A healthy and productive grassland contains a diversity of biological creatures.
It has long been known by savvy graziers that the amount of biodiversity in a grassland ecosystem can be directly linked to how intensely the land is used, whether by livestock, wildlife or some other use.
Intensive use of grassland, through overgazing for example, can lead to declines in biodiversity. Researchers from Switzerland and Germany have discovered it is the rarest species that suffer the most. Their findings indicate that varying land-use intensity may be the answer to reducing these negative effects on biodiversity.
Unlike past studies that only looked at single or small groups of organisms in an ecosystem, researchers at the University of Bern were able to compile a uniquely comprehensive dataset on the biodiversity of up to 49 groups of organisms. This dataset included bacteria, fungi, plants, and animals.
This data was then used to look at 150 grassland sites across three different regions of Germany. Sites varied from extensive management to light grazing to intensive management to mowed grasslands with high fertilizer application.
Data compiled allowed the researchers to create what they refer to as a novel index of "multidiversity" which measured the total ecosystem biodiversity. You can read more about the details of the study in the December issue of PLOS One here.
The take-away results from this study were:
- Increasing land-use intensity leads to declines in overall biodiversity of grasslands.
- Grasshoppers and butterflies declined most strongly.
- Biodiversity was significantly higher in grasslands with varying land-use intensity over the last few years.
- Rare species particularly benefited from changing land use over time. Biodiversity was almost twice as high when land use varied between years.
So what does this mean for the cattle business? The researchers arrived at two important conclusions. The first was that this new index to measure biodiversity may be a useful tool to assess the effects of conservation measures and restoration efforts. This could potentially be useful in circumstances where grazing rights come under speculation due to threatened species and other environmental concerns. Having a more effective way to measure grassland biodiversity will give us a better understanding of current organism populations and provide useful information that would help land managers to develop better land-use and grazing plans.
Second, varying land management over time could be used as a tool to maintain grassland biodiversity. This could be done by altering stocking rates or density and changing time of year and frequency of grazing using grazing management strategies such as rotational and holistic planned grazing. The researchers said this should incorporate an effective land-monitoring system that takes biodiversity into consideration.
While good graziers may have long known these facts, I find it encouraging to see scientists reproving these things. As this study proves, land management tactics such as grazing are tools which, when used properly by man, can have either very beneficial or very detrimental effects on the land they are used.
I hope someday the anti-livestock-grazing people will quit blaming the cattle and take a long, hard look at the real culprit – ourselves. Yet only when we correct our grazing mismanagement will we really start to make a difference in the biodiversity and productivity of grasslands and rangelands.