Deforestation can compromise ecological processes and biotic interactions, including the host–parasite relationship. While some parasites infect only one host, others require multiple hosts to complete their complex life cycles. In this context, different parasites may have different demands and traits and may have specific responses to habitat degradation. Here, we tested whether forest cover has different effects on different frogs' parasites, as chytrid (Batrachochytrium dendrobatidis; Bd) and helminths (Platyhelminthes and Nematoda). We collected data on two stream frog species (Crossodactylus caramaschii and Crossodactylus schmidti) from nine sites in the Brazilian Atlantic forest, with forest cover ranging from 20% to 99%. Bd presence and load increased with decreasing forest cover, but the opposite was observed for nematodes. Load of monoxenous and heteroxenous helminths increased with forest cover. We suggest that variations in potential host diversity, microclimate conditions, and host immune response may be responsible for the contrasting patterns found for micro‐(Bd) and macroparasites (helminths, except Platyhelminthes). Our work brings evidence of how habitat reduction can affect host–parasite relationships, including infection with the pathogen responsible for hundreds of global species extinctions.

中文翻译：

---

在森林覆盖率较小的景观中，洪流青蛙的宏观寄生虫较少，但壶菌的感染率较高

森林砍伐会损害生态过程和生物相互作用，包括宿主与寄生虫的关系。一些寄生虫仅感染一个宿主，而另一些则需要多个宿主才能完成其复杂的生命周期。在这种情况下，不同的寄生虫可能具有不同的需求和特征，并且可能对生境退化产生特定的反应。在这里，我们测试了森林覆盖率是否对不同的青蛙寄生虫有不同的影响，如壶菌（Batrachochytrium dendrobatidis ; Bd）和蠕虫（Platyhelminthes和Nematoda）。我们收集了两种蛙类数据（Crossodactylus caramaschii和Crossodactylus schmidti）来自巴西大西洋森林的9个地点，森林覆盖率从20％到99％不等。Bd的存在和负荷随森林覆盖率的降低而增加，但对于线虫却观察到相反的情况。随着森林的覆盖，单性和异性蠕虫的负荷增加。我们建议潜在宿主多样性，微气候条件和宿主免疫反应的变化可能是导致微量（Bd）和大型寄生虫（蠕虫，除侧柏蠕虫除外）的对比模式的原因。我们的工作为减少栖息地如何影响寄主与寄生虫之间的关系提供了证据，包括感染导致数百种全球物种灭绝的病原体。