Monoculture serves precisely one master. That of the heavy equipment
used to plant and harvest it. That this approach is highly
vulnerable is no surprise. What we have to do now is to think
through methods in which we can blend diversity into our growing
regimes along with that critical diversity.
We have posted on the application of arboreal banding of crop fields.
This envisages narrow tree lines set wide enough apart for two
passes of the harvesting equipment. Since the actual tree line
itself will be well lit, they can be pruned high and an understory
can also be planted and managed along with wild ground cover. This
is easily contained by tilling equipment. The strip width can be
rather narrow although a greater that minimal width is likely
indicated.
Orchard dwarf trees are possible although they can make equipment
passage difficult. I suspect that specific species tailored to this
environment will emerge. Again a treeline benefits from extensive
side lighting. For that reason everything planted within the
treeline can be optimized for commercial productivity.
For instance, it is easy to plant two walnut trees well apart to
provide an upper story and then plant perhaps three apple trees or
cherry trees in between for a middle story. For ground plantings,
any number of fruiting bushes are available also leaving again enough
space for diverse local weeds and grass on the ground. My point is
that it can be very productive if it is then actively maintained and
this takes some human effort at least.
These types of treelines can take up perhaps as much as ten percent
of the crop land which may well not impact final yields at all
because of natural fertilization and other positive impacts.
In the meantime this is merely my starting point and it shows us what
is possible. I even found a way to apply it in Saskatchewan and that
surely means that it can work anywhere.
Biodiversity helps
protect nature against human impacts
by Staff Writers
Guelph, Canada (SPX) Feb 15, 2013
"You don't know
what you've got 'til it's collapsed." That's how University of
Guelph integrative biologists might recast a line from an iconic folk
tune for their new research paper warning about the perils of
ecosystem breakdown.
Their research,
published as the cover story in Nature, suggests farmers and resource
managers should not rely on seemingly stable but vulnerable
single-crop monocultures. Instead they should encourage more kinds of
plants in fields and woods as a buffer against sudden ecosystem
disturbance.
Based on a 10-year
study, their paper also lends scientific weight to esthetic and moral
arguments for maintaining species biodiversity.
The study was written
by Profs. Andrew MacDougall and Kevin McCann, graduate student
Gabriel Gellner and Roy Turkington, a botany professor and member of
the Biodiversity Research Centre at the University of British
Columbia.
Their research
confirms that having lots of species in an area helps ecosystems
avoid irreversible collapse after human disturbances such as climate
change or pest invasion.
"Species are more
important than we think," said MacDougall. "We need to
protect biodiversity."
Unlike other
scientists usually relying on short-term, artificial study plots, the
researchers studied long-standing pasture grasslands on southern
Vancouver Island for 10 years. The 10-hectare site owned by the
Nature Conservancy of Canada consists of oak savannah where fires
have been suppressed for about 150 years.
The team selectively
burned plots to compare areas of mostly grasses with areas of mixed
grasses and diverse native plants.
They found that
seemingly stable grassland plots collapsed in one growing season
and were subsequently invaded by trees. More diverse sites resisted
woody plant invasion.
Diversity also
affected fire itself. More diverse areas had less persistent
ground litter, making high-intensity fires less likely to recur than
in single-species grasslands with more litter serving as fuel.
MacDougall said the
study supports resource management strategies that increase
biodiversity on land and in aquatic ecosystems. A monoculture
stand of trees or crops might appear stable and productive, for
example -- but it's an ecosystem that is more vulnerable to collapse,
he said, adding that this study helps explain why species
diversity matters.
McCann, who studies
food webs and ecosystem stability, said many ecosystems are at a
"tipping point," including grasslands that may easily
become either woodlands or deserts.
"They're a really
productive ecosystem that produces year in and year out and seems
stable and then suddenly a major perturbation happens, and all of
that biodiversity that was lost earlier is important now," said
McCann.
MacDougall has studied
the Vancouver Island site since 2000. European settlers planted
grasslands there in the mid-1800s.
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