As a fast-growing timber tree species with a wide cultivation area, poplar is facing the problem of declining economic benefits under long-term monoculture. Intercropping provides an effective solution. Using Illumina Miseq sequencing, we analyzed soil microbiomes under four patterns: poplar monoculture, and intercropping with amorpha fruticosa, black locust, or cassia seed. The results showed that the Alpha diversity index of intercropping area was significantly higher than that of single planting poplar area under intercropping and monoculture conditions. In the intercropping area, the highest species richness was the intercropping of poplar and black locust, and the lowest was the intercropping of poplar and amorpha fruticosa. The dominant microorganisms in the intercropping mode were Vicinamibacterales, and the fungi were Alternaia and Enterocarpus. In the single planting poplar area, a large number of bacteria gathered in the soil were Dongia and Alphaproteobacteria, and fungi were Fusarium and Mortierella. Functional prediction results showed that the biosynthetic function of ansamycin was the highest in the bacterial community. In the intercropping area, the functional abundance of methanol oxidation, sulfate respiration, sulfate compound respiration, nitrate denitrification, nitrite denitrification, and nitrous oxide denitrification was higher than that in the single planting poplar area. On the contrary, the abundance of methanotrophy function is lower than that of single planting poplar area. In the fungal community, the functional abundance of animal pathogens and the animal pathogen–dung saprotroph–endophyte–plant saprotroph–soil saprotroph–wood saprotroph group in the monoculture poplar area was higher than that in the three intercropping areas. In summary, the intercropping mode of poplar is better than the monoculture mode, and the species richness is the highest when poplar and black locust are intercropped. Therefore, the intercropping pattern of poplar and other tree species improved microbial community. This provides some theoretical guidance for the subsequent solution of continuous cropping obstacles in poplar.

Balancing ecological conservation with agricultural production in protected areas remains a critical challenge, particularly regarding the nexus of food, water, land, and ecosystems (FWLE). Yet, the spatiotemporal trade-offs, synergies, and underlying drivers within the FWLE remain poorly understood. Focusing on the Henan Funiu Mountain National Nature Reserve (HFMNNR), we quantified water yield (WY), habitat quality (HQ), and food production (FP) using the InVEST model and statistical yearbook data. The XGBoost-SHAP framework was applied to dissect the key drivers and mechanisms governing the FWLE system. Results indicate a significant increasing trend in FP (2000–2020), contrasting with the unimodal (increase-then-decline) trajectories of HQ and WY. Pronounced trade-offs were identified between HQ and WY, and between HQ and FP. Topographic and vegetative factors predominated in shaping the spatial patterns of HQ and FP, whereas climatic factors dictated WY distribution. Specifically, HQ declined when NDVI fell below 0.87, population density surpassed 0.01, or slope was gentler than 7°. WY was constrained when precipitation dropped below 947 mm, actual evapotranspiration exceeded 752 mm, or temperature ranged between 12.5–16.2 °C. FP was suppressed under conditions of slopes > 7°, NDVI within 0–0.61 or 0.61–0.86, or DEM > 373 m. These findings underscore the necessity of spatially explicit management strategies grounded in spatial heterogeneity. We advocate for a multi-objective governance framework centered on HQ to harmonize production and ecological functions. Our findings provide critical insights for formulating policies aimed at sustainably managing protected areas facing similar ecological-production conflicts.