How conservation trade-offs translate into biased conservation outcomes: A case study from China

Trade-offs among conservation features often result in insufficient representation of certain species or regions in conservation planning. Previous studies have documented such trade-offs, but how these trade-offs translate into biased conservation outcomes remains unclear. Here, we compiled a dataset of 2733 terrestrial vertebrate species and 11 ecosystem services in China and conducted conservation planning across four approaches: (1) species richness (SRic), (2) ecosystem service (ES), (3) corrected weighted endemism (CWE), and (4) target-based complementary algorithm (TB). We made comparisons based on their spatial prioritization and feature coverage and analyzed the reason behind different conservation outcomes. Results showed that SRic and ES approach favored eastern regions, while CWE and TB approach preferred the west. The TB approach achieved the highest species target attainment, yet it captured substantially less ecosystem service coverage than the ES approach. Species with wide range, high species richness within their range, and easterly range centroids were consistently better conserved, while amphibians were consistently less effectively conserved. Regions with high SRic and ES values usually possessed ample water and high primary productivity, whereas regions with high CWE and TB values featured complex topography. Strong synergy emerged with sufficient water, high productivity, complex topography and stable climate. Our results demonstrated that trade-offs among conservation objectives generate systematic biases in conservation outcomes, which are associated with species characteristics and environmental conditions. To achieve Kunming-Montreal Global Biodiversity Framework's 30% target, integrating multiple conservation perspectives and directing resources toward easily overlooked features and regions are essential for building a robust conservation network.