Language
Country/Area
No result found
Do you know what ecosystem carrying capacity is? Why is it so important?
The carrying capacity of an ecosystem refers to the maximum population size that a biological species can support in a specific environment. This size is determined by the food, habitat, water, and other resources available in the environment. Carrying capacity also requires that the extraction of resources does not exceed the rate of resource regeneration, and the waste generated must be within the range that the environment can absorb.
Carrying capacity is the maximum load on the environment and reflects the population balance when the number of deaths equals the number of births (and immigration and emigration).
The concept of carrying capacity has applications in many fields, including ecology, agriculture and fisheries. Human carrying capacity is linked to the concept of sustainable population. Regarding the consideration of global human carrying capacity, a book called "The Limits to Growth" in 1972 proposed an in-depth study. Subsequent research and analysis delved into the topic, including much criticism and reflection.
According to a study published in the journal Nature in 2012, 22 international researchers expressed concerns that the Earth may be "close to a state transition," which may cause the Earth's biosphere to become less friendly to human life. The carrying capacity may be reduced as a result.
This concern will continue to grow in the coming years as humans may pass the "tipping point" for safe use of the biosphere.
Many researchers estimate the Earth's carrying capacity to be between 2 billion and 4 billion, depending on the level of optimism for international cooperation to solve common action problems. So how can we ensure that our lifestyles don’t exceed this limit?
History and evolution of carrying capacity
The origin of the term "carrying capacity" is uncertain. The earliest record of its use can be traced back to 1838, but the term was not officially used at that time. In the early 19th century, this concept was mainly proposed in the context of international shipping, and gradually expanded into the field of biology. By the 1950s, the term carrying capacity had been widely used in ecology to express the biological limits of natural systems.
In ecology, calculations of carrying capacity help us understand population dynamics and combine this with birth and death rates. Generally speaking, if the population of a species falls below its carrying capacity, the environment is capable of supporting continued population growth. On the contrary, when it exceeds this limit, the population decreases.
The definition of carrying capacity establishes the delicate balance between organisms and their environment.
Agriculture and carrying capacity
When farmers operate agricultural land, they need to calculate the carrying capacity of the land in order to establish sustainable grazing rates. In Australia this is usually calculated as "Dry Sheep Equivalent" (DSE). This means that the carrying capacity of other livestock is calculated based on a 50kg Merino ram, ewe or non-pregnant ewe and is not limited to sheep.
Globally, different regions calculate carrying capacity differently. The unit used in the UK is "livestock unit" (LU), while the United States and Canada use "animal unit" (AU). These calculation methods can be applied not only in agriculture, but also in the management of natural areas.
Such calculations greatly improve the sustainability of agriculture and reduce the environmental impact of overgrazing.
Sustainable development of fisheries
Carrying capacity is also critical in fisheries management. Sustainable catch (MSY) is defined as “the highest average catch that can be sustained under average environmental conditions.” Initially, MSY was considered half of the carrying capacity, but after further research, this number was slightly adjusted as the species changed.
However, this mathematical model has its limitations in practical applications. Once fishing continues to exceed this limit, the overall population of the species drops to zero. Therefore, the sustainability of fisheries management is always closely related to the carrying capacity of the environment.
Human carrying capacity
Human carrying capacity needs to consider the impact of lifestyle and technological level. Two major economic revolutions in history: the agricultural revolution and the industrial revolution, significantly increased the human carrying capacity of the earth. According to estimates, with the advancement of science and technology, the earth's carrying capacity has been further improved in the short term, but the accompanying environmental costs cannot be ignored.
Although scientific and technological progress has improved the quality of human life, it has also led to the degradation of ecosystem services, thereby threatening the carrying capacity.
In this era of balancing demand and carrying capacity, how can we choose a sustainable lifestyle to reduce our impact on the earth?
