Otago Daily Times Comment "Over the Fence" · High Country Grazing Effects not Quite so Straightforward 17 June 2013

04/09/2013 at 22:15 in Otago Daily Times

Last month’s ODT articles on Birchwood station highlight the gap in New Zealand land management knowledge, an issue Kim Hill explored on her radio show with Allan Savory early June.  Savory would be one of the world’s most controversial wildlife biologists because he promotes livestock to restore landscape vitality; the complete opposite of what the rest of the world believes. 

What conservation and agriculture fail to comprehend is what Savory calls brittleness, how annual distribution of soil surface moisture influences outcomes of land management tools.  Brittle environments experience highly seasonal or very erratic rainfall, what we typically refer to as desert like environments. 

Non-brittle environments experience regular rainfall and by definition all environments must fit on a continuum between these extremes.  Behaviour of these environments is further complicated by altitude, e.g alpine verses coastal. 

Brittleness influences the outcome of any tool applied in an environment; overgrazing on the West Coast creates a tight dense sward and seldom does a soil surface stay bare for long.  Do the same thing in the high country and bare soil quickly establishes and remains; landscape function goes backwards.

Savory falls into no-man’s land and is chastised by all parties.  Agriculturalists think his ideas silly because modern technologies enhance landscapes faster.  Conservationists think them ludicrous because as everyone knows livestock causes land problems and the only way to fix situations is to leave it to nature; removing livestock and resting land is the only tool for restoring biodiversity. 

The high country’s climate intensifies issues of land degradation.  Anybody driving south through the Lindis Pass can see what locking up land does to its function; bare soil seals over increasing moisture runoff leading to eventually declining biodiversity.  This scene is repeated in livestock exclusion plots on high country stations. 

There is nothing wrong leaving nature to do its thing if it creates the landscape wanted.  If eroding tussock lands or invasive grass species dominating tussock lands as seen elsewhere in the South Island is desirable, then leaving to nature is fine.  But in many cases this is not the outcome desired from the original intent locking away such sites from livestock. 

This situation arises from the deep public perception that biodiversity can only be restored by “leaving it to nature” because humans can only destroy environments, as human civilisations have demonstrated for more than 10,000 years.  Livestock exclusions plots also prove this in the high country in years immediately after their installation. 

Yet decades later these same plots exhibit the opposite.  Funding for most scientific research lasts no more than three years so it’s farmers who fund the same professionals years later.  However, policy is grounded on the immediate research even decades old because it wasn’t funded by vested interests.  This is where professionals mistake a research event for a trend.  What options are left to mediate such situations?

Savory argues there must be a change at the soil surface for ecological shift to occur.  In farming we do this by either herbiciding pasture or turning soil over, or both.  The terrain of the high country makes applying technology expensive and often risky.  The only other tool is fire which removes carbon into the atmosphere, cooks soil biology, exposes soil, and if done regularly creates fire dependent communities as seen in Australia. So what are benefits of livestock?

According to Savory livestock bring two tools to the table; grazing and animal impact.  Grazing is the removal of vegetation allowing light to get to growing points of plants which are located near the soil surface.  This is why vegetation found on road verges is different than over fences in paddocks; seldom does sunlight shine on soil surfaces so only species which can handle this circumstance survive. 

Animal Impact includes everything else livestock bring such as dunging and urinating, trampling, and rubbing for example.  These impacts are most controversial because they create a mess. Yet this evidence of disturbance is essential to invigorate ecosystems.  It is the recovery time between such events which has the greatest influence on ecosystem resilience and stability, whether on farm or elsewhere.

The depositing of dung and urine allows the ruminant digestive system to substitute soil biology by partially decomposing what is eaten.  Trampling when done properly pushes dead grass on to soil surfaces allowing it to wick up moisture to decompose.  Both these activities speed up cycling of nutrients and soil development by covering soil and protecting an unpaid and unseen workforce of soil biology underneath. 

It’s not the tool but how it is managed which is overlooked.  Few professionals understand how livestock enhance soil structure, patterns of biodiversity, water absorption and holding capacity, and fertility.  Such knowledge combined with proactive monitoring would provide alternative solutions to high country conservation issues. 

John King is a Christchurch based agribusiness tutor, facilitator, speaker, and grazing advocate.

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