Thursday, August 8, 2013

15. Matobo Time











Please visit the The Arts in Focus to obtain information about our 2014 Matopos Calendar - 
an initiative supporting rhino conservation in Zimbabwe.

Matobo Time

We sat high above Matopos on the warm granite with the cool breeze in our faces when Emile asked me how long I am going to be. “A lifetime...,” I answered. 

I watched him for a little while as the wind played in his hair. “The lifetime of the bacteria decaying this dung beetle or the lifetime of the big guy down there?” he asks as he sits up and points with a piece of grass to a white rhino down below in the valley. In my mind’s eye I suddenly see this place in a different dimension. I see Matobo made up, constructed of time, the make-up of life itself. At the smaller lever I “see” mitochondria buzzing around in cells and cells dividing and things growing and happening relatively fast at a microscopic level, as I did as a young zoologist. At the other end of the scale, under my hand I rubbed the fine dust off the granite rock, also at a microscopic level but at a temporal scale even my relatively intelligent mind struggles to fathom.  I wonder how long that took. As I gazed over the landscape surrounding me, instinctively the scientist in me started to divide the world around me into discrete groups of individuals, events and processes based on the relevant timescale during which it happens or lives. 


When you consider the whole, the entire ecosystem, the time scale is millennia or eons, the longer yardsticks of time. However, when you break the system down into an array of increasingly smaller sub-systems, smaller and more precise units of time are required. You could measure the lifecycle of a rhino in years, while months are more appropriate to measure the gestation period of his equally obnoxious wife, but the passage rate of the grass through his digestive system is more appropriately measured in days. Fertilization of his calf took place within a few seconds while oxygen exchange in his enormous lungs is probably measured in smaller fractions of time. Many measures of time are appropriate to discuss the lifecycle of our rhino, but for others the entire process is over in a few seconds or even less. 

The shortest of events and lifetimes



A gust of wind may sweep across a field of grass and a million grasses are pollinated, just like that. End of story. A significant event that took a few fleeting seconds, but its impact will be prominent when a million grass seeds germinate in a few months time after the rains. Some critical events take place over a very short period of time. Raindrops fall, and the soil is instantly wet, just as the water was a fluid one moment and the next it's a gas.  Some smaller species complete an entire lifecycle in a few days. Some mysterious flowers only open to be pollinated at night, and then only for a few nights, and then its all over. Many of the smaller critters and plants typically only live for one season, then their duties as denizens of their world is complete. For them seconds and hours and days are far more relevant. Months are towards the outer extreme of time measurement for them.

Some lower organisms, live for only a very short periods of time, those single cell organisms and smaller invertebrates in ephemeral ponds transcend dry seasons as spores.  Similarly, some lower plants, some fungi live for very short periods of time, and are highly opportunistic in their approach to life. These shorter life cycles are controlled and affected by the duration of shorter environmental cycles, like day and night, the seasons with wet and dry cycles, cold and warm periods, and even the ratios between light and day. 

The annuals
Some plants and animals live according to very strict annual cycles. One year is the limit for them. Their life-cycles are punctuated by the seasons, normally starting with the rains and ending with the winter. Then there is a period of rest, the dormant stage. Annual plants transcend this period as seeds. The plant itself is no longer there, but many seeds remain behind to initiate new cycles of life. The animal equivalent to annuals are the many insect species who live for only short periods of time and survive the harsh period as eggs. Butterflies are the most typical of these. The eggs hatch in spring and the caterpillars eat their way to adulthood, go through their incredible metamorphosis and emerge as butterflies, painting the landscape in small sections from flower to flower.


For most of these smaller creatures, the annual cycle is all they will live through and experience. No memories of last year, or the year of great floods or the drought of 1982. They just have now, as there is no real past, apart from yesterday and last week and if they are really lucky last month. There also is no real future, no next year or ‘one day’. Perhaps they don't miss it because they don't have it. Perhaps now is enough.

Those who live a little longer
Others have a past and a future. I watch the young impala play, learning about their futures.Their lives are measured in years rather than months. Other processes within them are measured in shorter yardsticks. Their gestation period is 7 months. They are affected by the annual cycles, breed highly seasonally so all the lambs are born in a very short time. Like the life cycles of the short lived species of Matobo, their lives are hugely controlled by the seasons, breeding cycles, times of abundance and shortages,  but the adults cross over into the next season and the next. For them, there must be more of a sense of the past and the future. Hence, the learning as youngsters, butting heads and chasing each other in mock predator prey plays. 


The barrier from the one season to the next, in Matobo, is winter, the dry season. I often think, in terms of evolutionary jumps/progress, crossing that invisible barrier must have been a great challenge and achievement. There are many ways in which to cross that bridge between being one and being two years old! Some plants do it by going dormant in the harsh part of the year. Some trees loose their leaves and sit out the winter. They just hang in there, expending as little energy and resources as possible. Others, like many reptiles will eat as much as they can before the winter and then find a cosy place to hibernate, allowing their body temperatures to drop. They use as little energy as possible to stay alive and then emerge pretty lean when spring arrives. Others are simply big enough, mobile enough and store enough reserves to carry them through winter. These are often the warm blooded part of the family, those who can collect and burn energy to stay with us on the surface during winter. These guys can often live for many many years. Think rhino and elephant. The cold blooded strategy also works well for crocodiles and pythons and tortoises. They live long because they use their energy sparingly and add up the years that way. For them the lifespan yardstick is very long... decades.



Leaving individual lives behind...


There are other timescales that are also relevant. Those which goes beyond the scale of individual lives. When we think about how the whole of the system evolves and develops, it essentially operates at a time scale way beyond the relevant measures of the oldest of individuals. The growth of, and the interactions between individuals within populations, allows for individual species to evolve into functional groups of communities, whether they are antelope communities, grasslands, forests or wetlands. At this level, shorter processes and limited lifespans merge into one another and all fuse to produce larger infinite timescales. The shorter timescales are still important, but they have merged into one another and like the different pieces of a mosaic they loose their individual relevance when looked at from a distance. Similarly, at least in my mind the cyclic nature of the smaller time intervals merge into processes of extended duration, creating the larger infinite temporal landscape. 



This is the scale at which the larger environmental processes are important. Cycles of dry and wet periods follow on each other, the result being the specific dynamics of forests and grasslands competing for area, predators and prey oscillate in numbers as some species increase and others crash.  All of this contributes to the overall variability within the larger system. These are experiences individual short-lived individuals and annuals species will never know about.

We watch the sun rapidly falling from the sky, announcing the end of another day, and we are forced down the hill to get to our vehicle before darkness turns Matobo into a stage for the nocturnal critters to play their role.

Emile walks down in silence, guiding us, and I think about circadian rhythms. It is the pulse of life,  while lunar cycles pace out the months, adding up into years, and years becoming decades and decades accumulate into longer and longer time periods, making up time itself and we are in there somewhere.

Please visit the The Arts in Focus to obtain information about our 2014 Matopos Calendar - an initiative supporting rhino conservation in Zimbabwe.