Soru

Passage A
For decades, classical ecologists viewed the forest primarily as a battleground where individual trees competed fiercely for limited resources such as sunlight, water, and soil nutrients. This Darwinian paradigm shifted dramatically in the late twentieth century with the discovery of common mycorrhizal networks. These vast, hidden underground webs of fungal mycelium physically connect the root systems of diverse plant species, facilitating a complex system of exchange. In groundbreaking experiments using radioactive isotopes, scientists traced the flow of nutrients and definitively showed that resources, particularly carbon, travel from older, deeply rooted trees in the canopy to younger, shaded seedlings through these fungal pathways. In this symbiotic relationship, the fungi receive photosynthesized sugars from the trees; in return, the fungi's sprawling networks act as massive extensions of the trees' root systems, significantly increasing the plants' capacity for water and mineral absorption. Proponents of this view argue that forests function less as isolated competitors and more as cooperative superorganisms. In this model, established "hub trees" actively nourish the vulnerable next generation, thereby ensuring the long-term resilience and biodiversity of the entire forest community.

Passage B
The popular narrative of the forest as a cooperative, egalitarian utopia—intimately connected by a benevolent fungal network—has increasingly captivated the public imagination. However, a closer, more rigorous examination of the ecological data suggests a far less altruistic reality. While it is an established physical fact that carbon and other resources can and do move between distinct trees via connecting fungal hyphae, interpreting this transfer as intentional, cooperative sharing orchestrated by the trees is highly problematic. Fungi are independently evolved organisms driven by their own evolutionary imperatives, primarily securing their own survival and reproduction. It is far more likely that the fungi are selfishly redistributing resources to optimize the health of their own sprawling networks rather than acting as passive conduits for tree-directed charity. When a shaded seedling receives transferred carbon, it is likely because the fungus is investing in a new, potential host to secure its own future carbon supply, not because the larger tree is actively "nursing" its neighbors. Furthermore, these exact same underground networks can seamlessly facilitate the spread of allelopathic chemicals—harmful toxins produced by one tree specifically to inhibit the growth of surrounding rivals. Thus, the underground ecosystem is less a cooperative commune and more a highly competitive marketplace where fungi dictate the terms of trade.

Based on the passages, which one of the following details is explicitly affirmed by the authors of both Passage A and Passage B?