The importance of grasslands to humanity

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The importance of grasslands to humanity
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Introduction
Over 30 of the land surface of the Earth is
covered in natural grassland and savanna
vegetation dominated by grasses. Grasses are
considered the most important plant family on
earth and grasslands one of the essential
life-support systems on the planet. Despite the
vital role grasslands play, up to 80 of South
Africa's grasslands have been irreversibly
transformed by forestry, agriculture and
development. Less than 2 are being formally
conserved. Southern Africa has more than 976
different grass species, of which 329 are found
nowhere else on earth.
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History
The origin and spread of grasslands in South
Africa have been viewed by early ecologists as
being man-made a sign of environmental
degradation for use in farming and pastoralism
and spread at the expense of forests. Recent
scientific evidence has shown that grasslands
date back long before human impact was of any
significance. A study published in 2000,
investigated soil carbon isotopes taken from the
'ancient' Hluhluwe Forest. The results revealed
that the area was previously grassland dating
back to before the Iron Age.
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Advantages of grassland conservation
Cleaner air
A study in the USA has shown that grasslands in
moist climatic zones such as those of the eastern
region of South Africa store more carbon than
tree communities in those areas. This is contrary
to popular belief that planting of trees would
counter the effect of pollution from factories
and burning of fossil fuels more effectively.
Preserving grasslands can contribute to the
reduction of global warming.
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Water
Studies have shown that grasslands are most
effective in absorbing and directing rainfall
into the water table, collecting rainfall in
catchment areas and reducing run-off. Grasses
bind the topsoil and in many cases are the only
defense against soil erosion and desertification.
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Grassland products
Direct agricultural grassland products
Many grassland species have been domesticated for
use as foodstuffs including

• Wheat
• Oats
• Barley
• Maize
• Sugar
• Sorghum
• Sugar

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Indirect agricultural grassland products
These include

• Sheep and cattle
• Wool
• Milk
• Leather
• Thatching grass, etc

These are basic necessities for nearly all people
on the planet.
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Wild flowers

• Grasslands are home to a host of jewels of the
  plant world including bulbs, orchids, herbs and
  small woody shrubs. Many of these species are
  endemic.
• Grasses may dominate the eye, but the majority of
  species are the wild flowers which outnumber
  grasses by about 32.
• The vast majority of rare plants are the wild
  flowers. These are often confined to localised
  pockets and may stay in those positions for
  decades if not hundreds of years.
• Most wild flowers have built-in chemicals that
  protect them from herbivores and insects. This is
  why a large part of medicinal plants are found in
  grasslands.

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Biodiversity

• The estimated loss of biodiversity today, is a
  thousand times higher that the natural rate of
  extinction.
• One in every eight known plants are threatened
  with extinction.
• This compromises our ability to feed, clothe,
  house and medicate future generations.
• More than 90 of calories consumed by people
  worldwide come from just 80 plant species 80 of
  the world's population still rely on plants for
  medication and 60 of all pharmaceuticals on the
  market are derived from plant or animal products.
  
• Perhaps more importantly ecosystem services such
  as pollination, clean air, water, climate
  regulation, drought and flood control, nutrient
  recycling and soil productivity is something no
  life, including human can exist without.
• annual replacement value of ecosystem goods and
  services in Durban is R 3.1
  billion per annum.

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Economics
Economically natural grasslands make a major
contribution to South Africa's GDP.

• An example The runoff from the grassland
  catchments around Wakkerstroom, Mpumalanga, alone
  supply water to Eskom's Highveld Power Stations
  and the SASOL plant at Secunda with a tap value
  in Johannesburg of more than R 625
  million each year. These power stations provide
  70 of South Africa's electricity requirements.
  Without this water all the coal in the world
  would not be able to provide these requirements.
• Water from the alpine grasslands of Lesotho is
  likely to far exceed this value to the South
  Africa Economy.
• The grasslands of south-eastern Mpumalanga also
  provide free grazing formore than 1,5 million
  sheep. The meat value of these sheep at a
  Johannesburg butcher is more than R 487 million.
  The same sheep provide their owners with an
  annual wool cheque well in excess of R 50
  million.
• The value of grassland species used by
  traditional healers has not been properly
  assessed, but is likely to run to at least
  another R 50 million annually.

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Tourism
Tourism earned South Africa somewhere around R 7
500 million in 1996 and it is the fastest growing
industry in the country, indeed in the world.
While not all of this money was generated by
eco-tourism, Satour's research does show that by
far the majority of tourists were attracted to
this country's natural assets. The International
Union for the Conservation of Nature maintains
that bird watching is by far the biggest sector
of the world eco-tourism market. There are
between 40 and 50 million bird watchers in the
United States and Canada alone and around 28
million of these spend at least a week away from
home each year. Most of these are eager to
increase their world lifelists and are keen
travellers to areas with a high number of endemic
species. With ten endemic species, South
Africa's remaining natural grasslands are bound
to get a large slice of this tourism pie and thus
contribute even further to the country's GDP
provided that these grasslands survive our
onslaught against them.
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Threats to grasslands

• Overutilisation for grazing.
• Too frequent burning, lightning and arson.
• Invasion by alien plants.
• Fragmentation the larger the grassland the more
  viable it is.
• Inappropriate usage such as trail bike or 4x4
  tracks.
• Tree plantations that dry up the water tables and
  shade out natural species.
• Alien trees and water thirsty alien trees such
  as wattle, gum and pine draw water from adjacent
  areas, depriving the area of their water quota
  an effect described as 'water piracy'.

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• Loss of species diversity due to overharvesting
  of medicinal plants.
• Soil erosion caused by poor road siting and
  maintenance.
• Siltation from adjacent croplands can suffocate
  slow-growing species.
• Urban development.
• Certain endemic species are threatened with
  extinction due to the reduction and loss of their
  natural habitat.
• Pollution of habitats by pesticides.
• Extensive commercial afforestation.

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Grassland facts

• The conservation status of grasslands is low,
  relative to forests.
• Southern Africa has more than 24 000
  species of flowering plants - almost 10 of the
  world's flowers concentrated on about 2 of
  earth's land. No other country in Africa can
  match this biodiversity.
• Grasslands are difficult to establish from seed.
  Species are mainly resprouters and although they
  produce seed, they hardly take root.
• Birdwise, 40-odd species are endemic to South
  Africa, Lesotho and Swaziland. Of these 12 are
  endemic to our grasslands.

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The role of Invertebrates
(insects, worms, millipedes, ants, butterflies,
etc)
Invertebrates play a vital role in the
functioning of the grassland ecosystem

• Pollination most plants are
  
  pollinated by insects.
• Herbivory the major herbivores
  are insects.
• Population regulation the major
  parasites and
  predators are invertebrates.
• Decomposition, nutrient cycles, soil structure
  and fertility are maintained mainly by
  earthworms, millipedes, ants and termites,
  together with fungi.
• Food sources as prey to many vertebrates.

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Grasslands in KwaZulu-Natal
"Some 50 years ago there were sheets of Arum
lilies in the spruits and vleis of the Congella
and Pinetown flats, festoons of tree orchids in
the thick bush of Westville and Sarnia, Clivias
and Agapanthus in abundance in the damp krantzes
of Kloof, the Palmiet and the Umhlatunzane
Rivers, the sides of which were clothed in
Maidenhair Fern, Streptocarpus and Begonias.
Entire hillsides white with Marguerites or aflame
with aloes, whilst in many places in the open
grass veld along the coast, on the Harrison
flats, around Pitermaritzburg, Ixopo, Richmond
and Estcourt, right up to the Drakensberg, there
could be seen masses of Ground Orchids, Gladioli,
Cerodendrons, etc where now we may only find an
occasional clump." Mairn M Hulme 28 May 1954.
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Krantzkloof Nature Reserve and surrounds
This area has been described as a botanical
hotspot. The combination of mild temperatures,
high rainfall and acidity of the soil supports
and high diversity of plant species. The area is
also rich in endemic species. The greater Durban
sandstone hills and plateaux and the neighbouring
ones such as Table Mountain and Noodsberg rank
amongst the richest in southern Africa. Given the
very high levels of loss of these grasslands to
agriculture and development, the few remaining
patches have exceptionally high conservation
value. Less than 0,1 is under formal protection
in a nature reserve.
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Aerial picture taken around 1954 shows clearly
that the land adjacent to the Krantzkloof Nature
Reserve was grassland.
Picture courtesy John Field
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Endemic vs Indigenous
The terms endemic and indigenous are often
confused by both scientists and non-scientists.
Indigenous species can be defined as one, which
occurs naturally in the locality it is found.
Endemic on the other hand is a species which
occurs naturally in an area with a restricted
range and found nowhere else in the world.
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Endemic species in and around Krantzkloof Nature
Reserve

• Reptiles and amphibians (info to follow)
• Inverterbrates (Info to follow)

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Wild Flowers
A few examples of endangered endemic plants in
and around Krantzkloof Nature Reserve.
Pictures or drawings have been omitted to avoid
unscrupulous use of wild plants by illegal plant
collectors.

• Brachystelma natalense
• Status Critically endangered very rare
• Brachystelma modestrum
• Status Near threatened rare
• Gladiolus cruentus
• Status Endangered rare
• Dierama pallidum
• Status Vulnerable rare
• Gasteria croucheri
• Status Vulnerable rare

• Geranium ornithopioides
• Status endangered very rare
• Turraea pulchella
• Status Vulnerable very rare (Recently found
  in grasslands adjacent to Krantzkloof and
  incorporated into the reserve for protection)

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KZN Grassland facts

• There are over 30 000 terrestrial species of
  invertebrates in KwaZulu-Natal.
• KwaZulu-Natal has over 6000 different plant
  species - more than three times the number found
  in England - many of them endemic to the region.
• Only 5 of Durban's original vegetation survives
  today and only 2 of it is functionally intact.

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Conservation Guidelines
Corridors

• Grasslands should be linked
• by grassland corridors to
• allow animals, birds and
• butterflies to move between
• them. These are necessary to
• allow
• Genetic exchange
• Dispersal to other suitable areas after a
  disturbance
• To locate alternative food sources and breeding
  sites.

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Forest Grassland Ecotone
Ecotone types between forest patches and a
grassland matrix.
A an abrupt ectone where no transition area is
visible B a gradual ecotone where vegetation
from both biotopes consitutes the transition
area C an ecotone where the vegetation
differs from those of the adjacent biotopes
Source D. Kotze, PhD.1999
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Gradual ecotones

• The transition from grasslands to forested areas
  in an ideal situation would
• include vegetation different from that found in
  either the forest or grassland.
• This would
• Deflect wind over the forest
• Preventing topling of trees
• Penetration of alien plant seeds into the forest
• Preserving moisture content within the forest
• Stop fires burning forest interiors preventing
• destruction of trees
• Destruction of food resources
• Soil erosion
• Alien plant establishment
• Encourage invertebrate species that rely on both
  forest and grasslands for survival.

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Fire management

• Fire is an important management tool and the most
  important
• disturbance in grasslands.
• With regards to wildlife conservation if is
  important to note
• Time of year of burn
• Area of burn
• Fire frequency
• Fire intensity

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Some basic principles

• Maintain grassland corridors.
• Plan cultivation and farm operations to prevent
  aerial and water-borne drift of pesticides.
• Maintain an adequate area of grasslands around
  forests.
• Protect ecotones by burning away from them.
• Burn when most invertebrates in the area are the
  least susceptible to fire.
• Burn to ensure continuity of food sources.
• Leave some areas unburnt as a refuge for
  wildlife.

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Projects
The dedicated people involved in projects like
the Ekangala Grassland Biosphere Reserve hope to
establish and maintain a grassland biosphere
reserve stretching from the high altitude moist
grasslands of Mpumalanga to the Free State and
KwaZulu-Natal a total area of around 1 million
hectares. The target area is home to more than
100 plant, 12 bird, 6 mammal and 2 butterfly
species that are endemic to the area. The
Biosphere Reserve Programme was established under
the auspices of UNESCO (United Nations
Educational, Scientific and Cultural
Organisation) to ensure that Man was brought into
the conservation equation. By 1996 there were 329
internationally recognised Biosphere Reserves in
83 countries (none in South Africa) covering more
than 218 million hectares throughout the world.
South Africa has four biopshere reserves at
present.
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Conclusion
It is clear that grasslands are a valuable asset.
Prompt, preventative action will cost less in the
long run. The destruction of southern African
grasslands is following the same trend as that
which wiped out other primary grasslands in the
world, notable the prairies in North America. We
are fortunate to be in a position to halt the
destruction further, but time is running out
fast. Everyday in KZN a part of our heritage
slips away - townhouse developments bordering the
Hawaan Forest, a new toll Road along the Wild
Coast and over 5000 new townhouses in Hillcrest.
For isolated islands of grasslands to survive, we
need to use indigenous plant material, including
grasses, to create corridors and a refuge for
wildlife to preserve the biodiversity and
ecological functioning of the land and our
natural heritage.
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Acknowledgments
This presentation was compiled by Wendy Moulton
from information provided by Johann Vermeulen,
Officer in Charge, Krantzkloof Nature Reserve AJ
Armstrong, Animal Ecologist, Biodiversity
Division, KZN Wildlife Wally Menne,
Environmentalist Prof Braam Van Wyk, University
of Pretoria Rob Scott-Shaw, KZN Wildlife Jean
Lindsay, Environmentalist John McAllister,
Wakkerstroom Natural Heritage Association
All the photographs in this presentation were
taken on one day in a small area of grassland in
the Krantzkloof Nature Reserve.