Forest degradation is widely assumed to drive a monotonic decline in belowground functioning, yet plant-soil feedbacks may transiently buffer stress. We tested this idea by quantifying the rhizosphere effect (RE), the percentage difference between rhizosphere and bulk soil, for soil carbon (C), nitrogen (N) and phosphorus (P) pools, enzymatic activities, and microbial biomass across four degradation stages in three types of shelterbelt forests. We found that REs generally increased or remained stable from undegraded to mild-moderate degradation stage and then declined sharply at severe degradation stage. This nonlinear pattern was consistent across species but differed in amplitude and timing, with Populus thevestina showing the largest early increases, Populus alba maintaining RE longer before decline, and Populus popularis reaching negative REs for SOC and microbial biomass phosphorus at the severe degradation stage. Early positive RE coincided with lower pH and higher water-soluble organic carbon (WSOC), soil water content (SWC), and enriched available N (NH4+ and NO3-) in rhizospheres, conditions that stimulate microbial activities and nutrient turnover. As degradation intensified, the significant differences between rhizosphere and bulk soil properties contracted and eventually disappeared, reflecting a decline of plant-soil feedbacks likely driven by reduced root exudation. Random-forest and redundancy analyses highlighted rhizosphere P, rhizosphere N, bulk soil WSOC, rhizosphere SWC, and bulk-soil stoichiometry as the most influential factors of these shifts, consistent with a transition from compensatory stimulation to functional collapse beyond a critical tipping zone. This study provides the first field evidence that rhizosphere functioning responds nonlinearly to forest degradation. Recognizing this transient compensatory phase advances our understanding of ecosystem belowground resilience and can inform the intervention windows for dryland forest restoration.