Biodiversity

Biological Diversity

Biodiversity is a term used to capture the immense variety of life on our planet. It covers all plants, animals, bacteria, fungi and more, and includes not just microscopic organisms but ecosystems.

“The top five largest threats to our global economy are all environmental, including biodiversity loss.”

The World Economic Forum (WEF) Global Risks Report 2020

From Our Biodiversity
HotSpot To Your Home

Our home, Aotearoa, New Zealand, is one of just 36 biodiversity hotspots in the world. These locations represent 2.3% of Earth’s land surface, but 44% of the world’s plants. Biodiversity hotspots are both biologically rich and deeply threatened. To stem this crisis, we must work to protect them. 

From Our Biodiversity
HotSpot To Your Home

Our home, Aotearoa, New Zealand, is one of just 36 biodiversity hotspots in the world. These locations represent 2.3% of Earth’s land surface, but 44% of the world’s plants. Biodiversity hotspots are both biologically rich and deeply threatened. To stem this crisis, we must work to protect them. 

Beyond CO2;
TAHI Bio
Value Index®

TAHI utilises a toolkit to help us address the dual challenge of global warming and biodiversity loss. One of these is The Bio Value Index® which is an assessment of how much a species contributes to a whole ecosystem. It considers everything from a tree's impact on invertebrates, to intersecting birdlife, tree longevity and carbon storage data. Because nature doesn't operate on a singular metric (CO2) and not all forests are equal.

The ‘bio value’ (BVI®) of a plant species indicates its value to restoring ecosystems. Birds play a pivotal role as seed distributors, a key ecosystem function. They act as primary and are the architects of these ecosystems by transporting seeds around the landscape, so the BVI® is especially weighted towards the attractiveness of a plant species to birds.
Identifying species through tools like the BVI® is one of the keys to the success of the strategic restoration. It is a practical and repeatable methodology that guides the decision-making helping to determine what to plant, where to plant it and the underlying rationale for these choices; What constitutes ‘right’ will differ from place to place, whether in Aotearoa, New Zealand or globally.

This critical information can then be integrated with drone and satellite data, EDNA, DNA, and acoustic recordings alongside traditional grid carbon models; to offer a glimpse into the future of forestry.

The BVI® specifically includes pine as a point of comparison. This is because Pinus radiata is the country's most planted species and currently monopolises a staggering 90% of New Zealand’s carbon market.

This comparison also extends to carbon sequestration, where carbon is absorbed into the new growth of trees. Native trees grow slowly but live longer lives – hence they are very carbon-dense. Pine trees sequester carbon quickly because of the speed of their growth. However, this gradually trails off due to low wood density and its decomposition process. This is why we included longevity as a measure within the BVI®. 
Decomposition is also vital for the carbon cycle. Decomposing trees release carbon, both into the atmosphere and into the soil. Soil acts as a natural reservoir for natural, long-term carbon retention, facilitated by microbes, fungi, and soil structure while enhancing soil health. High carbon density trees, upon decomposing naturally, exhibit a unique trait: because they are carbon-dense, their gradual decay retains a significant portion of carbon within the soil. 

Native species in Aotearoa New Zealand have evolved in isolation for millennia, adapting to the local environment. With 80% endemic to NZ, they develop diverse, extensive, intricate, and interconnected root systems crucial to the health and resilience of an entire ecosystem. These roots play a pivotal role in moisture retention, soil enrichment, and providing support for a diverse range of organisms so the dynamics of diversity and unseen alliances below ground all play a vital role as an extension of their BVI® value.

A Pioneering Approach: The BVI®

1. Longevity as an indicator of length of carbon storage (Extra long >500 yrs; Long 250-500 yrs; Medium 125-250 yrs; Short 60- 125yrs; Very short <60yrs).

2. Carbon content based on wood density (Extremely
high >1000 Kg/m3; Very high 750-1000 Kg/m3;
High 500-750 Kg/m3; Medium 250-500 Kg/m3;
Low <250 Kg/m3).

3. Carbon years index. Multiplied scores of longevity and carbon; longevity on a logarithmic scale, carbon on a linear scale. This is an indicator of how long and how much carbon will be stored.

4. Bird and Invertebrate values indices. The importance
of a species to these two groups. NB in other regions, different/additional groups will be included in
biodiversity quality.

5. Biosphere Value index. Carbon years index and Biodiversity quality index added together and rescaled to a 0-100 scale. The ‘bio value’ (BV®) of a plant species indicates its value to restoring TAHI’s ecosystems. 

6. Pines, provide no nectar or fruit to build or uphold an ecosystem from the ground up.

Plants with High BVI®

Pūriri (Vitex lucens) is one of New Zealand’s most notable keystone tree species. Its flowers, fruits and seeds are a valuable food source for the majority of the year for many species, including the Tūī (Prosthemadera novaeseelandiae), a bird important for ecosystem change. The Pūriri’s dense foliage provides habitat and shelter for a diverse range of wildlife, while its trunk and roots help to nurture the local water and soil system. It is a surprisingly fast-growing tree, which alongside its high wood density, makes it an efficient long-term carbon sink, for perhaps a 1000 years. Its fallen branches and old trunks are also favoured by native Kiwi for nesting and roosting. The myriad benefits it provides for an ecosystem are reflected in its high BVI® value. The Pōhutukawa (Metrosideros excelsa), also has a BVI® value of 100. It fulfils a very similar role to the Pūriri, albeit in an entirely different ecosystem; however, they are not interchangeable. The Pōhutukawa thrives on sea cliffs and coastal landscapes, whereas  Pūriri is found in the more inland ecosystems. The Pōhutukawa thrives on rocky cliff faces overlooking the sea, whereas the Pūriri is suited to inland ecosystems.

This demonstrates just how important it is to understand the characteristics of each tree and its surrounding habitat.
Fig. 1 Pūriri
Fig. 2 Pōhutukawa

Important Plants with
Lower BVI®

As the figure also shows, not every plant in a strategic restoration programme can, or should, have a high BVI®. The Kauri tree (Agathis australis), for example, only has a BVI® of 47. This is because it does not directly support birds and larger species. Nevertheless, as an exceptionally long-lived canopy tree, it helps regulate forest temperature and environment. It also modifies soil conditions and provides support to plant species under its tree canopy, and is therefore invaluable in creating a healthy ecosystem. Consequently, it plays a crucial role in fostering a healthy ecosystem.

Mānuka (Leptospermum scoparium), a prominent pioneer shrub species in Aotearoa New Zealand, provides significant ecological support to invertebrates. Despite its low BVI® of 10, it has an important role to play as part of the rich tapestry of species that together can transform an ecosystem.
Fig. 3 Kauri
Fig. 4 Mānuka

TAHI Biodiversity Highlights

Biodiversity Positive. Carbon Negative.

We change the conversation on carbon, to focus on the potential of biodiversity restoration to stem the dual crises of global warming and biodiversity loss.

Bird Life: From 20 to 71 Species

In 2004, when our restoration project began, TAHI was home to 20 native species. Today, we have 71 and counting, including 25 rare and endangered birds.

8.8 Million Native Trees Planted or Regenerated

At TAHI we have unlocked the regenerative power of natural ecosystems. Birdlife super-powers our strategic planting, acting as natural architects for our ecosystem.

100% Profits Reinvested into Biodiversity

TAHI’s model sees us develop global brands with biodiversity at their core. We invest 100% of the proceeds from TAHI brands into biodiversity projects.

20 Wetlands Re-Established

Wetlands act as the kidneys of the land. We are proud to have restored almost all of the original wetlands: 96 acres of wetlands and 11.1 acres of lakes to date.

Biodiversity Positive. Carbon Negative

We change the conversation on carbon, to focus on the potential of biodiversity restoration to stem the dual crises of global warming and biodiversity loss.

Bird Life:
From 20 to 71 Species

In 2004, when our restoration project began, TAHI was home to 20 native species. Today, we have 71 and counting, including 25 rare and endangered birds.

8.4 Million Native Trees Planted or Regenerated

At TAHI we have unlocked the regenerative power of
natural ecosystems. Birdlife super-powers our strategic planting, acting as natural architects for our ecosystem.

100% Profits
Reinvested

TAHI’s model sees us develop global brands with biodiversity at their core. We invest 100% of the proceeds
from TAHI brands into biodiversity projects.

20 Wetlands
Re-Established

Wetlands act as the kidneys of the land. We are proud to have restored almost all of the original wetlands: 95.6 acres of wetlands and 11.1 acres of lakes to date.

20 Wetlands Re-Established

Wetlands act as the kidneys of the land. We are proud to have restored almost all of the original wetlands: 96 acres of wetlands and 11.1 acres of lakes to date.

100% Profits Reinvested into Biodiversity

TAHI’s model sees us develop global brands with biodiversity at their core. We invest 100% of the proceeds from TAHI brands into biodiversity projects.

8.8 Million Native Trees Planted or Regenerated

At TAHI we have unlocked the regenerative power of natural ecosystems. Birdlife super-powers our strategic planting, acting as natural architects for our ecosystem.

Bird Life: From 20 to 71 Species

In 2004, when our restoration project began, TAHI was home to 20 native species. Today, we have 71 and counting, including 25 rare and endangered birds.

Biodiversity Positive. Carbon Negative.

We change the conversation on carbon, to focus on the potential of biodiversity restoration to stem the dual crises of global warming and biodiversity loss.
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Carbon & Biodiversity

Global warming and biodiversity loss are two of the biggest crises facing our planet. While intrinsically linked, these two pressing issues are largely considered independently. However, they are global, interconnected problems.