Can Grazing Moderate Climatic Effects on Herbage Nutritional Quality?

Guy Dovrat,Zalmen Henkin,Tova Deutch,Haim Gorelik,Serge Yan Landau,Efrat Sheffer

doi:10.3390/agronomy11040700

Guy Dovrat, Zalmen Henkin + Show 4 more

Open Access

https://doi.org/10.3390/agronomy11040700

Copy DOI

Abstract

In Mediterranean grasslands, the composition of vegetation and its nutritional quality for animals are strongly affected by the climatic conditions prevailing during winter and spring. Therefore, these seasonal ecosystems provide an opportunity to examine how variability in climatic conditions affects the regeneration and quality of pasture vegetation. The intensity of grazing in this seasonal system can moderate, or alternatively exacerbate, climatic effects on the nutritional quality of the vegetation. Herein, we analyzed the interactive effects of climate variables, grazing intensity, and grazing exclusion on herbage quality parameters using long-term vegetation and climate data collected during 2005–2018 from an extensive experiment in Galilee, Israel. We evaluated the contribution of different climate variables to the prediction of herbage quality parameters. Our results showed that climate variables have a dramatic effect on herbage quality and that this effect interacts with grazing intensity. Herbage quality improved in temperate rainy years compared to warm and dry years. High grazing intensity improved herbage quality under temperate climate conditions, but this effect was moderated or completely disappeared as winter conditions become warmer and drier. The results of the study foresee negative effects of warming and drying on the carrying capacity of natural pastures.

Highlights

Global climate change poses a challenge for predicting short- and long-term ecosystem functions, with respect to estimating the services provided by ecosystems to humans [1,2] and predicting the threats expected from the increased sensitivity of these ecosystems [3,4]
Multi-year (2005–2018) data set of herbage quality and meteorological data, we examined the effects of different annual and seasonal climate variables on different parameters that define the nutritional quality of vegetation
The models that included the effect of maximum daily temperature in winter combined with grazing treatments were most parsimonious for neutral detergent fiber (NDF) (R2 = 0.40), crude protein content (R2 = 0.44), and digestibility (R2 = 0.33) of the vegetation (Tables S2–S5)

Summary

Introduction

Global climate change poses a challenge for predicting short- and long-term ecosystem functions, with respect to estimating the services provided by ecosystems to humans [1,2] and predicting the threats expected from the increased sensitivity of these ecosystems [3,4]. Regional and global models predict an increase in temperature and a decrease in rainfall amounts, as well as increased frequency of extreme events [9,10,11] The latter is expected to strongly influence vegetation composition and function [12,13]. In recent decades, the climate in the eastern Mediterranean Basin has become more arid in most regions [14] These expected climatic trends will have direct effects on plant physiology at the individual plant level [15,16,17] and on the composition and function of the vegetation at the plant community level [18,19]. Changes in vegetation composition include species turnover and shifts in the abundance and cover of plant species [20,21]

Methods

Results

Discussion

Conclusion