Recently I have referred to the fragmentation of lowland plant communities. The tiny remnants of forest and wetland remaining on the Waikato Lowlands are often separated by large areas of farmland.

Once upon a time our native plants grew close enough to others of their own species to be able to act . . . → Read More: A Sensible Solution]]>

Recently I have referred to the fragmentation of lowland plant communities. The tiny remnants of forest and wetland remaining on the Waikato Lowlands are often separated by large areas of farmland.

Once upon a time our native plants grew close enough to others of their own species to be able to act as stepping stones for pollen and seeds. This meant that they were able to disperse more effectively across the landscape. Now days pollen is much more likely to fertilize a close relative and plants are isolated from their own species. The long term effects of this are not yet clear but we can expect a loss of diversity and barriers to plants migrating as the climate changes.

To avoid these long term effects “stepping stones” will have to be created where native plants can grow, be pollinated and set seed or spores which can disperse from one stepping stone to the next. If the plants are well ecosourced this will help protect the distinctive local character of plants in this area. Of course, planting areas of native species is expensive, takes up land and  requires maintenance.

Already, big areas of native plants are being planted around new roading developments. Designing these plantings to reflect natural patterns and enhance natural processes  would cost no more; in other words, plant not just  a collection of native plants but plant genuine native forests and wetlands.

If you travel in Britain or Europe cultural heritage is evident everywhere. Castles, churches, bridges and cottages are a really appreciated part of their heritage. Here in New Zealand we have a unique natural heritage which deserves the same value placed on it as the cultural heritage has in the old world.

Biodiversity is a really useful term but it is so often misunderstood that it is sometimes avoided and that is a shame.

Biodiversity is a contraction of biological diversity and came into common usage in the mid 1980s. The term refers to the global diversity of life, the variety of ecosystems, species and . . . → Read More: Biodiversity]]>

Biodiversity is a really useful term but it is so often misunderstood that it is sometimes avoided and that is a shame.

Biodiversity is a contraction of biological diversity and came into common usage in the mid 1980s. The term refers to the global diversity of life, the variety of ecosystems, species and genetic diversity of species. Currently biodiversity is diminishing at an almost unprecedented rate because of human impacts.

Biodiversity can only be increased through evolution which is notoriously slow. We can however reduce or slow the loss of biodiversity by protecting native species in their natural habitat.

A really dramatic example of what can happen is Kawau Island in the Hauraki Gulf. In the nineteenth century all kinds of exotic plants and animals, including zebra, wallabies, kookaburra, parrots and other birds, were released there in a kind of zoo park.
I guess at that time there was no understanding of how an ecosystem works so those involved can’t be blamed. Introducing all of these did nothing to increase biodiversity since all these species were secure in their own natural habitat, but it was devastating for the natural plants and animals on Kawau which have mostly disappeared.

Every plant and animal and, for that matter, micro-organism has its own natural range. Genetic variations within species can be even more localized. Natural ecosystems are made up of life forms which have adapted to each other and fit together a bit like a jigsaw puzzle. So there is a strong connection between location and biodiversity.

That is why at Forest Flora we are really careful to record the location of every seed line we collect and we do our best to copy natural dispersal as closely as possible when we prepare planting plans and provide plants.

By increasing the natural populations of plants and improving natural habitats, we can do our part to prevent the loss of localized biodiversity.

He stuffed a pheasant but instead of displaying it on the mantelpiece he put . . . → Read More: The Real Thing]]> When he was a teenager, like so many kiwi kids growing up on farms, my uncle had a brief flirtation with taxidermy. He wrote away to the Northwestern School of Taxidermy in Omaha, Nebraska and enrolled in a correspondence course.

He stuffed a pheasant but instead of displaying it on the mantelpiece he put it in the paddock just within shotgun range of the garden fence.

Over lunch, my grandad spied the pheasant and without a word, made for the back door. As his right hand extracted two homeloads from his cartridge belt hanging on a nail on the door, his left hand closed around the barrels of his prized Webbley and Scott side by side, standing in its usual place by the door. Grandad crept silently down the path and screened by the dunny, checked to see if the magnificent cock bird was still there.

Now the rules of engagement for pheasant shooting require the bird to be in flight before it is shot, but my grandad had lived through a depression and two world wars. He was more a pragmatist than a purist.

Grandad released first the right barrel then in quick succession, the left one, then as the feathers slowly floated to the ground, he slowly lowered the gun. My uncle had no doubt the look on the old mans face was worth every bit of it and grandad swore ‘till the day he died that he saw the bird jump just before he fired.

Grandad was convinced it was a live cock pheasant but it was just an illusion, a façade. Gardening is a lot like taxidermy. Don’t get me wrong, I like both but they are superficial compared with the real thing. Ecological restoration is about restoring the unseen processes which make an ecosystem work not just an illusion of nature. It takes a little more to set up but there is no comparison between the two.

Removing weeds is only half the story. Unless an environment where weeds can’t grow is created, they will eventually return and we are committed to an eternity of . . . → Read More: Planting to Create an Environment Inhospitable to Weeds.]]> I led a workshop on planting to manage weeds recently for the Hamilton City Council Gully Restoration Programme.
This is a summary of what was covered:

Removing weeds is only half the story. Unless an environment where weeds can’t grow is created, they will eventually return and we are committed to an eternity of weed control.

There are exceptions, but most weeds are adapted to thrive in disturbed areas. That is they grow quickly, disperse effectively and require high levels of light. Natural ecosystems arrange plant species together like a jigsaw, leaving little light available for weeds. Recreating the kind of ecosystem naturally found on the site can be the best way to ensure that little light is available and weeds can’t return.

Every land environment is unique and hosts a unique assemblage of plants. Getting a good idea of what plant species they are is the first step to creating a healthy ecosystem.

That is why we created the Forestflora web site: www.forestflora.co.nz

Some councils around the country have also put together excellent guides to the unique flora of their natural areas.

Every plant species operates in a different way to all others. That is they each have a unique range of tolerances and vulnerabilities. They also modify the environment in a unique way. We can simplify this by dividing plants into three main groups:

1. Canopy trees. These grow tall and create shade over a wide area, but take time to achieve this.
2. Understory. These are specialists in using the remaining light not captured by the canopy trees. They are also specialists in their particular habitat and need to be chosen carefully to get the best plants for each site. Examples from a Hamilton gully include kawakawa, kanono, putaputaweta, Coprosma rotundifolia, C.rigida, hangehange, patete.
3. Colonisers. These tolerate a wide range of conditions, grow quickly, disperse well but need plenty of light and can be short lived. Examples from a Hamilton gully include karamu, ti kouka, kanuka, harakeke

There is one other group: Those plants which form a ground cover, perch up in trees or climb over other trees. These make a valuable contribution to soaking up light but are more often planted once the others are established.

At Forest Flora we have a systematic approach to designing a restoration planting. Starting with those species we know will tolerate the amount of exposure found at each site.

1. Place the canopy trees, each chosen for it’s suitability for the site. Kahikatea and matai on the lower slopes. Totara higher, pukatea shaded, sheltered and damp etc. Tanekaha and rimu on well drained sites
2. Understory species can be less tolerant of wind and frost. Each site is different. Locate those understory species which will tolerate the amount of exposure conditions found on the site on optimal topography and soil conditions for each species. Kotukutuku, putaputaweta, kanono and patete on damp soil, kawakawa, rangiora and heketara on well drained and sheltered sites. A large range will grow well on sheltered sites like the lower slopes of the hills and along the river where the frosts are less severe. Out on the plains and around the peat lakes where frosts are heavier plants adapted to these conditions must be used and others added as shelter develops.
3. The colonisers will provide shelter from wind and frost as well as shade to control weed regrowth until the canopy trees establish. These fill in all the gaps. The more open the site the more colonisers are required. The more weed prone the site, the sooner a canopy must be established so more colonisers are required and planting is at closer spacing.

Those species which we know are found naturally in the area but require shelter can be added gradually as the forest develops. Good preparation prior to planting is essential but with the appropriate matrix of species we can be confident that in the long term our native forest will overcome the weeds. Careful planning may seem like a lot of bother but can save a lot more bother from lost plants and ongoing weed control.

In the area . . . → Read More: The New Forest]]> We have a really interesting job on at the moment. Most of our projects are along rivers and around lakes. Mostly in areas of retired pasture or weedy areas. This area has fifty to one hundred year old totara trees and all the privet and wandering dew has been well removed.

In the area of several hectares of totara there are a few tanekaha (Phyllocladus trichomanoides).
The understory is almost completely bare except for a few of the tree ferns:

ponga Cyathea dealbata, mamaku Cyathea Medullaris        and wheki Dicksonia squarrosa

Remaining native shrubs include; two Coprosma rigida, one poataniwha Melicope simplex, one mapou Myrsine australis and a few mahoe Melicytus ramiflorus. There are also a few climbing ferns: Pyrrosia eleagnifolia.

This is such a rewarding project because the canopy is well established. We can now concentrate on the understory, using the few species remaining as a template and visiting nearby fragments to get a better idea of the species to be expected here.

Because there were serious weeds on the site despite the tall canopy, it is obvious that an understory is needed to help out compete and prevent the return of weeds. I guess the weeds like African club moss (Selaginella kraussiana) and wandering dew (Tradescantia fluminensis) can always reinvade so they will have to be watched carefully.

We made up a list of the understory species we might expect to find in this forest and have collected and propagated seed from nearby sites.

We have been planting shrubs but also spreading ground covers like nertera and acaena, herbs like parataniwha  and climbers like akatea, kohia and kaihua. We will have a few ferns and hope that the others will come in time.

We have already discovered that a tall healthy forest is very resilient to weeds. This is a great opportunity to show what can be done.

This area was the site of gold mining in the nineteenth century and became a spa resort in the twentieth. The forest that once clad the mountain is badly degraded with weeds well established . . . → Read More: Gradients, Timelines and Continuums.]]> I was asked a while ago to plan the restoration of forest on Whakapipi (Bald Spur) in Te Aroha.

This area was the site of gold mining in the nineteenth century and became a spa resort in the twentieth. The forest that once clad the mountain is badly degraded with weeds well established since the gold mining days but there are still clues to the nature of the original forest.  

Climbing up the mine road from the car park the forest canopy gradually looses puriri and eventually kohekohe, with hinau and pukatea  becoming more prevalent and tawa dominating. Kauri are concentrated on the leached soils of some ridges and have their own suite of associated species.

Near the top of the mountain there is a lower stature forest dominated by tawari, Quintinia, neinei, red and silver beech.

There aren’t good examples of the forest of the plains nearby but we might expect a forest dominated by kahikatea with matai, pokaka, pukatea and some titoki and tawa. Puriri might be found depending on the frost levels but kohekohe prefers the  slopes. The understory out there is more likely to include putaputaweta, Coprosma rigida and C.rotundifolia, turepo, Gahnia xanthocarpa  carex species and  Astelia grandis

It is also useful to look back over time to see what records there of the primeval vegetation. Ecological surveys by the Forest Service were updated in 1971, the Te Aroha News published a book for the 50th Jubilee of the town in 1930 including botanical notes and there is a botanical survey of the mountain published in 1884.
Unfortunately the lower slopes are not covered in the Forest Service notes, which refer only to the tawa forest above Bald Spur.

The Adams 1884 botanical survey focuses also on the upper slopes. Possibly because at that time the vegetation of the mountain footslopes differed little from that found all along the range and was much more common than the unique flora near the summit.

It is only now that we realise that this narrow strip of low altitude forest is a vanishing ecosystem and in need of preservation or restoration.

We do have some notes on an excursion to the summit published in 1930 for the town’s fiftieth jubilee. The account mentions from Bald Spur; karapapa, rewarewa, rangiora, titoki, kowhai, hangehange, mahoe, wineberry, tutu, kawakawa and peperonia. The peperonia suggests a mild coastal climate, the tutu and wineberry are generally found in disturbed sites, which gives us some idea of the condition of the area at that time.

What we don’t have is an account from AD1000 or even 1840. 
To get a better idea of the natural vegetation of Bald Spur I followed the walk from Tui Mine Road south along to the Domain. There are fragments of more intact native forest along this walk. I know that further north along the base of the range karaka becomes more common and taraire, and pohutokawa appear but here the canopy is dominated by puriri with kohekohe titoki and tawa. In the gullies the understory is characterised by species like mahoe, kawakawa, hangehange, kanono, putaputaweta pigeonwood, mamaku and ponga. There are scramblers like kiekie and supplejack.  Where there has been disturbance there is patete and makomako. Tanekaha and rewarewa appear where light and drainage is better. Under these are found rangiora, heketara, shining karamu, Coprosma rhamnoidies and lancewood. Metrosideros fulgens, in flower at the moment is a common climber. Kanuka forms the canopy where there has been disturbance in the past.

So by looking up the mountain, down onto the plains, back in time and along the range I have been able to get a better idea of the unique mix of plants for that site.

I was lucky to have so much information available but on all projects the principle is the same, I just have to work harder to find the clues. It would be a terrible shame to plant up all projects with the same species all over the country.