lwingkay

Interesting to read the emails in this thread, especially Wmartin's quote from Bill Hau's reply.

I am more layman than many a layman in Hong Kong about forestry. Dr Hau’s did make more a bit more informed about the paper bark trees. I do hike, too, sometimes. These are the background for the following points I would like to make in response to what Wmartin had initiated here:

a) It seems to me that the distribution of the paper bark tree in Hong Kong is pretty confined to the roadside, the reservoirs and their catchment areas. Probably, they have been planted there in consideration of their ability to adapt to extreme dryness and severe water-logged situations, which are exactly the case for the roadside and the reservoir areas. It seems that the distribution is not to a rampant stage, posing threat to fire safety and biodiversity.

b) I have no ideas whether birds dislike frequenting the paper bark or not. Probably, the seed capsule is too hard for birds to open and the smell of the crushed leaves is offensive, so the latter prefer other trees. However, I do see insects and birds loitering by the brush-like flowers from time to time and perching on the branches to rest or among the foliage to hide. The paper bark may not be like, for example, the mulberry where birds like visiting but it definitely is good to the bird in some respects.

c) Even if the paper bark is not preferred by the birds and its bark too brownish grey to be aesthetically attractive, it is not reasons enough to have them chopped for there are still other functions that they can discharge in their habitat, e.g. providing a windshield for other plants, greening our environment and holding up top soil from erosion. Chopping is favored when their aggregation in a certain place is to a level that poses fire risk and negative effect of biodiversity.


d) The prolifieration of paper bark trees in TPK and Shing Mun Reservoir is more than natural, a place where there is plentiful supply of water. Probably, they are one of the best species to cope with the environment and there are few species that can proliferate under their crowns now. In fact, due to the fact that the seed capsules are difficult to break, as Dr Hau says in his reply, in the absence of high temperature, there is a slight chance that the paper bark can further extend their reach to the locality beyond their own groves. So, as regards the whole landscape in the forest, macroscopic biodiversity is still in place. The paper bark grove is only a concentrated presentation of the paper bark species in the whole natural environment of the locality, posing no threat to the overall biodiversity.


About the issue of bureaucracy mentioned in the emails, would like to say a bit about my view. Frankly speaking, chopping or not chopping is an issue that concerns few people. Most of us concern about the presence of more trees around us as measures to keep the air fresher. However, when it comes to a decision, the issue usually become politicized and most of the time, it ends up in a political farce. And because of this, the government has to take every precaution to balance the interest of different parties in our society; otherwise, the government will be in deep shit. So, I tend not to say that the government is slow with everything. They simply have lots of things to take into consideration. Perhaps, there are members in the civil service who are reluctant to do what they should to have their work done properly but most of them are obedient and industrious, who really want to serve well. What lying in the road is the interest of the public that they have to balance, which has made it difficult for work to be discharged at a rate that we laymen expect it to be like. It is therefore judging to say that they are insensitive to public opinions, desk-bound or that they do less to avoid committing mistakes. We, onlookers, set out from our own perspective and look out differently from our own dens but the government has to be encompassing in the course of administering for the wide public. No matter what, it is worth the while to put ourselves in others’ shoes sometimes.

'Chopping or not chopping' is a healthy issue worthy of exploring into for the sake of the long-term health of our forest.  It seems that from time to time, our government has the need to do something about its forestation policy to make it well conceived of and long-term in context as far as practicable. The planting of Acacia confusa is a lesson that the government can learn from as this exotic species from Taiwan grew so rampantly in Hong Kong that it eventually becomes invasive to the local species, posing threat to biodiversity and change to the local forest landscape. They should consult naturalists and botanists for timely policy change from time to time.

Have to say that I am like the majority. I want to have more green trees and I seldom bother what species they are. Wmartin's reminder here does give me something to think on and to learn from regarding loving our natural environment.

Peter

lwingkay

Did pay more attention to the natural landscape around us lately as a result of the discussion initiated here. Tended more and more to agree to felling some trees in some specifically chosen spots in order to enable more varieties of species there to thrive and to add value to those spots by nature of functions that they have been serving among Hong Kong people.

Did surf the Internet about the paper bark trees issues and most of the pieces I read were for the argument that the quantity of paper bark tree in quite some countries has been to an invasive level affecting indigenous species. Frankly, this surprised me for I did not know about that before; I have been thinking many a Hong Kong people do not as well. Here is a pick from the Internet that systematically outlines the reasons behind the invasiveness: http://www.nps.gov/plants/alien/fact/mequ1.htm.

Understandably, opinions/feeling about 'chopping' must be pretty mixed if they are to be fielded for wide consultation, especially in recent years when more and more people are concerned about protecting trees and idyillic plant groves in our natural landscape. Evidently, empirical data is essential for putting up a strong case that chopping is good for the environment and biodiversity, and that it will do no harm whatsoever to the species-specific groves.

It seems, however, that at present, most of what we have about the advantages and disadvantages of the paper park tree are common-sensical in content or textbook-based prediction/deduction which may be out-of-context with the situation that we are having in Hong Kong, e.g. TPK as mentioned here.

Further, whether or not bird biodiversity is really associated with the dominance of paper bark trees in TPK is still probably something pending to be verified. Perhaps, there are more effective means to do other than chopping.

In the meantime, the public has to be informed of the pros and cons so that they are able to make informed judgment of their own.

Obviously, AFCD and parties interested in this issue have to carry out investigation to justify their course of action.

Admittedly, for many a member like me who used to concerns predominantly about greenness and who is ignorant of the subtlety in ecological balance among species, this thread's sharing is a good chance to expands my horizon about biodiversity. Thanks.   

Regards,
Peter

[ Last edited by lwingkay at 14/09/2008 11:09 ]

lwingkay

Here is the link to Dr Billy Hau's paper on paper bark trees in Hong Kong in Porcupine, Issue 24 of December 2001.
http://www.hku.hk/ecology/staffh ... Kong-Hau%202001.pdf
Peter

lwingkay

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 ]