In the third part of our natural navigation series we look at how the plant kingdom can help inform our direction or location. If used in conjunction with other natural navigation techniques it can make direction, location and route-finding both extremely effective and also extremely rewarding. Using all these techniques rely on and help develop good observation and awareness skills. This in turn really helps unlock a more fundamental connection with and appreciation for nature.
Plants, habitat, soil and climate
Plants obviously are pretty static (!) so they have an tendency to congregate in greater numbers in preferred environments. This means that if they are shade loving, acid-soil loving, frost-hardy plants then they will grow in certain places and in certain ‘aspects’ whereas other plants might not prosper. It is therefore useful to know before you travel to an area if there there are any macro trends to the habitats, soils and climates. For instance, it is worth taking note, not only of the height of the treeline on the north side of the mountain compared to the south, but also if the species of tree is predominantly different. The side of the mountain that is exposed more to extremes of climate will tend to have a lower tree-line and maybe also a more hardy type of tree. This might help with your orientation and direction-setting / keeping even in poor visibility. Knowing what plants are rare or are specific to certain geographic areas may also help – Alexanders, the edible umbellifer, has a tendency to grow in greater profusion near the sea. This does not mean in sight of it but in proximity to it – which might still be several miles away. However this can only be used as a rough guide as there are always exceptions. Some parts of a country might have more common plants and trees than other parts where they are rare. So a quick look at plant distribution maps to identify ‘marker’ species might also be a useful addition prior to departure.
Plants and moisture
Most plants need moisture. Some more than others – lack of moisture can be due to lack of rain-fall, lack of run-off, well-draining soil types, heat/sun and the dessicating qualities of the wind. This is particularly relevant when making assumptions about moisture loving plants such as moss. Moss likes moisture and even the south side of the tree or a wall might have conditions which promote its growth even if it contrary to the myth of moss growing on the north side of a tree (away from the sun) in the northern hemisphere. Micro or local conditions are very prone to dissproving this rule. So please beware.
Plants and wind
Plants can be good indicators of prevailing wind conditions as they are shaped by them over time.
Trees are a good example of this – we have all see those exposed wind-blown trees whose branches have been bent by years of the relentless prevailing breeze. Know the direction of this wind and you have natural direction finders.
Wind also affects smaller plants – some will seek shelter in the lee of rocks or obstacles to stay out of the wind. Even grasses will leave the mark of being exposed to the prevailing wind – even if the wind is blowing in a different direction. The wind-blown grasses of the moor on exposed slopes (ie: not channelled by the contours of the land) will be flattened away from the prevailing wind.
Wind loosened grass collects on the windward spikes of gorse bushes – just look for the general ‘face’ of bushes in an area with the heaviest ‘snagging’. Around the edge of rocks the slipstream of the prevailing wind may shape the grass too.
Plants and sun
The sun can also affect plants many plants follow the track of the sun, although I am yet to find one who’s blooms face where the sun even on a cloudy day. However, some plants align themselves in relation to the sun in other ways – the prickly lettuce or compass plant aligns it leaves vertically and point in a north-south direction on hot-sunny days in an attempt to keep cool in the midday sun. Taking the average alignment of a couple of these plants and their leaves in an exposed spot (it: not affected by building or trees) will give you a fairly good estimate of which way north and south is.
The shape of some trees can be markedly shaped by the sun. If you walk around a tree which stands on open ground and is not affected by neighourbouring trees, building or landforms you should be able to pick out differences between the north side and the south side. Bear in mind that some species of tree are very susceptible to showing this and some are not, just as some species are very susceptible to wind shaping which might confuse your ‘reading of the tree’.
The south side or sunny side of the tree (in the northern hemisphere – the opposite in the southern hemisphere) will have branches that reach out more ‘horizontally’ towards the sun. On the north side of the tree the branches will have a tendency to reach upwards more vertically towards the light and to angle the leaves in a way to gain maximum benefit from the sun on the opposite side of the tree. As you can see from the picture below this can dramatically alter the shapee of the tree…thereby giving you an indicator of the direction of south. This exagerated growth on one side of the tree can be seen on many other plants and shrubs but is more visible on trees.