1Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen, Denmark.
Pastoralisme Conseil, 30 chemin de Jouanal, 82160 Caylus, France.
Commun Biol. 2019 Apr 23;2:133. doi: 10.1038/s42003-019-0383-9. eCollection 2019.
Dryland ecosystems comprise a balance between woody and herbaceous vegetation. Climate change impacts rainfall timing, which may alter the respective contributions of woody and herbaceous plants on the total vegetation production. Here, we apply 30 years of field-measured woody foliage and herbaceous mass from Senegal and document a faster increase in woody foliage mass (+17 kg ha yr) as compared to herbaceous mass (+3 kg ha yr). Annual rainfall trends were partitioned into core wet-season rains (+0.7 mm yr), supporting a weak but periodic (5-year cycles) increase in herbaceous mass, and early/late rains (+2.1 mm yr), explaining the strongly increased woody foliage mass. Satellite observations confirm these findings for the majority of the Sahel, with total herbaceous/woody foliage mass increases by 6%/20%. We conclude that the rainfall recovery in the Sahel does not benefit herbaceous vegetation to the same extent as woody vegetation, presumably favoured by increased early/late rains.
旱地生态系统由木本和草本植被之间的平衡构成。气候变化影响降雨时间，这可能会改变木本和草本植物对总植被产量的各自贡献。在这里，我们应用了 30 年来从塞内加尔实地测量的木本叶片和草本生物量，并记录到木本叶片质量的增长速度（+17kg/ha/yr）明显快于草本生物量（+3kg/ha/yr）。将年降雨量趋势分为核心湿季降雨（+0.7mm/yr），支持草本生物量的微弱但周期性（5 年周期）增加，以及早/晚降雨（+2.1mm/yr），解释了木本叶片质量的大幅增加。卫星观测结果证实了萨赫勒大部分地区的这一发现，总草本/木本叶片质量分别增加了 6%和 20%。我们的结论是，萨赫勒的降雨恢复并没有使草本植被像木本植被那样受益，这可能是由于早/晚降雨增加而导致的。
