Stories written in the whenua beneath our feet. Geoheritage, geoconservation and geoeducation.

It's hard to believe it is March already, and we can hardly call it the beginning of the year anymore. Welcome to our first post for 2019, and I look forward to many more this year. A huge thank you to all my supporters, subscribers, followers, and guest writers who have inspired to keep this blog active. I look forward to bringing you many more posts along with some great new guest writers lined up for this year.

One of the things that kept me busy towards the end of last year was making a presentation on a subject that encompasses many of the fields that I am interested in, that can be broadly defined under the umbrella of "geoheritage". It is because of the disciplines related to this field such as  archaeology, history, Earth sciences, and ecology that I find myself increasingly referring to myself as a "cultural geologist". 

The author contemplates a 150,000 year story of erosion,
underwater landslides, shifting continents, and massive tectonic 
forces shaping this spectacular outcrop at Otarawairere, 
Eastern Bay of Plenty. Source: Phil Pollock (2018).

This post draws on many ideas made in a presentation to  the New Zealand Geosciences Society 2018 conference. I would like to acknowledge the efforts of Bruce Hayward in organising the geoheritage symposium, and extending the invitation to present. 

Financial support to attend the conference was provided by Te Papa National Services Te Paerangi, and ongoing support by the organisation for promoting this kaupapa is apprecaited. You can follow and support the organisation on their facebook page by following the link below

Finally, I would like to acknowledge my colleagues and co-authors, Chris Twemlow (Landmapping.nz), and Karoly Nemeth (Professor in Geology of Massey University).

Due to my background in Earth Sciences, I have largely been introduced to ideas related to geoheritage through the geological and Earth Sciences community. Often I am asked to explain geoheritage, and I stress the broad interpretation of the prefix "geo" as Earth, and in a more local sense the place where we stand. I am increasingly coming to see the importance of this kaupapa to the tourism, conservation, and education services. I also see an important role for the museum and heritage sector in promoting and facilitating geoheritage and geotourism ventures. While the traditional role for this sector may be viewed as collection and conservation of physical taonga, I suggest involvement by museums in collaboration with other community organisations such as libraries and local heritage societies, encourages a view of our cultural landscapes and associated geosites as a taonga in their own right.

One challenge for tourism today stems from the fact that most people’s knowledge of New Zealand prior to visiting may be limited to a series of well-publicised, extremely popular, and well utilised tourist hot-spots. We describe this as the must-see paradigm, where the tourist experience of New Zealand is limited to an itinerary based on a series of stand-alone experiences interspersed with periods of travel between destinations. This approach has seen increasing congestion at tourist hot-spots, increasing strain on infrastructure, and competing interests between local residents and visitors.  

Trampers await transport at the Katetahi Road end of the
Tongariro Crossing. This one-day walk is considered one of the 
countries top tourist destinations, seeing increasing congestion 
and strain on infrastructure in one of New Zealand's few
World Heritage Areas.
Source: Kathy Ombler (2017). Retrieved
from Wildernessmag.co.nz 

 

Beachgoers and hazard warning signs at Cathedral Cove,
Coromandel. Source: www.gns.cri.co.nz (2018).

Coromandel Peninsula is widely promoted for its white-sand
beaches, set against the backdrop of a relict volcanic 
landscape. However, little mainstream promotion seeks to educate or 
enlighten regarding the geological and cultural story of this landscape.
Source: http://www.coromandelfun.co.nz/ (2018).

The term geoheritage recognises the fact that a landscape and its people have a story to tell in the ongoing history of the community which can be told through sustainable tourism and education initiatives. Geological, cultural, and ecological features with effective interpretation can be used to provide an engaging and dynamic learning experience for visitors, educators and all community members. Providing a visitor experience that integrates the natural history of the land with the cultural and human history provides a highly valued visitor experience of local, regional, and international significance. A successful example of such a venture is the Māngere Mountain Education Centre, situated on the lower slopes of Te Pane o Mataoho - Māngere Mountain. Modeled on the concept of a living museum, here one can "walk the present, discover the past". 

Panel explaining the relationship between terraces
visible on the side of Māngere Mountain and pre-European'
Earthworks, indicating the importance of this site as a large 
pā situated on an extinct volcano at the centre of a network of
smaller villages and gardening complexes on the ring-plain formed 
by lava and ash deposits from the volcano. The carved figure 
acknowledges the importance of this area to tangata whenua, and
a landscape that physically connnects them to their ancestors.
Māngere Mountain Education Centre, South Auckland. 
Source: Ian Lawlor (2015).

Interpretation at Troopers Hill Local Nature Reserve, Bristol UK. Clear,
engaging, and well laid out information integrates information on geology
and environment. Source: http://www.troopers-hill.org.uk (2018).

Interpretation panel at Ihumātao fossil forest, Māngere, South Auckland.
Engaging visible material with an engaging scientifically accurate story
tells the story of landscape changes due to climate change, rising sea-levels
and catastrophic phreatomagamtic volcanism. Source: Author (2016).

Here in the Eastern Bay we are blessed with a rich cultural heritage and archaeological history. When we first think of our heritage, we more than likely think of buildings or structures that have an obvious and explicit connection to our past. However, human history in this country stretching back centuries has left a rich and dynamic story written in the landscape around us. 

Looking across a terraced ridge-line at Onekawa Te Mawhai Regional
Park towards Whakaari - White Island. Terraces are the imprint left
on our landscape by pre-European defensive earth-works. Source: Author (2018).

Cliff-top shell midden exposed by erosion of coastal cliff-top
at Waiotahe, Eastern bay of Plenty. The round group of stones
visible towards the top of the shells are hangi stones (a type of oven using 
heated and buried rocks). This demonstrates the desirability
of these locations due to the nearby marine resources, and the easily
defendable cliff-top terraces. Source: Author (2017).

Illustration showing Māori defensive earthworks and timber pallisades.
Interpretation panel at Tauwhare Pā Scenic Reserve, Ōhope, 
Eastern Bay of Plenty. Source: Author (2018).

The rolling hills, ridges, and natural terraces of the Eastern Bay made ideal pā sites, while valleys were home to extensive floodplains and wetlands. Rivers and smaller streams provided abundant resources as well as an extensive transport network.  This was especially the case in the lands surrounding Ōhiwa Harbour, one of the most densely populated areas of the country prior to European settlement.  The Eastern Bay was a highly desirable area to settle, no doubt for many of the same reasons people continue to be attracted to the area today. 

Distribution of pā sites in the Bay of Plenty. High density
of sites can be seen in the Tauranga region and between 
Whakatāne and Ōpōtiki. Source: Archaeology of the Bay of
Plenty, by Garry Law, Published by the Department of
Conservation (2008).

While this may be common knowledge amongst tangata whenua, it was not until the mid 20th century that the extent of pre-European population and settlement became apparent to archaeological researchers and historians. In an early site survey by local historian and farmer David White, 200 pā sites were estimated to be present in an area from approximately 12 miles east to 12 miles west of Ōpōtiki. Since then work has continued researching, mapping, and excavating archaeological sites, confirming the extensive and complex networks of whanau and hapu that resided in this area. As technology and methods for research and surveying continually improve, we find there is still a wealth of knowledge and history to be gained from exploration of our whenua.

Unfortunately, throughout New Zealand culturally significant sites have suffered many ravages, despite protection through legislation, and the Bay of Plenty is no different. Quarrying has destroyed maunga and pā sites, roads and tracks have beeen driven through and over the top of archaeological sites and urupa, and agricultural development has all but obscured the rich layers of history preserved within our whenua. In addition, our archaeological heritage, which to a large degree is represented by sites and landscapes of significance to tangata whenua, is poorly protected protected by legislation through the Heritage New Zealand Pouhere Taonga Act (HNZPT) 2014.  

Often the only Archaeological record we are left with of significant sites is through a process colloquially referred to as  "rescue archaeology". Due to requirements of the HNZPT and the Resource Management Act, permission to modify or destroy a site or feature may be granted if an archaeologist is present, and a record is kept of any findings. This process particularly favours private land-owners and developers, whose primary interest is the tangible returns form economic development, rather than the intangible gains of cultural preservation. This is reflected in comments below from the recently published article "The Mounting Crisis at Ihumaatao"

"Established in 2014, HNZPT is charged with ensuring the ‘identification, protection,  preservation,  and  conservation  of  .  .  .  historical  and  cultural  heritage’ However, up to March 2017, it granted almost 97 percent (877 of 907) of applications for developments affecting Māori archaeological sites.HNZPT claims pre-application discussions can result in protective measures, but the Ihumaatao decision suggests the HNZPT Act 2014 almost exclusively favours  private  property  rights  and  developer  interests  over  protecting  the  values and benefits of our oldest cultural heritage places."  Source: The Mounting Crisis at Ihumaatao: A High Cost Special housing Area or a Cultural Heritage Landscape for Future Generations? (2018). By Tim McCreanor, Fances Hancock, and Nicola Short. Published in Counterfutures No 6. Full article available here.


Despite the poor record of protection and preservation, when we look around us we can see the imprint on the land of a highly organised and culturally rich society taking advantage of topography and supported by rich resources of the land and estuaries. High points with extensive views over the Ōhiwa harbour and coastline were the sites of regionally important pā sites, where human made earthworks can still be recognised by the terraces we see left behind today. Onekawa Te Mawhai Regional Park is the site of five closely neighbouring pā sites, now thankfully preserved and protected from further damage within the park. A vigorous walk up the steeply sloping track from the entrance at Bryan's Beach takes one past several exposed shell middens and standing on the flattened top of the Onekawa pā site one gets a sense of how important this site would have been in observing movements in and out of the harbour, of both friendly and hostile visitors to the area. 

Above and Below: Onekawa Pā is situated at a high
point on the Ōhiwa Headland, providing extensive views
over the Ōhiwa Harbour entrance, and east towards
Cape Runaway. Source: Author (2018).

Beneath the vegetation one can get glimpses of the history
of this dynamic landscape, both  human and geological. Here
one can see layers of ash, pumice, and other sediments exposed
in an outcrop beneath exposed pōhutukawa roots. Onekawa
Te Mawhai  Regional Park. Source: Author (2018).

  

In time vegetation and soil will cover evidence of human
occupation, but erosion may also work to expose it.
Here a shell midden can be seen exposed by erosion on a 
steep bank at Onekawa Te Mawhai Regional Park. 
Source: Author (2018).

Archaeological excavations at sites elsewhere on the coastal margin of the Ōhiwa harbour have recovered material including obsidian scrapers from Great Barrier and Mayor Islands; greywacke from Motutapu (Auckland); basalt from the Tahunga quarry in Coromandel; and argillite from D’Urville Island. Evidence shows that the earliest settlers on the Ōhiwa Harbour arrived over 700 years ago, during the period described as the “archaic” or “moa-hunter” period. The archaic period pre-dates 1500AD, while the period post 1500AD saw the development of Māori society and culture as encountered by the first European explorers.

Abundant marine resources would have sustained both a local population, as well as providing a significant regional resource. The fertile ash and pumice cloaked hills and terraces with their fertile free-draining soils were ideal for cultivating crops. The harbour itself would have been an important shelter and waka landing place on an exposed coastline with few sheltered harbours in the immediate vicinity. The diversity of stone artefacts recovered from this area provide evidence of extensive, country-wide trading networks. 

In researching the history, geology, and cultural landscapes of the Eastern Bay of Plenty, I would like to acknowledge Whakatōhea Research and Archives Trust, Upokorehe kaumatua, Lynda Walter (archaeologist), and Tanja Rother (researcher and writer). 

The Ōhiwa Harbour Heritage trail provides a great opportunity to explore our environmental and cultural heritage. The first stage of the trail, featuring a number of sites focusing on the environment was implemented last year, with development of a further number of sites currently underway, bringing alive the cultural history of the area.

Interpretation panel exploring the bird-life one may see at points on the Ōhiwa Harbour Heritage Trail.
Source: Tanja Rother (2018).

 For a downloadable copy of the Ōhiwa Harbour Heritage Trail brochure follow this link

Coming up from 27th April until 5th May is the New Zealand Archaeological Association Archaeology Week 2019. This year Ōpōtiki Museum, will be hosting several events, while a guided walk on Sunday the 28th of April will take in Onekawa and Te Mawhai Regional Park, and several nearby sites on the harbour edge. For more information go to the Ōpōtiki Museum website or Friends of Ōpōtiki Museum facebook page. Also keep an eye on your local media for venues, times, and other updates.



 

A very merry Metrosideros excelsa. Our chiefly Pōhutukawa.

Summer has well and truly arrived here in the Eastern Bay, with our beautiful sandy beaches attracting visitors from near and wide. Our beaches are even more special for their backdrop of large stately pōhutukawa trees (Metrosideros excelsa) bursting into a profusion of crimson flowers. This tree holds an important part in our culture, with Māori regarding it as a chiefly tree (rākau rangatira) and the blossom refered to as kahika.

A profusion of crimson flowers against the deep green 
of a tree fern at Ōhope Scenic Reserve. Source: Author (2018).

While we may take these beautiful trees somewhat for granted as part of our natural environment, it is in fact not as common as it once was in coastal areas of the upper North Island. Once pōhutukawa, and several species of rātā, could be found in a continuous coastal strip as far south as Poverty Bay on the east coast, and Northern Taranaki on the west coast. These populations have been reduced to a few isolated stands and relict individuals, with our local Eastern Bay population an important environmental taonga and significant population. 

Mature pōhutukawa have a distinctive rounded and spreading canopy,
seen here adjacent to dunes at Waiotahe Beach, Eastern Bay of
Plenty. This would have once been a common sight
all along the east and west coasts of the top half of the 
North Island. Source: Author (2018).

Pōhutukawa is adapted to coastal conditions, where the largest and healthiest specimens are usually found, with deep and tenacious roots allowing it to colonise rocky outcrops and coastal cliffs. It is also commonly seen colonising bare ground such as landslips and lava fields where it can use its roots to extract hard-to-reach nutrients and water.  The sturdy and massive roots and trunks of these trees are reflected in the name of the genera Metrosideros, meaning “iron-hearted”. Other species in the genus are rātā, and together these species belong to the Myrtaceae (myrtle) family, which includes manuka, kanuka, eucalyptus, and Callistemon (Bottlebrush) species. The species name of pōhutukawa, excelsa, refers to its outstanding or sublime, appearance when in flower.  

The bright and showy flowers of the pōhutukawa smother the canopy at this
time of the year, providing a signal to pollinators that nectar is available. Tokitoki
Historic Reserve, Ōhiwa Harbour. Source: Author (2018).

The especially hard wood was highly valued for boat building, as its nature made it particularly suitable for curved pieces required for the structural frame of boats. Where older wooden boats have used pōhutukawa for the structure, and kauri for planking, the pōhutukawa have often been found to be more durable and longer surviving than the kauri.

However, it is undoubtably the spectacular flowers of these trees that now hold such a special place in our hearts, both for their distinctive crimson colour, and the fact that the pōhutukawa flowering heralds our summer and a time of festivities and relaxation. It is the smothering of bright crimson flowers reaching their peak in mid-December that have seen the pōhutukawa affectionately referred to as the New Zealand Christmas Tree. 

Bright red flowers are highly visible, and their placement at the top of the
canopy of trees mean they can be seen from afar by potential
pollinators. Source: Author (2018).

Flowers are also highly valued by our native and non-native nectar-feeding birds, attracted by the nectar at the base of the flowers, thereby pollinating the flowers, and ensuring seed becomes fertile. A more modern pollinator taking full advantage of the offerings of the pōhutukawa flower is the introduced honey-bee.

Flowers are a type known as “brush blossoms”, formed by a mass of bright red stamen with a shallow bowl of nectar at their base. Masses of flowers displayed at the canopy of the trees attract birds from a distance, and seeking nectar, they pollinate the flowers by transferring pollen from the male stamen to the female stigma. While our most well known species of pōhutukawa is the crimson flowered variety, there is a yellow flowered sub-species 'Aurea'. All yellow pōhutukawa have their provenance in a pair discovered on Motiti Island in the Bay of Plenty. While Māori were aware of these yellow blossomed trees, they were botanically described by Norman Potts, the renowned amateur botanist from Ōpōtiki. Regional variations in flower colour and growth habit have been taken advantage of in the development of many cultivars such as a pink variety 'Pink Lady', and white variety 'White Caps'.

Detail of flowers, formed by a mass of crimson stamen tipped with pollen.
Clearly visible at the base of stamen are the circular nectar cups, attracting
pollinators who do the job of transferring pollen from the male stamen to the 
female stigma. Mahy Reserve, Ōhope. Source: Author (2018).

Detail of yellow flowered pōhutukawa. Nectar cups are also clearly 
visible in this flower at the base of the clusters of male stamen forming
the most visible part of the flower. Māngere Bridge, South Auckland.
Source: Author (2018).

Fertilised seeds develop in an ovary at the base of the stigma, in time forming a seed capsule that spreads its numerous wind-borne seeds in winter. Tiny wind-borne seeds are ideally suited to gaining a hold in rocky cracks and crevices where enough nutrients have accumulated to nurture the growing seedling. 

Where nothing else will grow a pōhutukawa seed lodges in a crevice and 
takes advantage of dust and soil collecting in the cracks of this sheared and
weathered greywacke,  providing nutrients for the tenacious seedling. 
Whakatāne Heads. Source: Author (2018).

Over time a pōhutukawa is able to send its roots exploring 
cracks and joints in weathering rock, driving it apart and 
finding nutrients and freshwater to support the tree making 
the most of this inhospitable environment. Otarawiarere,
Whakatāne. Source: Author (2018).

It is due to the wind-borne nature of these seeds that the trees are often be found colonising rocky off-shore islands, such as Rangitoto in the Hauraki Gulf, and Whakaari/White Island in the Bay of Plenty. Some of the best examples of relatively undisturbed pōhutukawa forest can be found on these offshore islands, with Rangitoto the largest Pōhutukawa forest in the country. Pōhutukawa is able to establish relatively quickly on bare lava-fields, meaning it is easily able to pass the threshold from colonising species to dominant canopy species.

Twisted and gnarled pōhutukawa trees with an understory
of ferns form a scene typical of a small fragment of pōhutukawa forest
surviving on Whakaari/White Island, despite the toxic atmosphere
and frequent eruptions. Source: Ralph Ward, date unknown. Retrieved 
from: tauranga.kete.net.nz (2018).

Here in the Eastern Bay, at Ōhōpe Scenic Reserve, one can experience one of the last remaining mainland stands of mature pōhutukawa and rewarewa dominated bush, still intact largely thanks to the tireless work of volunteers undertaking pest control. Possums heavily browse on spring vegetation, as well as mature vegetation, and if left unchecked they can lead to a premature death of trees that should be able to live to a thousand years at least. Pōhutukawa dominated forest is distinctive for criss-crossing and branching trunks of the trees. 

Vertical branches and trunks criss-cross with near-horizontal branches,
forming a pattern typical of mature pohutukawa forest, or stands of mature regenerated 
or planted pōhutukawa trees. These trees give the stretch of State Highway 2
between Ōhiwa and Ōpōtiki it's name of Pōhutukawa Drive. Source: Author (2018).

In open spaces such as reserves and parks, where pōhutukawa is a popular amenity species, trunks can grow thick, twisted and convoluted. A prime example of this is Mahy reserve in Ōhope, where trees can also be seen festooned with thick mats of distinctive aerial roots typical of mature trees.

Above and Below: Gnarled and twisted trunks of pōhutukawa
at Mahy Reserve, Ōhope. Over time aerial roots may reach
the ground and form parts of the trunk. Source: Author (2018).

Detail from above showing dense thicket of
interwoven aerial roots, typically found on mature trees.
Source: Author (2018).

The East Cape is also famous for what is reputed to be the largest pōhutukawa in the country. Te Araroa is home to a tree known as Te Waha O Rerekohu “The mouth of Rerekohu”. This is certainly the largest pōhutukawa in the country and may well be the oldest at over 400 years. 

Above and Below: Te Waha o Rerekohu, said to be the largest and the oldest pōhutukawa in the world. 
Te Araroa, Gisborne District. Source: Murray Dawson (2106). Retrieved from inaturalist.nz

So, as you enjoy the coming summer days against a backdrop of crimson flowers, clear blue skies, and glistening white sands, take a moment to appreciate this special taonga we are blessed to have amongst us. If you would like to find out more about the ecology, culture, and history of the Metrosideros species, check your local library for “Pōhutukawa and Rātā. New Zealand’s Iron-Hearted Trees” by Philip Simpson.

Reference for this post has also been made to the journal article "Biological flora of New Zealand 14: Metrosideros excelsa,pōhutukawa, New Zealand Christmas tree", by RJ Bylsma, BD Clarkson, and JT Efford. To read the full journal article link here.

Finally, I would like to thank the Whakatāne Beacon and Eastern Bay Life for supporting this column over the last year, and supporters and followers of this blog. I look forward to more exploration of our unique and dynamic Eastern Bay of Plenty and hope you will join me in 2019.  Merri Kirihemiti!