Bud dormancy of plants has traditionally been explained either by physiological growth arresting conditions in the bud or by unfavourable environmental conditions, such as non-growth-promoting low air temperatures. This conceptual dichotomy has provided the framework also for developing process-based plant phenology models. Here, we propose a novel model that in addition to covering the classical dichotomy as a special case also allows the quantification of an interaction of physiological and environmental factors. According to this plant-environment interaction suggested conceptually decades ago, rather than being unambiguous, the concept of "non-growth-promoting low air temperature" depends on the dormancy status of the plant. We parameterized the model with experimental results of growth onset for seven boreal plant species and found that based on the strength of the interaction, the species can be classified into three dormancy types, only one of which represents the traditional dichotomy. We also tested the model with four species in an independent experiment. Our study suggests that interaction of environmental and physiological factors may be involved in many such phenomena that have until now been considered simply as plant traits without any considerations of effects of the environmental factors.

The importance of equine welfare has become more important in the last years. There is a need for welfare parameters, which help to define and measure the welfare of domestic horses. The importance of sleep on health and wellbeing is well-known in humans but has not yet been extensively studied in horses. It is known that horses sleep either non-REM-sleep or REM-sleep. Also, horses are able to partially sleep in a standing position. For REM-sleep they need to have muscle atony and lie down. Horses are easily disturbed while sleeping and many factors affect how much and how long horses spend sleeping. Horses are also able to postpone their REM-sleep for extensive periods of time, which directly effects their health and welfare. The aim of our study was to measure and analyze how the softness of the bedding in the lying areas affect the sleeping and resting behavior of horses. This thesis was part of the UNIHEPO initiative, which consisted of multiple studies around equine sleep. For our study we conducted a cross over study with sixteen (16) clinically healthy horses in the equine school Ylä-Savon ammattiopisto during fall 2022. The study included three treatments: the normal amount of bedding as the baseline, then thin (5 cm) bedding and thick (15 cm) of bedding. We recorded three periods: the baseline, and then two consecutive periods with half of the stalls having thick bedding and the other half thin. The duration of each treatment period was 21 days, respectively. We switched the treatments after the first period so that that each horse had both treatments. We recorded and analyzed the first two (2) and last two (2) nights of each period. The results were reported as seconds calculated from the median of the daily mean values. Only the data from the two treatments was analyzed for this thesis. The horses exhibited more resting behaviors and supported their necks longer in a sleeping position, when the bedding was thicker (p=0,002). There was no statistically significant difference between the treatments when lateral recumbency bout amounts or lying durations were analyzed, but the lying duration was longer. With thicker bedding the horses had a higher number of sternal recumbency bouts (p=0,013) and the bout duration was longer (p=0,001). Also, the total duration spent in sternal recumbency was higher on thicker bedding (p=0,002). Surprisingly we noticed rolling behavior after lying bouts almost solely on thicker bedding (p=0,004). There were also some tendencies for correlation between the height of the horses, lying bouts and bedding thickness. Our research provided us with valuable information on the factors affecting the sleeping and resting behavior of horses. At the same time the need for further research was highlighted. Still, our results reinforce the scientific knowledge, which is crucial in developing and promoting equine welfare.