This paper uses data from previous worldwide myxomycete surveys to determine the controls on the occurrence of myxomycete species, and on species assemblages. The main findings are as follows. The effect of substrate pH can be modelled, in that each species has a preferred pH value relative to the mean of a survey; errors from the model are 0.2 pH units. The substrate physical properties, evaluated by subjective hardness, showed no correlation with pH measurements. Hence, myxomycete species seem to have distinct ecological niches in substrate, with preferred pH and preferred physical properties. Comparison of the species found from the liana stem substrate shows that the species association does not change within angiosperm forests. Further, the species association is the same as that found in other angiosperm litter substrates: twigs on trees or on the ground, and leaves. This and a previous finding are consistent with similar ecological environments around the world having the same myxomycete species association within sampling error. In mixed angiosperm forests around the world the pH of un-decayed wood is ~4.9, and for decayed wood and tree litter is ~6.5 in tropical latitudes, and ~5.5 at 35° latitude, so on decaying the change in pH varies with latitude.

本文使用来自先前全球粘菌丝调查的数据来确定对粘菌丝物种的发生和物种组合的控制。主要发现如下。可以模拟底物pH的影响，因为相对于调查的平均值，每个物种都有一个优选的pH值。该模型的误差为0.2 pH单位。通过主观硬度评估的底物物理性能与pH测量值无关。因此，粘菌种似乎在底物中具有独特的生态位，具有优选的pH和优选的物理性质。从藤本植物茎基质中发现的物种的比较表明，被子植物森林中的物种关联没有改变。此外，物种关联与其他被子植物垫料中的物种关联相同：树枝在树上或地面上和树叶上。这一发现和先前的发现与世界范围内在采样误差内具有相同的粘菌种物种关联的相似生态环境相一致。在世界各地的被子植物混交林中，未腐烂木材的pH值约为4.9，而对于腐朽的木材和树木凋落物，在热带纬度中的pH值约为6.5，在35°纬度时为5.5，因此，腐烂的pH值随纬度的变化而变化。