Fig 1.
Location of the Hengduan Mountain Hotspot and spatial distribution of 159 protected areas according to three constructed administrative grades: national protected areas, provincial protected areas, and other protected areas.
Table 1.
Classification criterion of integrated threat categories.
Fig 2.
Local threat index calculated by four potential influence factors including residential development, agriculture development, energy production and mining, and accessibility in the Hengduan Mountain Hotspot.
The numbers represent seven ecoregions. I: Northeastern Himalayan subalpine conifer forests (NHSCF), II: Nujiang Langcang Gorge alpine conifer and mixed forests (NLCMF), III: Northern Indochina subtropical forests (NISF), IV: Southeast Tibet shrublands and meadows (STSM); V: Hengduan Mountains subalpine conifer forests (HMSCF); VI: Yunnan Plateau subtropical evergreen forests (YPSEF); VII: Qionglai-Minshan conifer forests (QMCF).
Fig 3.
Boxplot summaries of the values of local threat index inside protected areas and outside protected areas of seven ecoregions, including three western ecoregions (a) and four central-eastern ecoregions (b).
Boxes shaded in gray indicate that the value of local threat index was significantly different between inside protected areas and outside protected areas for each ecoregion, based on a Wilcoxon rank sum test at P value ≤ 0.05. The bold lateral bars represent the median values of local threat index, the boxes represent the first and third quantiles, and the whiskers depict the range of the data.
Fig 4.
Integrated threat categories mapped in the Hengduan Mountain Hotspot considering both the local threat index and surrounding threat index.
Fig 5.
Proportions of six integrated threat categories contained in PAs and PA buffers based on three kinds of protection levels for PAs shown on the left, and four kinds of ecosystem characteristics and protected targets for PAs shown on the right; 0–5 km and 5–10 km represent PA buffers at 5-km intervals.
Fig 6.
The relationship between the size of protected areas and the proportion of integrated threat category 1 and 2 areas that PAs and PA buffers contain.