Overall this review is very well done and quite comprehensive.
I have just a couple of issues to raise:
1. Page 21 (line 476). The idea that increased moisture in the air
will reduce the risk of frost is incorrect, and not something stated or
supported by the listed reference (Schwartz and Karl 1990). Indeed,
Schwartz (1996) explicitly shows that last spring frost dates ARE
NOT correlated with the increased air moisture changes associated
with the onset of plant transpiration.
Last frost events are usually driven by a single daily synoptic
weather situation, which overwhelms any tendency for reduced
cooling caused by a slight increase of moisture in the air.
2. Pages 32-36 “Modeling and Forecasting Phenology” section,
esp. lines 800-806. This section neglects mention of large clonal
data bases (such as the one in Europe used by Menzel [1999], and
another used in North America by Schwartz et al. [2006] and earlier
references) to develop phenological models.
The most egregious part is the lack of discussion of the role
that phenological models developed from clonal plants can play
in disentangling the impacts of genetics and climate on species