Invasives, Non-natives, and Ecosystems

Published 8-13-2020

The rapid rise of human population has brought with it an explosion of new concerns for humanity. World population first reached one billion in 1804. On a graphic scale we had a roughly linear population for many thousands of years. Since 1804 the graph of human population has resembled an exponential growth curve. World population since 1950 has more than tripled from 2.5 billion to 7.8 billion. The problems for our environment, especially related to invasive species, have been monumental. 

How are invasive species related to healthy ecosystems? Invasive species are not indigenous and are deliberately or accidentally introduced from a different region, often a different continent. By definition, invasive species cause harm to the environment in various ways. Examples are numerous. Invasive species displace native organisms and reduce healthy biodiversity, often propagating at a rapid rate. Humans have introduced non-native, invasive organisms for a variety of reasons. Many invasive organisms arrived unintentionally. One example: early settlers in the New World longed for plants and wildlife typical of their native homelands. They were not cognizant of ecological impacts and many invasives damaged or disrupted their New World environment. Consider the European starling, the English sparrow, the gypsy moth, kudzu vine, and the ubiquitous garlic mustard and wild (poison) parsnip, to name a few.  

The USGS (United States Geological Survey), a scientific agency of the US government, states, “More than 6,500 non-indiginous species are now established in the United States, posing risks to native plants, animals, microorganisms, valued ecosystems, and human and wildlife health. In fact, the current annual environmental, economic, and health–related costs of invasive species exceed those of all other natural disasters combined.” (emphasis mine) The US Fish and Wildlife Service reports 50,000 non-native species exist in the US. 

We contrast another aspect of invasive vs non-native species. Some non-native species do not necessarily result in environmental harm and are not, therefore, termed invasive even though they may have been deliberately or accidentally introduced in a new geographic region. Such non-native species could be beneficial from an environmental, economic, aesthetic, or resource-providing standpoint. Examples are most cattle and farm animals used for food and other products in North America. Imagine our modern society without the contemporary food benefits of beef cattle or poultry. Many familiar animals trace their origins to the Old World. Likewise, a large fraction of fruits such as apples, peaches, pears, and apricots are not native to the Americas. Moreover, much food consumed by cattle, poultry, and humans in our society comes from soybeans and wheat—non-native imports from the Old World. 

In the world of plants and animals, native signifies the region of their original habitat. Many plants have been introduced from the Old World, or from distant geographical sections of the New World. ‘Native’ has acquired a positive connotation while the term non-native may be regarded with some suspicion. Invasive species are justifiably regarded with the most disapproval.

Our post concludes with mention of ecology, defined as a branch of biology dealing with the relationship of all organisms in an environment with each other and to the environment. In the pristine New World discovered by the Norse explorers and later, Christopher Columbus and other Europeans, continents generally possessed a pleasing “ecological balance.”

A WWF (World Wildlife Fund) article defines ecological balance as “a state of dynamic equilibrium within a community of organisms in which genetic, species, and ecosystem diversity remain relatively stable, subject to gradual changes through natural succession.” Their definition concludes with praise for “a stable balance in the numbers of each species in an ecosystem.”

The physical creation with its array of physical constants was divinely fine-tuned long before life appeared on the planet. When life, especially human life, was created, fine-tuning became even more exquisite. We suggest that ecological balance was in the mind of God as a feature of divine fine-tuning. The divine mandate to humans to manage their environment responsibly involves achieving ecological balance to every degree possible. Human life, the crowning achievement of the Creator, was granted the highest thinking capacity and ability. God has gifted humanity with the ability to manage environmental conditions in satisfying and responsible ways. Humans are able to comprehend environmental issues and benefit from understanding the concepts of ecological balance. 

http://jasscience.blogspot.com/2020/08/invasives-non-natives-and-ecosystems.html