Data from: A model for non-equilibrium metapopulation dynamics utilizing data on species occupancy, patch ages and landscape history

1. The distribution pattern of many species reflects the past rather than the current structure of landscapes. Consequently, species are most often not in equilibrium with the current landscape structure. Yet this is a well-known fact, there is no appropriate approach to estimate the colonization rate of non-equilibrium species based on only data on the species occurrence pattern in the landscape. 2. We present an approach to estimate the colonization rate of non-equilibrium metapopulations. The approach requires only data on species presence/absence among its patches (occurrence pattern), data on patch ages and data on the historic distribution of the patches in the landscape. By estimating the past occurrence patterns and colonization events leading to the current pattern of occupied and non-occupied patches, we estimate the colonization rate, including the dispersal kernel. We also show how to estimate effects of local patch conditions and how to include an independent estimate of the local extinction rate based on other data. We use nine epiphytic lichen species confined to beech trees to illustrate the method. 3. Five species had restricted dispersal range, between 200 and 4700 m, and their colonization rate decreased with increasing fragmentation. Species colonization rates were related to niche width. Among the demographic parameters, the force of colonization was more important than the dispersal range in explaining the colonization rates. Local patch conditions did not explain the colonization probability of any species. In metapopulation projections that did not account for restricted dispersal range, higher future metapopulation sizes were projected. 4. Synthesis. The presented approach uses data on only species occurrence, patch age and landscape history to estimate the species colonization rate and dispersal kernel. It can also utilize independent data on local extinction rate. Rather than identifying factors explaining the occurrence pattern, the model estimates the rate of change in the occurrence pattern. This dynamic modelling allows testing general and applied questions on the dynamics or viability of metapopulations of sessile species. The approach is applicable for species whose distribution pattern reflects the past rather than the current landscape structure, e.g. certain epiphytes and ground-floor plants.

1. 许多物种的分布格局所反映的是历史景观特征，而非当前的景观结构。因此，多数物种往往并未与当前的景观结构达到平衡状态。尽管这已是学界公认的事实，但目前仍缺乏仅依托景观内物种出现格局数据，来估算非平衡物种定殖率（colonization rate）的合适方法。
2. 本研究提出了一种估算非平衡集合种群（metapopulation）定殖率的方法。该方法仅需三类数据：物种在各斑块（patch）中的存在/缺失数据（即出现格局）、斑块年龄数据，以及景观内斑块的历史分布数据。通过反推历史出现格局以及促成当前斑块占据与未占据格局的定殖事件，我们可估算定殖率，包括扩散核（dispersal kernel）。此外，本研究还阐明了如何估算局地斑块条件的效应，以及如何基于其他数据纳入局地灭绝率的独立估算值。我们以9种仅生存于山毛榉树上的附生地衣（epiphytic lichen）为例，对该方法进行了演示。
3. 有5个物种的扩散范围受限，介于200至4700米之间，且其定殖率随景观破碎化程度加剧而下降。物种定殖率与生态位宽度（niche width）相关。在种群统计参数（demographic parameter）中，定殖力相较于扩散范围，对定殖率的解释度更高。局地斑块条件无法解释任一物种的定殖概率。在未考虑扩散范围受限的集合种群预测中，未来集合种群规模的预测值会偏高。
4. 综合分析。本研究所提出的方法仅依托物种出现数据、斑块年龄数据与景观历史数据，即可估算物种的定殖率与扩散核。该方法亦可纳入局地灭绝率的独立估算数据。该模型并非用于解析解释物种出现格局的影响因子，而是用于估算出现格局的变化速率。这种动态建模方法可用于检验固着物种（sessile species）集合种群动态或存续性相关的理论与应用问题。该方法适用于分布格局反映历史而非当前景观结构的物种，例如部分附生植物与地表植物。