Updated: Sep 12, 2021
10 million seeds; as volatile as dust... That's what a single orchid foot produces. How then can we explain that we need to protect this species in our latitudes to ensure its survival?
The power of expansion of life can indeed make one feel dizzy. On a single fern frond, millions of spores fly away in a year. For mushrooms, it's billions. However, undergrowths are not covered with a carpet of ferns or mushrooms... A paramecium, a tiny aquatic protozoan, can produce offspring weighing 10,000 times the Earth in a few days. The reproductive capacity of rabbits is a known example with, in just 3 years, the capacity of a single pair of rabbits allowing the birth of 13 million rabbits. So how come the Earth isn't submerged in just a few days?
Take the example of Scots pine. It produces 38,000 seeds per year. 20% of them are not viable from the start. In the canopy, small proportions will be eaten by birds and other squirrels (2.7%) and others will be parasitized by insects (1.3%). Once on the ground, 2/3 will be eaten by wildlife. The remaining 20% will germinate but most of the seedlings will encounter difficulties where they grow (drought, unsuitable soil...), if they don't get eaten in their young years (rodents, herbivores). Finally, it will be necessary to win the race for light against the neighbors. That's why, out of the 38,000 seeds at the start, only 1 or 2 will give a tree that will reach adulthood.
It is indeed necessary to count on predation, parasitism, locally different living conditions and a whole bunch of parameters and interactions to bring these figures back to something bearable for the planet. Finally, this abundance which could make you dizzy at first is a necessary effort on the part of these species to ensure a simple survival, and we understand then that some such as orchids may need a helping hand when their rate of success is even lower, or their biotopes particularly threatened.