Biodiversity discussion
A landholders duty of care in terms of maintaining biodiversity
by Leon Ashby

Below is a discussion starting point for trying to working out landholder's
duty of care in terms of biodiversity. Please send in your criticisms so
landholders around Australia can have confidence that this issue has been
given considerable thought.
(If it`s too heavy just go to the summary).  

Why do we need a clear understanding of Landholders "duty of care" towards
the land?

There is
(1) The constant pressure by many environmental groups wanting controls on
land management across Australia.
(2) The perception created by the negative publicity around Australia`s tree
clearing, salinity and water debates that has politicians jumping to do
something "green" to capture the so called green vote.
(3) Legislation such as the Commonwealth Environmenal Protection and
Biodiversity Conservation act (EPBC) that now has to face up to "Just terms"
(4) Landholders demanding a National Property rights bill which will set the
basis for dealing with what happens when property rights (such as being able
to change vegetation) are removed
If Just terms for a loss of management rights is defined, then there is a
need to define what is landholders responsible to keep the land in good
shape, and then any conservation responsibilities (that the community deems
necessary) above the duty of care level  would be the public`s
responsibility. This will be important so that the public knows what it will
have to pay for.

In the past there have been statements by governments on the issue of  
ecologically sustainable development  (ESD), that is development that will
not cause problems to overall biodiversity.

Here are some quotes on ESD

While there is no universally accepted definition of ESD, in 1990 the
Commonwealth Government suggested the following definition for ESD in

'using, conserving and enhancing the community's resources so that ecological
processes, on which life depends, are maintained, and the total quality of
life, now and in the future, can be increased'.
Put more simply, ESD is development which aims to meet the needs of
Australians today, while conserving our ecosystems for the benefit of future
generations. To do this, we need to develop ways of using those environmental
resources which form the basis of our economy in a way which maintains and,
where possible, improves their range, variety and quality. At the same time
we need to utilise those resources to develop industry and generate
The World Commission on the Environment and Development (1987) said it like

"development that meets the needs of the present without compromising the
ability of future generations to meet their own needs"
The Council of Australian Governments (1992) said it like this

ESD  aims to meet the needs of Australians today while conserving our
ecosystems for the benefit of future generations.

It then said in the third of three parts

To protect biological diversity and maintain essential processes and life
support systems

All these definitions are similar but not exactly the same, but I believe the
principles are that the Australian community should be
(a) keeping all species,
(b) maintaining essential processes and
(c) maintaining life support systems

 I do not think anyone would disagree with that.

 It appears that our society should then
(A) Set some goals for land management (e.g. how much of our land should be
(i) wildlife conservation,
(ii) vegetation conservation
(iii) primary production, &
(iiii) cities and industry etc

(B) Define landholders duty of care towards the land used for primary
production and

(C) Uphold property rights with just terms options to landholders whose
managerial rights have been removed.

Duty of care to the land will no doubt have several parts to it
(1) A salinity responsibility
(2) An erosion responsibility
(3) A pollution responsibility and
(4) A biodiversity responsibility

The main point of contention is in regards to the biodiversity responsibility.

I would expect that Landholders would
(a) Accept that it is their responsibilty to produce food and fibre in a way
that keeps the land functioning, essential processes functioning, and life
support systems functioning.

(b) Expect other lands (govt, public, private city etc) which are not
occupied by buildings or roads, to share these responsibilities of functions,
and no group or individual (e.g. govt, ) should be exempt.

(c) Expect that all non voluntary conservation - whether it`s an endangered
species or not, to be a public good and therefore has to be paid for by the

Now let`s take the issue of "duty of care for Biodiversity" To do this
requires some more detailed knowledge of how ecosystems operate.

The following information is based on the University Text book "Environmental
Science" by Botkin & Keller 1998. This is a brief explanation.

* No organism lives on its own accord. All species eat and use other
organisms or parts of their products or wastes.  An ecosystem is the cycle of
species that exist off each other and supply each other with essential
resources for survival.

* All the elements required for life (carbon, water, nitrogen, phosphorus
etc) have to cycle as well .
(You have probably seen diagrams of food chains and food webs and carbon
cycles and water cycles which convey this understanding.)

Competing species, and niches

To get a handle on how all the species interact in an ecosystem is not easy
as every interaction has various factors involved, so here are some basic
concepts to mix up together.

* Two species with exactly the same requirements cannot coexist in exactly
the same habitat (e.g. rabbits and Australia`s small mammals)  

* Species that require the same resources can coexist by utilizing those
resources under different environmental conditions. That is they can have
different niches (e.g. two flatworm species have slightly different
temperature ranges in a stream. When species A is on it`s own it is found
from 6 to 17 degrees. When species B is on it`s own it is found at 6 to 23
degrees. But when found together A occupies temperatures 6 to 14 degrees and
B temperatures 14 to 23 degrees.)

* Some species are symbiotic, that is they help each other (e.g. bacteria in
our intestines that help digestion and ourselves providing a place for them
to live)

* And some species have a predatory / parasitic relationship (e.g. grazers
and grasses)

Factors that increase diversity are

* The more diverse habitat allows more niches and more species exist.
* moderate disturbance (fire, storms etc)
* small variations in environmental conditions (soil type, temp, moisture etc)
* High diversity of one Trophic level (e.g. trees) increases diversity of
another trophic level (e.g. birds) - (A trophic level is the number of food
chain steps from the primary source of energy e.g. plants are on the first
level, grasshoppers the second and birds who eat grasshoppers the third
trophic level.)
* Environment highly modified by life (e.g. rich organic soil)
*Middle stages of succession

Factors that tend to decrease diversity are

* Environmental stress
* Extreme environments (e.g. very hot or very cold)
*Severe limits to essential resource (e.g. water, nutrients)
*Extreme amounts of disturbance
* Recent introduction of exotic species
*Geographic isolation

But what about ecological services redundancy?

Dr Henry Zuill  a professor of Biology at Lincoln college Nebraska (USA) has
written the following paragraphs

 An interesting phenomenon in ecosystems is ecological services redundancy.
i.e. - A service provided by one species may also be provided by other

Highly biodiverse communities are more stable, more productive, have higher
soil fertility, and are generally better off.
Under stress, however individual species populations may noticably vary in
size but fortunately redundant services appear to cover for immediate lacks.

This means that a service provided by one species may also be provided by
other species.

Research reveals that above a certain level of plant biodiversity, soil
fertility or productivity did not increase , even when biodiversity continued
to increase.

Ecosystems are dynamic. They can stand a certain amount of abuse without
ecological collapse. When one species become extinct, (in that ecosystem, but
not necessarily the world) a few other species , but not all species (in that
ecosystem) become extinct.

Redundant systems prevent mass extermination.

Species move into  ecosystems when they can. Some species may not be found
because they are not locally available.   On the other hand , certain
propagules or offspring may not germinate , grow or survive because necessary
ecological services may not be available . When provided with these essential
services, however, those species would be able to move into the ecosystem.
The dynamic nature of ecosystems provides for making use of what species are
available and able to function.

Biodiversity, redundancy and resiliency permit an ecosystem to recover from
severe damage and even ecosystem destruction. When this happens, the recovery
is stepwise and may take a number of years. The process is called "ecological

Does that mean that ecosystems can be renewed or started from scratch?

Dr Patrick Moore, a founder of Greenpeace says this

Forests are resilient. They can grow back from total volcanic destruction,
ice ages, fires, storms, whatever. You can take heavy equipment and bulldoze
the soil right down to bedrock over a huge area, and if you go away and come
back 100 years later you will have a new forest starting to grow back. Just
logging the trees is not going to irreversibly destroy the ecosystem. In
addition, I believe it is possible to sustain the biodiversity of a forest
while removing large quantities of timber.

But that is in a humid environment - what about the arid desert type areas?

There are a growing number of landholders worldwide who are regenerating
their land in desertifying areas, and will possibly make it more productive
than it ever was in recent history.

Allan Savory has shown how to regenerate land in these areas (some
desertified by inappropriate grazing and other areas that have been mined and
have no topsoil). All had little soil life. Some places could not even grow
plants when seeds were just watered and fertilised. These areas can
eventually become a vibrant diverse landscape by introducing fodder (carbon /
energy) and animals (cattle) on to the area. After the stock have trampled
the fodder and spread urine and dung around, the land is rested until some
plants have grown after sufficient rain and are ready for grazing. The cycle
of short grazing periods and appropriate resting (depending on the plants
being grown) is begun and the plants, and soil life which feeds on the
trampled fodder and dung etc continue to establish and build a soil with life
in it.  

As Dr Henry Zuill says "It appears that life on earth makes life on earth

Ultimately this means that provided we preserve every species somewhere, then
we can regenerate  or begin any type of useful or needed ecosystem.

Now the big question - what is a Landholders duty of care concerning

From what Dr Zuill has written it could be argued that since it is a
landholders interest to maximise production, then it is his responsibility to
achieve a level of biodiversity that maximises production and this should be
his level of biodiversity duty of care.

It could be also argued that to exceed that level of biodiversity is not his
responsibility as it does not increase the ecological services that are
already being performed in providing maximum production.

But what is it that keeps an ecosystem functioning - what is it`s bottom line?

There is a popular perception the answer to this question is - we need every
species that is in an ecosytem to be conserved to keep ecosystems functioning.

I will suggest that answer is not correct. Due to the fact that many species
can perform the functions of other species, and no one can dictate exactly
which mix of species will stay in an ecosystem, (some species outcompete or
exclude other species) I believe the correct answer to what keeps an
ecosystem functioning should be
 what keeps as much biodiversity as is necessary for all the essentail
functions to be performed.

And the answer to that is sufficient water and energy flow.

A way of understanding this is considering two different approaches to having
a pet refuge. One pet refuge operator says what he needs is lots of pets to
be successful (while he forgets about their food and water needs) , so he
concentrates on getting every creature he can in his refuge. The other says
lots of food, water and comfortable living conditions, are the basis and the
pets will turn up soon afterwards. Which pet refuge is going to be more

So I am saying that provided the land is not continually poisoned, and there
is sufficient water and energy (organic matter) then the mix of species
available will interact to provide for each others needs. In other words
biodiversity will take care of itself if moisture and organic matter in the
soil are sufficient and they continually cycle (flow).

You keep mentioning Energy Flow - What does that mean?

Energy Flow is the movement of energy through an ecosystem. All life requires
energy.  It starts when energy is converted from sunlight to energy available
for other life forms to use (organic matter).  As each animal life form uses
the energy (carbon) for it`s own use and expires carbon dioxide etc back into
the atomosphere the flow continues full circle. To sustain life in an
ecosystem means the Energy flow should be maintained. But if we want
healthier land and more humans living off that ecosystem, then the energy
flow will have to increase.

So again what I am saying is the best way to sustain and conserve life is to  
increase plant production, use those plants, in some ways directly, and in
some ways to feed other life forms, which will increase the opportunity for
many more life forms to survive and so on and so on .  It`s actually growing
more food for the biodiversity to live off, which then grows more food again

But that sounds different to what many conservationist`s say?

Yes, this is a vastly different view to the "conserve it but don`t use it"
thinking that  has captured our society. A view that saves everything, but in
doing so prevents the essential cycles (e.g. carbon, water ) from increasing.
Currently in our national parks in brittle environments, the energy flow  is
decreasing (i.e. grasses are being grazed less, so organic matter does not go
back into the soil as much) and as a result soil biodiversity will gradually
decrease in volume therefore the survival of some species may become

While critics of this position  will say It is arguing for a "use till it
collapses" strategy, I will say that the focus should be on the energy and
moisture made available for the majority of our worlds biodiversity, which is
in the soil. This is what we should set our sights on and everything else
will follow.
If we concentrate on any non basic issues only  E.G. farming methods, or
species conservation, or regulations, or limiting water etc without focussing
on the soil carbon and moisture levels, then we will ultimately go backwards.

But what about native tree retention rates, we cannot ignore them can we?

Once we recognise the need for water and energy flow as the basis for
sustainability, the next thing to consider is what goals do we want in our

We would all agree on minimising erosion, salinity, & pollution, but native
species and biodiversity wise there will be debate. For example if the goal
of our land use is to grow crops sustainably, then what level of tree
retention assisting biodiversity is essential for crops?
This would depending on how the cropping is achieved. so lets say it is by a
method that maintains organic matter at 3% of the top soil (a good level for
Australian soils). There would be plenty of soil life to grow healthy crops.

Will any extra biodiversity via retained native vegetation and dead timber
improve production?  
That I cannot tell you, but if research was done which showed a certain
amount of native tree retention helped improve crop production, then whatever
that vegetation level is could be argued to be the necessary retention rate.

Similarly with grazing woodlands. We should look at areas where pure
grasslands with high organic matter and soil biodiversity are and compare
these with similar areas with the added biodiversity in native vegetation and
other species until we find the retention rate which maximises production.  
These sorts of Questions are now being asked.

Gretchen Daily from Stanford University (USA) said on ABC radio`s Earthbeat
recently "when you have an animal pollinator you get a higher yield and
higher profit for farmers.We’re just undertaking the studies now to determine
what are the trade-offs for a farmer if he or she were to allocate a bit more
land to pollinate our habitat - how would they see their profits change?"

Now if anyone were to argue that landholders should have to retain more
biodiversity (trees and other vegetation) than that which provides for
maximum production, then It could be argued that they are being forced to
conserve  biodiversity for the public good and of course that should be paid
for by the public.

But what about retaining native vegetation for other reasons?

There are other reasons for vegetation retention and landholders will retain
trees and vegetation for other purposes than simply the biodiversity to
sustain life.
E.G. Native and exotic trees for shelter, voluntary wildlife habitat
conservation, milling timber, firewood, and any other  goals landholders
have, but none of those issues would be classified as for sustaining
essential processes or maintaining life support systems.

Do you have any clues what sort of vegetation retention rate we are talking
about could be likely for (1) just maintaining a rangeland ecosystem  and (2)
maintaining a rangeland ecosystem at maximum production?

There are many places in the world which are almost treeless grasslands, and
have been for thousands of years. These include the North American Prairies,
the Steppes of Eurasia, the plains of eastern and southern Africa, and the
Mitchell Grass Downs of Australia (which is gradually getting some trees on
it now).

If we ask what amount of native tree retention rate is required in these
areas for just sustaining an ecosystem (not necessarily at maximum grass
production) - my guess is maybe only one percent or even zero.

If we were to then ask what amount of tree retention rate was needed to
sustain ecosystem services for these grasslands to produce at their maximum,
we might get a different, higher value.

These places seem to me to be where some research could be done to see if
grass production increased the nearer one came to timbered vegetation and
what sort of improved ecosystem services were being provided by these
timbered areas. (e.g.extra insect / animal pollination)

Certainly it would be difficult to negate other factors affecting
productivity, but maybe it could be done, other wise the amount of native
vegetation retention required for sustaining essential processes to get
maximum production could remain a contentious issue.

In Summary

By understanding the way that species interact between each other including
the fact that a service provided by one species may also be provided by other
species. means there is amazing robustness in ecosystems.

Ecosystems can be restored even from total destruction.

The most important needs for ecosystems is water and energy flow (cycling
organic matter)

By increasing organic matter to a certain level (with sufficient moisture) in
the soil, biodiversity can naturally increase and reach an optimum level
where production can be maximised. To improve soil organic matter until that
level is achieved could be argued to be one part of a landholders duty of

The open grasslands of the world demonstrate trees are either not essential
or only a very minimal amount is needed in maintaining  ecosystem processes
and sustaining life support systems in the rangelands.

 If it is decided that as part of the biodiversity duty of care, vegetation
retention rates should be the level that can accomodate maximum productivity,
then unless there is broad agreement on a designated value, some research
should be done to decide this level.

 landholders may have other landscape goals (voluntary wildlife refuge areas,
milling timber, firewood, shelter etc) which may add to this basic vegetation
retention level, but none of these should be considered as essential
biodiversity requirements.