In my previous post we discovered a new range of terms to come to terms with when we start to think of the bowling green as an eco-system. While some of these were a bit obscure, like Rhizosphere, most of them are self explanatory. The term Niche, is one of these. We all understand the need to find our own niche in life (well, maybe…I’m still looking for mine:-) Niche describes the unique collection of conditions required to enable our desired grass species to thrive. It’s a good ecological term to keep at the forefront of your mind when developing a program of maintenace for your green.
The process of evolution appears to rely heavily on the struggle between organisms for dominance in any particular environment and our bowling greens are no different.
Competition is another key term in ecology and comes into play when two populations share some aspect of a niche, such as a food resource. There can be a variety of results from the competition between populations, the most common being:
- One population will compete more effectively for the available resources. The population that is more effective will eventually “win” and drive the second, less effective population from their niche. With the niche freed, the winning population will grow to the carrying capacity of the niche.
- Both populations will evolve into less competitive niches. If two populations compete on even terms, it may be beneficial for both populations to modify their niches so that the populations’ niches overlap less or not at all.
In bowling green maintenance there is one species that illustrates this concept better than most.
If an organism can compete and adapt quickly to a changing environment then it becomes a pioneer in a range of ecosystems and habitats, and Poa annua (Annual Meadowgrass) is clearly well adapted to competing in a variety of environments. To achieve this level of adaptability it has an impressive arsenal to call upon, such as:
- Heavy seed production.
- Flowering and seed production throughout the year.
- Flower heads that stay low to the ground to escape the mower and even grazing animals.
- Fast germination of seeds to help new plants establish and get a hold in the soil quickly.
- Poa annua thatch produces toxins which can prevent the germination of the seeds of other species.
Bowling green ecology is no different to the wild in many respects even although the grass has a strong ally (or foe sometimes) in the greenkeeper. Plants compete for physical space, for nutrients and water from the soil and for sunlight. In turf areas the ability to monopolise the resources of their environment at the expense of any other grass or weed species gives our desired species (usually bentgrass and/or fescue) the edge.
To form a densely populated, high performance bowling surface requires our favoured species to suppress the other species by removing their access to the vital resources of:
- Light – by growing above and over the other species to suppress access to sunlight.
- Physical space – by tillering (producing new shoots) and spreading quickly into spaces not yet taken in the soil.
- Nutrients – by producing more invasive and/or exploratory roots that can monopolise the food resource leaving insufficient for other species to thrive.
- Water- drought tolerant grasses can use summer drought to move into areas where less drought tolerant species have died back.
A Performance Bowling Green Management Plan takes account of natural changes at turf level and within the soil, and adapts to allow for changes in management practices, climatic changes and seasonal changes.
Some of the key factors that benefit or hinder a species in its quest for dominance are described as Environmental Stresses. It is these stresses that drive the evolutionary process and as such can be used by the bowling greenkeeper to create conditions that are more suitable for the desired species than for others. There are a number of ways for greenkeepers to manipulate the environment artificially, or indeed to take advantage of naturally occurring stresses, in order to alter the balance of the bowling green ecosystem in favour of the desired grass species.
And next time, we’ll look more closely at Environmental Stresses, the problems they cause and the ways in which we can exploit them for our own ends in bowling green maintenance.