The second problem relates to predictions of future season length and the related
plant activities by using current trends in plant phenology and climate. Numerous
phenological observations, both direct and by remote sensing (see Chapter 4) have
documented that thewarming trends observed during the last century were associated
with earlier greening/flowering and later senescence of plants. However, what might
have been seen so far in the majority of the tree taxa is (a) the response for species
with weak photoperiodism or chill control, or (b) a phenology that was pushed
by temperatures to the far end of phenology ‘windows’ controlled by genetically
controlled phenology. In the latter case, we should not see a further extension of
these trends, or the slowing of the trends should not be confused with a slowing of
warming (which may have other biological effects, see problem one). In the first
case, we should see community effects, with the photoperiod insensitive taxa taking
an advantage. Exotic taxa, as commonly grown in cities may track the climate,
whereas the native vegetation may not.
The second problem relates to predictions of future season length and the related
plant activities by using current trends in plant phenology and climate. Numerous
phenological observations, both direct and by remote sensing (see Chapter 4) have
documented that thewarming trends observed during the last century were associated
with earlier greening/flowering and later senescence of plants. However, what might
have been seen so far in the majority of the tree taxa is (a) the response for species
with weak photoperiodism or chill control, or (b) a phenology that was pushed
by temperatures to the far end of phenology ‘windows’ controlled by genetically
controlled phenology. In the latter case, we should not see a further extension of
these trends, or the slowing of the trends should not be confused with a slowing of
warming (which may have other biological effects, see problem one). In the first
case, we should see community effects, with the photoperiod insensitive taxa taking
an advantage. Exotic taxa, as commonly grown in cities may track the climate,
whereas the native vegetation may not.
การแปล กรุณารอสักครู่..
