I often have wished I could travel back in time through human history, the earth’s history, and even that of the expanding universe. In my travel fantasies, I would be above and fully protected from any exposure to the life-threatening things that might be happening at such times -- wars, diseases, hungry tyrannosaurs, exploding suns, and so on. Hovering above these things with a bird’s eye view, I could watch the evolving plants and animals, and celestial happenings with an overwhelming fascination.
As a botanist and ecologist, I’d really be interested to see what the natural world looked like before the appearance of Homo sapiens, some 300 thousand years ago. Closer to home and to today, I would love to see what our western North Carolina mountain forests, woodlands, savannahs, and river basins looked like before the earliest appearance of any humans, and especially before European settlers began altering the land. Imagine the incredible biodiversity of plant and animal life that had existed prior to human presence!
One change that we have brought especially captures my attention. The introduction of non-native invasive plants, which I’ll shorten to the acronym NNIP from here on. The increasing spread of these plants is considered to be one of the greatest threats to our rare native species. Global trade has caused the introduction rate of such plants to explode since the 1970’s, when an exponential rise in housing and highway construction to meet the growing baby boomer population brought a surging demand for landscape plants in the U.S..
The first successful overseas commercial export of live plants can be traced to Nathaniel Ward, a 19th century London physician who also enjoyed collecting plants and insects. He kept moth cocoons in jars sealed away from the coal air pollution present in the city at the time. Ward noticed that a fern and a grass had sprouted in one of the bottles that had a little soil in the bottom. Fascinated, he watched these plants grow over several years until the lid rusted through, allowing the sulfuric air pollution to kill them. But from this experience he had glazed glass cases constructed, creating the first plant terrariums, and he successfully tested growing different species within them. From there, Ward experimented with sending plants by ship to Australia and had species native to that continent sent back to England. They survived the many months long trips even through harsh weather conditions, and this launched the beginning of global commercial trade of non-native plants that continues to this day.
Generally, only a small percentage of these plants become problematic. It’s estimated that about 10% of imported non-native species become established in their new environment and 10% of those actually become invasive problems. But, those “few” NNIP are wreaking havoc to our natural plant communities, displacing native plants and causing harm to wildlife.
It’s doubtful that Nathaniel Ward could have known how valuable his Wardian Cases, now collectors’ items, would become today, with their beautifully artistic design and durable craftsmanship. And, it is certain that he could not have known, in his era, the harmful impacts his idea of global plant trade would have on natural plant and animal communities in the 21st century.
In my next blog, I’ll get more “into the weeds” about these problematic plants and on what is being done/and what can be done to counter them.
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