Balancing urbanization, agricultural production and ecological integrity: A cross-scale landscape functional and structural approach in China

Projecting land-use allocation under various scenarios can be useful for reconciling conflicts between urbanization, food security, and ecological integrity throughout landscapes, but existing approaches often fail to capture the interactions in land systems that occur across scales and within and between hierarchical jurisdictions of societal organization. This article introduces a cross-scale functional and structural approach for balancing trade-offs in landscape planning and sustainable land management at multiple levels, based on the principles of multifunctional suitability. Using Heilongjiang Province in China as a case, we simulate four landscape scenarios that progressively consider cross-scale and inter-regional trade-offs more broadly, as well as local suitability. In the business-as-usual (BAU) scenario, no multifunctionality objectives are considered at any level; in the own-provincial scale (OPS) scenario, intra-province multifunctionality objectives are considered; the national and provincial scales (NPS) scenario considers multifunctionality within and beyond the province; while the desired land-use (DLU) scenario balances cross-scale multifunctionality while also optimizing for local functional suitability. Promoting multifunctionality as desirable, and evaluated based on minimizing functional land loss, the DLU scenario significantly outperforms the BAU scenario. The results indicate that the DLU scenario outperforms BAU, OPL, and NPS in optimizing urban and cropland layout, and preserving ecosystem integrity. It reduces high-quality arable land loss by 6.5% and minimizes the impact on ecological function areas by 12%, surpassing the BAU scenario. In contrast to the OPS and NPS scenarios, the DLU scenario exhibits a 6% and 2% increase in population and economic agglomeration within the Harbin-Daqing-Suihua (HDS) city cluster, a pivotal component of the national urbanization strategy. Furthermore, it enhances grain production capacity in the national grain-producing area, the Sanjiang Plain (SJP), with 9% and 12% boosts, respectively. Additionally, the DLU scenario expands the ecologically significant area, showing a 3.6% and 1% improvement in the Greater and Lesser Khingan Mountains (GLKM), nationally vital ecological service function areas. These advantages of the DLU scenario are expected to become more pronounced over time. The novel theoretical approach and modelling framework introduced in this study can serve as inspiration elsewhere for reconciling future land-use trade-offs and planning decisions across scales.