Data from: Contrasting impacts of land use change on phylogenetic and functional diversity of tropical forest birds

1.Biodiversity conservation strategies increasingly target maintaining evolutionary history and the resilience of ecosystem function, not just species richness (SR). This has led to the emergence of two metrics commonly proposed as tools for decision making: phylogenetic diversity (PD) and functional diversity (FD). Yet the extent to which they are interchangeable remains poorly understood.

2.We explore shifts in and relationships between FD and PD of bird communities across a disturbance gradient in Borneo, from old-growth tropical forest to oil palm plantation.

3.We show a marked decline in PD, and an increase in phylogenetic mean nearest taxon distance (MNTD) from forest to oil palm, in line with declining SR across the gradient. However, phylogenetic mean pairwise distance (MPD) is constrained by forest logging more than by conversion to oil palm, taking account of SR.

4.The decline in FD across the gradient is less severe than in PD, with all metrics indicating relatively high trait diversity in oil palm despite low SR, although functional redundancy is much reduced. Accounting for SR, levels of functional over- or under-dispersion of bird communities are strongly coupled to habitat disturbance level rather than to any equivalent phylogenetic metric.

5.Policy Implications. We suggest that while phylogenetic diversity (PD) is an improvement on species richness as a proxy for functional diversity (FD), conservation decisions based on PD alone cannot reliably safeguard maximal FD. Thus, PD and FD are related but still complementary. Priority setting exercises should use these metrics in combination to identify conservation targets.

1. 生物多样性保护策略日益以维持演化历史与生态系统功能韧性为目标，而非仅关注物种丰富度（species richness, SR）。由此催生了两类常被提议作为决策工具的指标：系统发育多样性（phylogenetic diversity, PD）与功能多样性（functional diversity, FD）。但目前学界对二者的可互换程度仍知之甚少。
2. 本研究聚焦婆罗洲地区沿干扰梯度（从原始热带森林到油棕种植园）的鸟类群落，探讨其功能多样性与系统发育多样性的变化模式及二者间的关联。
3. 研究结果显示，从森林到油棕种植园的梯度中，系统发育多样性显著下降，而系统发育平均最近分类单元距离（phylogenetic mean nearest taxon distance, MNTD）则呈上升趋势，这与梯度上物种丰富度的下降趋势一致。但在控制物种丰富度的前提下，系统发育平均成对距离（phylogenetic mean pairwise distance, MPD）受森林采伐的影响程度大于转为油棕种植园的影响。
4. 沿该梯度的功能多样性下降幅度则小于系统发育多样性：尽管油棕种植园的物种丰富度较低，但所有指标均显示其功能性状多样性仍处于较高水平，不过功能冗余度大幅降低。在控制物种丰富度的前提下，鸟类群落的功能过分散与功能欠分散水平，与栖息地干扰程度紧密相关，而非与任何对应的系统发育指标相关。
5. 政策启示。本研究认为，尽管系统发育多样性作为功能多样性的替代指标，相较于物种丰富度已有进步，但仅基于系统发育多样性制定的保护决策，无法可靠地保障功能多样性的最大化。由此可见，系统发育多样性与功能多样性虽存在关联，但二者仍具有互补性。在开展保护优先级划定工作时，应结合使用这两类指标以确定保护目标。