However, other studies in turbot have shown positive allometry associated with temperature [ 23], negative allometric growth being thus observed in late summer and autumn (temperature around 22°C), while positive allometric growth holds up in winter and spring (temperature around 7-10°C 7-10°C
Indeed, a tendency for earlier timing of breeding at higher spring temperature has been observed in several bird species (Dunn and Winkler 2010; Charmantier and Gienapp 2014), including tree swallows (Dunn and Winkler 1999; Winkler et al. 2002; this study).
These were: for birth date, total autumn rainfall (mm) between September and December in the autumn of gestation [ 55]; for birth weight, the average spring temperature (°C) between February and April [ 55]; and for first year survival, total winter rainfall (mm) between November and January of the first winter of life [ 49, 54].
In Thoreau's time, the average spring temperature was 42 degrees and the average date of first flowering of the 32 species in the study was May 15.
They calculated the average first flowering date of all the species over time as well as the average flowering date for individual species, then compared those dates with the mean spring temperature at the study sites for each year.
The authors found that, for both time periods, the early spider orchid's peak flowering time shifted identically and precisely in response to changes in the average spring temperature: they found that flowering times occurred six days earlier for every degree Celsius increase in average springtime temperatures.
In conclusion, spring temperature and hydrochemistry alone may not always correctly reflect the deep geothermal potential of an area.
On the other hand, an earlier start involves risks of growth cessation due to low spring temperature.
The study found that both the herbarium data-set and the more recent field observations showed that for every 1°C (1.8°F) increase in the average spring temperature, the orchids flowered six days earlier.
Spring temperature is constantly increasing during the period 2021 2100 and the corresponding increment ranges for the four RCM GCM combinations are 2.3 3.2 °C (HA), 1.8 4.4 °C (RAE), 0.3 3.2 °C (REE) and 0.6 2.5 °C (RH).
Based on the information of xylogenesis we present an initial insight on the effect of spring temperature on the onset of growth and the relative role of vegetation period on seasonal growth when drought periods are present or missing.
