Hiking in Mai Tze Lam and Pondering on from Tony’s
Lately, I spent an afternoon walking up to Mai Tze Lam in Ma On Shan to do some shooting and found that trees there are pretty thick, well grown and mixed in varieties and that they are scattered in a relatively well defined pattern.
First, about the varieties. The commonest species are, in descending order, the acacia, bauhinia and the ivy tree. Scattered ones are: The elephant's ear, lance-leaved sterculia, Chinese banyan, lebbeck, sweet gum, flame of the forest, China berry, rhododendron, queen crape myrtle, sea hibiscus, cotton tree, swamp mahogany and turn-in-the-wind.
About the distribution, it is interesting to see that the acacia spread out evenly along both sides of the uphill trail. To the side of the acacia, the ivy tree is common. Probably, the ivy tree prefers to grow next to an acacia by nature but it is likely that AFCD had planted them together for a certain reasons, e.g. the acacia a good windshield and pretty resistant to fire and their togetherness may serve a long term healthy growth purpose.
The acacia is the king of the forest there. They are tall and their crowns roof the forest, not only that but they also hang their branches out to shade the trail along which they run. If this situation persists, the crowns will make it difficult for the shorter plants below to grow properly. Perhaps, it is worthwhile to do something about it.
About biodiversity of bird species, do have to say that the bulbul, magpie robin, Japanese white eye, spotted dove and sparrows are the commonest. Occasionally, you may see the long-tailed shrike, black-collared starling and black-throated laughing thrust. There must be other species, e.g. the barbet, in the woods, I think, but I doubt that there are birders or officers who have been there to take records of the species deep down there.
We leave the species deep in the woods for the time being. Judging by the species that were seen along and beyond the trail, can we say that the kinds of trees mentioned in the second paragraph are still not good enough for more varieties of species to be possible? Has that been the case because the above bird species are more adaptive to the aforesaid plants species, so we can see them more as a result? Or is it that these bird species are lower in the food chain, so more numerous and discernable? Or can we say that it is because we have not penetrated deep enough into the forest that we fail to identify other species?
I have been thinking if there are archives in Hong Kong that can give us a better knowledge about the state of being in the natural habitats in Hong Kong as well as the situations of biodiversity in there.
Back to Tony's recap from the Taiwanese article he read. Tony said that [the Taiwanese article] suggested that different thinning levels did not show significant effect on abudance and species of small mammals and non-breeding birds [but it affected] the abundance of ground invertebrate. In the first place, it is an interesting finding but my first feeling is its validity to localities that do not resemble Taiwan’s; but evidently, the methods as well as the outcomes are worth looking into. Second, it seems to reflect the kind of picture that I saw from the hiking up Mai Tze Lam: that despite the presence of a variety of plants, the variety of bird species present may not be proportionally at a higher rate. Have to say again that it is an interesting counter-finding but, there must be other cases that are to the contrary elsewhere that we can learn from in planning species thinning locally in Hong Kong.
Back to my feeling about thinning. My stance is: (a) very positive and it has to be done from time to time for better forest management and the equilibrium of growth of different plant species; and (b) positive from the point of view of attracting more bird species because in principle more plant varieties will certainly do birds some good one way or another. However for (b), before thinning, we have to take an account of the bird species in the natural habitat in question to decide whether or not biodiversity problems exist, whether or not thinning is justified from other biodiversity considerations as well as considerations of environmental and forest protection origin.
Regards,
Peter
[ Last edited by lwingkay at 20/09/2008 12:06 ]