For the past few months Deborah and I have been spending most of our hiking hours on the many trails of Harrison Hills Park. We are compiling a list (and a set of photographs) of the flowering plants of the park, and Deborah is developing a web site for these images. We will let you know when and where we publish it. Through April and May we felt an incredible need to be out on the trails every week or even twice a week so that we could keep up with the rapid changes of the season. Once we got to June, though, we had anticipated a slower pace of change and even thought that as the summer went on we would reach some sort of equilibrium and constancy.
But, we were wrong. We have been reminded that change is maybe the only consistent thing in Nature!
The hiking trails in the park have become narrow tunnels encased by walls and ceilings of increasingly intertwined leaves. The color green dominates your visual field as you walk and even gets to be a bit monotonous and numbing. There are still some large flowers punctuating these green expanses (like the long-lasting, white, multiflora rose flowers that surround you with their sweet scent and the tall, showy whites and pinks of Dame’s Rocket), but mostly the more recent flowers are quite small and inconspicuous. If you walk past them too quickly you will miss them, and there is a lot that can be missed! On each of our six most recent hikes (slow crawls for the most part!) we have found between four to six new plant species. Our plant list for the park keep growing longer and longer! As long as we keep looking, we see something new!
Spring is an easy time to explore and write about our ecosystems. New species of plants and animals pop up against the relatively quiet background of the fading winter. There are sudden changes to notice and report, there are sudden arrivals of migrants and sudden emergences of species coming out of hibernation or metamorphosing into new forms.
Summer, though, has a dense overlay of consistency that makes the changes harder to see. Summer is all about leaves, and photosynthesis, it is all about gathering energy for growth and for properly fueling all of that Spring-based reproduction and making sure that the next generations get distributed and established. For the animals, it is all about parental work and nurturing. The level of concentration and intensity of activities push all of that show and singing of the Spring onto the back burner. The woods are much quieter now that they were a month ago. Summer is the time of abundance that needs to be seized for survival.
Charles Darwin, pondering Thomas Malthus’ essay on populations, noted that there was by necessity a very high mortality rate in young animals. Their small sizes and lack of experience in recognizing and avoiding predators or other physical perils allow only a small percentage of young individuals to survive into adulthood. We have observed some of this ongoing carnage on every hike. We see crows and blue jays raiding songbird nests. We see broken eggs scattered along the trail and have watched fat bellied black snakes sliding down the tree trunks. But Darwin’s great insight was that this high rate of mortality was actually a sculpting force for each of the species. The selection of the most alert, the fastest, and the most intelligent or quickest learners among the young gradually improves the species. The selection for those eggs that are the most well hidden or for those nests whose parental pairs are the most careful not to advertise their locations all benefit the species in the long run. Predators are a beneficial force for any species, and their absence in an ecosystem can be disastrous.
The absence of predators may be the fundamental reason why white-tailed deer are such a problem in our forests and also in our urban and suburban environments. Too many of the fawns survive each year and the very large herds decimate the young tree seedlings of our regenerating forests along with the gardens and ornamental plants of our yards. I had a student several years who suggested that mountain lions should be re-introduced into Pennsylvania to get the deer herds under control. Their impact, though, on humans, especially little humans, might be too high of a price to pay for relief from the deer.
We have a herd of six deer that cycle daily through our property. We see them at very regular times in the morning and in the evening. One of the does of this herd has separated herself from the group and has been hanging out in the thickets around the edges of our woods. Her profile strongly suggests that she is pregnant and is getting ready to give birth. From the experience of recent years I can predict that she is carrying twins, too. Intellectually, I would have to consider this a continuation of the ecological tragedy of the deer over-population crises. But emotionally, both Deborah and I are very excited at the thought of a new life coming into being and at the coming presence of two fawns around our home.
Sometimes you just have to let your biophilia carry you along and not worry too much about the science or outcomes.