In addition, the passability or grazing of the areas can be restricted by heavy rainfall.
Climate adaptation in agriculture and forestry (Thünen Working Paper 86):
In principle, positive effects on the yield can be expected for grassland due to climatic consequences such as an earlier start of the vegetation period with higher temperatures and an overall longer vegetation period as well as higher CO2 concentrations. On the other hand, extreme weather events such as droughts have negative effects on the yield and quality of grassland. Higher variability of precipitation is also expected to reduce yields as a result of a shift in plant groups towards lower grass content (Grant et al., 2014). Nevertheless, a change in plant community towards a higher herb content under CO2 enrichment was observed (Teyssonneyre et al., 2002).
While only slight yield increases are expected for N-fertilized grassland on fresh, heat-limited sites until the end of the century due to the increase in temperature, yield increases of up to 20% were possible for white clover in monoculture, taking into account the CO2 effect (Hebeisen et al., 1997). In addition, higher CO2 concentrations led to a lower crude fibre content and thus to a better digestibility of grassland, while the N content and, as a consequence, the crude protein content of grasses generally decreased (Weigel and Manderscheid, 2005).
Changes in the nutrient supply and availability as well as the feed value must therefore be expected. Pathogenic risks must also be considered. As a consequence of increased summer drought, an increased infestation of ryegrass seed propagation stands with black rust was observed. Infestation with crown rust and bacterial wilt also increasingly leads to damage of economic significance.
https://literatur.thuenen.de/digbib_extern/dn059699.pdf (s. chapter 8, p. 45)