Biodiversity

Biodiversity is the variety of living organisms and the genetic variation in a region including below our feet. Most people only consider the things we can see, feel and touch as significant and mostly ignore that which is in the soil. In a 2011 survey, it was estimated that there were 8.7 million species in the world while only 1.2 million have been formally described. In relation to livestock grazing, biodiversity refers to the woodlands, native scrub, trees, shrubs and native grasses, as well as the animals, insects and microbiology that call this environment home. The rural industries strive to manage the environment in a manner that not only co-exists along-side rich biodiversity, but also helps biodiversity to thrive.

How many living creatures are there in the world?

In a 2011 survey the following numbers were estimated to be found in the world.

• Animals: 7.77 million (12% described)
• Fungi: 0.61 million (7% described)
• Plants: 0.30 million (70% described)
• Protozoa: 0.04 million (22% described)
• Chromists: 0.03 million (50% described)

Farmers Role

Farmers and graziers livelihoods and success are intimately linked to the health of the land and so depend on healthy ecosystems to provide a myriad of services. These include - soil health, nutrient cycling, waste recycling, pollination from insects, sediment control and clean water. Some of the threats to biodiversity include climate change, invasive species (weeds, animals and diseases), loss/degradation of habitat, unsustainable use of natural resources, changes to the aquatic environment and poorly managed fire regimes. Every creature is reliant on other lower order lifeform for their survival (food) – this is the “web of life”. If we remove one part of the web, we end up with major a catastrophe, such as weed outbreaks or the cane toad.

In developing a BMP, we need to consider the impact an action may have on all groups of living organisms within that system as often the smallest creatures may have the biggest effect. In managing the grazing and farming of land, this includes:

• Living below ground - in the soil, (microbiology and macrofauna)
• Living on ground – vegetation (native and introduced)
• Living on ground – animals (native and introduced)
• Living in the air – birds (native and introduced)
• Living in water – terrestrial and marine

Environmental sustainability will require farmers to continue to manage biodiversity issues, enhance critical intact habitats, restore ecological function to critically degraded landscapes through sustainable practices; increase cover of native vegetation to enhance ecological connectivity across fragmented landscapes and build local knowledge and capacity for long-term stewardship of the environment.

Agricultural Census figures

2005-06 Agricultural Census figures reported in 2005, 7% of Australia’s farmers had collectively fenced off 1.3 million ha of degraded or saline land areas, trees and shrubs, creeks and rivers, and remnant vegetation with 35,800 kilometres of new fencing to protect these areas from grazing. In the same period, 4.2 million trees and shrubs were planted for nature conservation purposes as well as 6.3 million trees for the protection of land and water areas.

A BIODIVERSITY BMP

All of these individual creatures from microbial life-forms to the bovine animals (cows and sheep) have an impact on the system whether positive or negative to the ecosystem. A BMP for managing biodiversity is to design activities that will have the least impact on the existing biodiversity within that ecosystem. Many farm biodiversity monitoring programs use birds as an example of measuring impact.

• That is when native bird species declines, then the actions have been negative to ecosystem health.
• Another comparison was carried out using species of ants and macro-fauna to assess the impact of one grazing system to another. 

 Soils

Overall soils contain the greatest reservoir of biodiversity on earth, and the functionality of the soil ecosystem sustains the rest of life on land (terrestrial biosphere). Soil microbes and plant roots micro-engineer their habitats by changing the porosity and glueing properties of the soil pores and aggregates. Microbes also create a habitat that allows or disallows other creatures from thriving or dying in that soil.

Plants

About 7,000 species of plants have been cultivated for consumption in human history. The great diversity of varieties resulting from human and ecosystem interaction guaranteed food for the survival and development of human populations throughout the world in spite of pests, diseases, climate fluctuations, droughts and other unexpected environmental events.
Presently, only about 30 crops provide 95% of human food energy needs, four of which (rice, wheat, maize and potato) are responsible for more than 60% of our energy intake. Due to the dependency on this relatively small number of crops for global food security, it will be crucial to maintain a high genetic diversity within these crops to deal with increasing environmental stress and to provide farmers and researchers with opportunities to breed for crops that can be cultivated under unfavourable conditions, such as drought, salinity, flooding, poor soils and extreme temperatures.
We rely on plants for food, and a blight that targets a major crop could have serious implications. Unfortunately, the world's major staple crops have been greatly homogenized over the years, and that's not a good thing. Many countries have lost agrobiodiversity.

Dung Beetles

Dung beetle

Lots of balls rolled by the ball roller dung beetles (Sisyphus Spinipes).

Ball rollers leave their balls beside posts, stumps and grass tussocks.

Dung Beetles Australia website

Birds - to ensure biodiversity

The Birds Australia guidelines include:

• Local native vegetation should cover at least 30% of the total farm area.
• Maintain shrub cover over at least one third of the area within a patch of farm trees.
• Re-create local conditions
• Maintain a range of tree ages.
• Maintain vegetation around water.
• Exclude high impact land-uses from at least 30% of the farm area.
• Maintain native pastures where possible and avoid overgrazing
• Native vegetation cover should be in patches of at least 10 ha and linked by strips at least 50m wide.
• Manage at least 10% of the farm area for wildlife.
• Leave fallen trees to break down naturally.

The Birds Australia survey conducted pre – 2000 developed several examples. Some of the examples, which support these guidelines, are:

• Bird diversity declines in patches smaller than 10 ha.
• For every 10% increase in tree cover, bird diversity increased by 7% and exotic birds decreased by 21 percent.
• Woodland dependant birds were 12% more diverse in broad strips over 50m of native vegetation.
• Woodland dependant birds were 21% more diverse in farm sites where trees had regenerated naturally than where trees had been planted.
• Total bird diversity declined by 25% in areas where the ground cover had been removed.
• Bird diversity, especially ground foraging birds, was lower in farm sites to which fertiliser was applied in the past 5 years.
• A critical age for planted trees appears to be 5-10 years, after which diversity of birds is significantly greater.
• Noisy Miners were 78% less likely to occur where understorey shrubs were present.
• A river or creek line resulted in a 21% increase in the diversity of woodland dependant birds.
• Bird diversity increased by 3% with each additional dam.
• Small birds were 28% more diverse and ground nesters were 29% more diverse when waterways were present.

Corridors and strips

• Shade lines for stock
• Wildlife corridors for transit of wildlife for habitat and food.
• Linkages between water sources
• Linkages to larger clumps

The shade line or corridor has several extremely important aspects that assist in creation of a microclimate. The vegetation will affect the incidence of extreme hot and cold conditions in the proximity of the vegetated area. It will assist in the cycling of deep nutrients to the top or higher profile. It can assist in the breeding up of predators to manage much of our insect population.

Micro-climate effects

The retention of strips of trees in otherwise cleared grazing paddocks substantially affected the surrounding microclimate.  At Dukes Plains, maximum temperature beneath strips of brigalow trees was on average 4.5oC lower than the open paddock.  The difference was greater when the temperature in the open was above 35oC, being on average 7.2oC cooler in the shelterbelts.

Biodiversity on Farms from Victoria

An increasing number of studies are showing the benefits of wildlife and remnant vegetation.

These are examples of some of the findings from these studies:

• Between 40-60% of crows and ravens diet consists of insects including pasture cockchafers.
• Sugar gliders eat massive amounts of insects. Where enough winter food (mainly from wattles) is available, they will eat up to 18 000 scarab beetles per hectare per season. These insects may be tree defoliators, and their larvae pasture root eaters.
• Owls, hawks and eagles help control animal pests such as mice, rats, hares and rabbits.
• A study suggests that in healthy eucalypt woodlands, birds eat about half of the insects produced annually.
• Sheltered pastures lose 12 mm of water less than open pastures during the spring growing season.
• Sheltered areas have increases up to 17% (estimated) in dairy milk production and 20% (estimated) in average annual pasture growth for meat producers.
• On a day of 27C, unsheltered cows will produce 26% less dairy milk than shaded stock.
• Planting local trees, shrubs and groundcovers, rather than exotics or plants from other regions, provides food, shelter and nesting material for local wildlife. Using local plants also maximises the chance of restoring plant-animal interactions such as pollination and seed dispersal.
• Insectivorous birds including honeyeaters, consume about 24-38 kg of insects per hectare per year in Eucalypt woodlands.

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