Beyond protected areas: The synergistic role of forest territorial planning in safeguarding tree diversity

Forest territorial planning (FTP) provides a critical, yet under-evaluated, spatial strategy that may complement biodiversity conservation of protected areas (PAs). To address the recognized shortfalls of PAs in achieving comprehensive biodiversity targets, we evaluated the effectiveness of integrating FTP with the current high-protection PAs (IUCN categories I–IV) in Argentina. Specifically, we aimed to: assess the representativeness of tree species richness and distribution within existing PAs; quantify FTP's complementary contribution to habitat conservation; and analyze the combined role of PAs and FTP in protecting species across varying endemism levels and historical habitat loss. We found a significant spatial mismatch between existing PAs and tree biodiversity: while regions like the Atlantic Forest and Yungas host the highest richness, only 23% of high-biodiversity areas fall within PAs. On average, 8.71% of species ranges overlap with the PAs. Furthermore, PAs' representativeness dropped to 3% for highly endemic species, while woody vegetation changes have driven an 11% average loss in species ranges. The integration of PAs with FTP mitigated these conservation gaps. Strict conservation and sustainable use zones increased average species range representativeness to 18% and 58%, respectively, although sustainable use zones reflects potential conservation coverage rather than guaranteed protection effectiveness. FTP also substantially increased representativeness across endemism degrees and range losses. A synergistic approach combining PAs with adaptive FTPs offers a strategic opportunity to rectify spatial mismatches in species protection. Incorporating FTP, particularly when supported by appropriate socioeconomic measures in sustainable-use zones, could provide the most viable path for ensuring long-term protection of forests.