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Chapter 7 ECOLOGICAL FIELD SURVEY RESULTS - ECOLOGICAL VALUE ASSESSMENT

7.1

ECOLOGICAL VALUE ADJUSTMENT BASED ON FIELD SURVEYS

7.1.4

Mixed Shrubland (Indicative Ecological Value: High)

Large patches (> 6 ha) of mixed shrubland were recorded in Tai Lam Country Park (Sites 30f and j) which were highly heterogeneous in terms of habitat structure and species composition. The majority of the correctly classified mixed shrubland was generally well-preserved and subject to little human disturbance. However, a number of the sub-sites were found to be occupied by wasteland (13) which generally supports low species diversity. Ecological value of these sites was downgraded as they supported mainly weedy species and comparatively lower species diversity and structural complexity than other mixed shrubland. Some of the surveyed areas were found to have been disturbed by hill fire but undergoing gradual recovery as evidenced by the presence of a number of young pioneer tree species on the burnt area (eg Site 30e). Mixed shrubland sites that were adjusted from their indicative ecological value are presented in Table 7.1d (see Table G4 of Annex G for details).

Table 7.1d Rationale for Ecological Value Adjustment of Mixed Shrubland Habitats based on Field Surveys
Site No.	Site Name	Sub-site	Ecological Value After Field Assessment	Rationale for Ecological Value Re-adjustment
29	Pak Nai	a	Medium	The identified mixed shrubland had its ecological value downgraded as it originated from an abandoned orchard and supported comparatively low species diversity.
		b	Medium	Habitat resembled a typical wasteland and supported comparatively low species diversity.
		c	Medium	The identified mixed shrubland had its ecological value downgraded as it resembled a typical wasteland and supported comparatively low species diversity.
		d	Medium	The identified mixed shrubland had its ecological value downgraded as it resembled a typical wasteland and supported comparatively low species diversity.
		f	Medium	Habitat had its ecological value downgraded as it resembled a typical wasteland and supported comparatively low species diversity.
		h	Medium	Habitat had its ecological value downgraded as it supported comparatively low species diversity.
		i	Medium	Habitat had its ecological value downgraded as supported comparatively low species diversity.
31	TaI Mo Shan	c	Medium	Habitat had its ecological value downgraded as it supported comparatively low species diversity..
31	TaI Mo Shan	f	Medium	Habitat had its ecological value downgraded as it supported comparatively low species diversity.
32	Kwu Tung	a	Medium	Habitat had its ecological value downgraded as it supported comparatively low species diversity.
33	Shing Mun	a	Medium	Habitat had its ecological value downgraded as it resembled a typical wasteland and supported comparatively low species diversity.
35	Pat Sin Leng	f	Medium	Habitat had its ecological value downgraded as it supported comparatively low species diversity.
36	Ma On Shan	a	Medium	Habitat had its ecological value downgraded as it supported comparatively low species diversity.
37	Sau Mau Ping	b	Medium	Habitat had its ecological value downgraded as it appeared to have been burnt recently.
		e	Negligible	Habitat had its ecological value downgraded as it had been modified for landscape purposes and subjected to regular maintenance (no photo available).
		g	Negligible	Habitat had its ecological value downgraded as it had been modified for landscape purposes and subjected to regular maintenance (Figure 7.1a).
		h	Low	Habitat had its ecological value downgraded as it resembled a typical wasteland and supported comparatively low species diversity (Figure 7.1b).
		i	Negligible	Habitat had its ecological value downgraded as it had been modified for landscape purposes and subjected to regular maintenance (Figure 7.1c).
		j	Medium	Part of the shrubland had been disturbed by rubbish dumping.
		k	Low	Habitat had its ecological value downgraded as it resembled a typical wasteland and subjected to regular maintenance (Figure 7.1d).
42	Keung Shan	a	Medium	Habitat had its ecological value downgraded as it supported comparatively low species diversity. Habitat established by planting shrubs on cleared slopes.

There were five patches of re-classified Mixed Shrubland which also had their ecological value downgraded after field verification. Four of the sub-sites were adjusted to medium and one sub-site was considered of low ecological value (Table 7.1e).

(13) Wasteland is defined as those areas formed as a result of human activities and either wholly or partly covered by weedy or ephemeral vegetation.

Table 7.1e Rationale for Ecological Value Adjustment of Re-identified Mixed Shrubland Habitats based on Field Surveys
Site No.	Site Name	Sub-site	Initially Mapped Habitat Type	Ecological Value After Field Assessment	Rationale for Ecological Value Re-adjustment
20	Pak Sin Leng	c	Lowland Forest	Low	Habitat had its ecological value downgraded as it had been highly disturbed by rubbish dumping and clearing of vegetation. It supported comparatively low structural complexity and species diversity (Figure7.1e).
104	Shap Pat Heung	f	Shrubby Grassland	Medium	Habitat supported comparatively low species diversity.
107	Ho Chung Valley	a	Shrubby Grassland	Medium	Habitat resembled a typical wasteland and was subjected to household garbage dumping.
108	Victoria Peak	a	Shrubby Grassland	Medium	Habitat supported comparatively low species diversity.
108	Victoria Peak	k	Shrubby Grassland	Medium	Habitat was found to have been disturbed as a footpath had been constructed along the edge of the habitat.

2005

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最近修訂日期: 二零零五年十二月二十二日