapetela. It was pretty amazing to see that flowering outside of the cages that protect it from possum browsing. That shows that possum control in the area is successful.

All in all, I had a great day, lots of really interesting species to see (most of which are impossible to takes photos of) and CO and WF there to point them out to me and the other day-trippers. The tussocks were in full bloom, and it is also a masting year.

Masting means that the species has irregular episodes of heavy flowering, and this is a heavy flowering year. The masting hasn't been confined to just the tussocks, flax (Phormium species), cabbage tree (Cordyline species), kiekie (Freycineta banksii) , beech trees (Nothofagus species), tawa (Beilschiemdia tawa), Coprosma species and a whole range more have done exceptionally well this year. The only species notable for their unspectacular flowering year were pohutakawa (Metrosideros excelsa) and the large tree rata's (M. robusta and M. umbellata). Ah well, maybe next year it is their turn.