﻿PLANTS 
  OF 
  CHINA 
  — 
  WALKER 
  341 
  

  

  sea 
  and 
  the 
  consequent 
  intensity 
  of 
  the 
  rainfall 
  and 
  its 
  distribution 
  

   through 
  the 
  growing 
  season. 
  The 
  monsoon 
  reaches 
  the 
  Yangtze 
  River 
  

   in 
  April 
  and 
  Kansu 
  in 
  late 
  summer. 
  Furthermore, 
  the 
  regularity 
  of 
  

   the 
  monsoon 
  winds 
  decreases 
  toward 
  the 
  north, 
  where, 
  because 
  of 
  the 
  

   caprices 
  of 
  these 
  winds, 
  occur 
  most 
  of 
  the 
  well-known 
  periodic 
  famines 
  

   of 
  China. 
  For 
  instance, 
  that 
  of 
  1877 
  and 
  1879 
  in 
  Shansi 
  was 
  the 
  result 
  

   of 
  a 
  continuous 
  current 
  of 
  air 
  flowing 
  down 
  the 
  Yangtze 
  Valley 
  which 
  

   prevented 
  the 
  monsoon 
  winds 
  from 
  the 
  south 
  or 
  southeast 
  from 
  reach- 
  

   ing 
  northern 
  China 
  as 
  they 
  usually 
  do. 
  

  

  As 
  in 
  most 
  of 
  the 
  northeastern 
  floristic 
  region 
  and 
  in 
  the 
  semi- 
  

   tropical 
  part 
  to 
  the 
  south 
  one 
  of 
  the 
  most 
  significant 
  features 
  of 
  the 
  

   vegetation 
  in 
  middle 
  China 
  is 
  its 
  alteration 
  by 
  man. 
  Wherever 
  agri- 
  

   culture 
  is 
  at 
  all 
  possible, 
  we 
  find 
  the 
  native 
  wild 
  vegetation 
  entirely 
  

   replaced. 
  The 
  demands 
  of 
  the 
  dense 
  population 
  for 
  fuel 
  and 
  other 
  

   plant 
  products 
  are 
  so 
  great 
  that 
  the 
  original 
  vegetation 
  on 
  the 
  neigh- 
  

   boring 
  hills, 
  which 
  cannot 
  be 
  cultivated, 
  has 
  been 
  largely 
  destroyed. 
  

   Only 
  the 
  hardiest 
  native 
  plants 
  remain, 
  unless 
  protected 
  by 
  temples 
  

   or 
  monasteries 
  or 
  sometimes 
  by 
  enterprising 
  villages 
  in 
  communal 
  

   forests 
  or 
  woods. 
  True 
  forests 
  remain 
  only 
  where 
  they 
  cannot 
  be 
  ex- 
  

   ploited 
  profitably 
  because 
  of 
  their 
  distance 
  from 
  rivers 
  on 
  which 
  logs 
  

   can 
  be 
  floated 
  to 
  market. 
  In 
  consequence 
  of 
  the 
  almost 
  complete 
  

   alteration 
  of 
  the 
  native 
  vegetation 
  in 
  the 
  various 
  large 
  basins 
  and 
  

   valleys 
  which 
  comprise 
  this 
  area, 
  we 
  can 
  learn 
  of 
  the 
  original 
  vegeta- 
  

   tion 
  of 
  middle 
  China 
  only 
  by 
  studying 
  the 
  forests 
  still 
  remaining 
  on 
  

   the 
  major 
  divides. 
  

  

  The 
  northernmost 
  forested 
  area 
  is 
  the 
  Tsinling 
  Range 
  lying 
  south 
  

   of 
  the 
  loess 
  area 
  and 
  dividing 
  the 
  Wei 
  and 
  Han 
  Rivers 
  in 
  southern 
  

   Shensi. 
  It 
  extends 
  eastward 
  into 
  Honan 
  where 
  it 
  is 
  much 
  less 
  prom- 
  

   inent. 
  The 
  eastern 
  part 
  of 
  this 
  range 
  reaches 
  up 
  to 
  12,000 
  feet 
  in 
  

   places, 
  high 
  enough 
  to 
  have 
  subalpine 
  rhododendron 
  thickets 
  above 
  

   a 
  zone 
  of 
  firs 
  (Abies), 
  pines, 
  birches, 
  and 
  willows. 
  Somewhat 
  lower 
  

   down, 
  especially 
  on 
  the 
  southern 
  side 
  of 
  the 
  range, 
  occur 
  forests 
  of 
  

   deciduous 
  broadleaved 
  trees, 
  as 
  in 
  northeastern 
  China, 
  but 
  containing 
  

   species 
  less 
  tolerant 
  of 
  the 
  severe 
  winters 
  of 
  that 
  area, 
  such 
  as 
  ash, 
  

   liquidamber, 
  Fortunea, 
  Paulownia, 
  Catalpa, 
  Ailanthus 
  or 
  tree-of- 
  

   heaven, 
  and 
  even 
  bamboo. 
  

  

  South 
  of 
  the 
  upper 
  part 
  of 
  the 
  Han 
  River, 
  forming 
  the 
  northern 
  and 
  

   eastern 
  border 
  of 
  Szechwan, 
  lies 
  the 
  Ta 
  Pan 
  Shan, 
  which, 
  together 
  

   with 
  the 
  Tsinling 
  Shan, 
  is 
  the 
  eastward 
  extension 
  of 
  the 
  Kuenlun 
  

   Range 
  separating 
  Turkestan 
  from 
  the 
  Tibetan 
  Plateau. 
  Forests 
  of 
  

   great 
  commercial 
  importance 
  are 
  found 
  in 
  the 
  Ta 
  Pan 
  Shan 
  in 
  

   Szechwan, 
  southern 
  Shensi 
  and 
  western 
  Hupeh. 
  From 
  them 
  much 
  

   timber 
  and 
  many 
  other 
  products, 
  such 
  as 
  various 
  gums, 
  resins, 
  nut 
  

   galls, 
  edible 
  fungi, 
  and 
  medicinal 
  plants, 
  are 
  exported 
  to 
  adjacent 
  

  

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