一个阅读中的推理问题

以希UID: 3946411

Ecologists had assumed that trees in the consistently warm tropics grew at a slow but steady rate, unvarying from year to year. However, a study at La Selva, Costa Rica, showed that trees grew less in hotter years and more in cooler ones: between 1984 and 2000, dramatic differences occurred in the six species of trees studies, with trees adding twice as much wood in some cooler years as they did in the scorching El Nino year of 1997-1998. Because tree growth is an index of the balance between photosynthesis, in which trees absorb carbon dioxide (CO2) from the atmosphere and release oxygen, and respiration, in which the opposite occurs, the La Selva data were the first hint that rapidly rising global temperatures, driven by human-generated emissions of CO2, may be pushing tropical forests to release more CO2, thereby intensifying global warming. This raised serious questions about a popular theory that tropical forests act as a sponge, soaking up much of the excess CO2 that humans pump into the atmosphere. The La Selva data are consistent with a model of global CO2 flux developed by Keeling, who concluded that the amount of CO2 taken up in tropical landmasses rose in cooler years and fell in hotter ones, accounting for year-to-year changes in the amount of CO2 that stays in the atmosphere.

题目没有问题，但是我对其中的推理不太理解。三个加粗的地方：
1. temperature↑ -> grow↓
2. temperature↑ -> CO2↑
3. temperature↑ -> CO2↓
这里2，3似乎是矛盾的，想请问大家是哪里的理解出了问题，谢谢！

Orion_ChangUID: 3582304

2是CO2 released into the atmosphere
3是CO2 taken up in tropical landmasses (namely, wood)

以希UID: 3946411

Orion_Chang 发表于 2019-6-5 19:25
2是CO2 released into the atmosphere
3是CO2 taken up in tropical landmasses (namely, wood)

这里的taken up是指“固碳”的意思吗？

Julian2323UID: 2859319

你前两个理解都是正确的，第三处的意思，在较冷的年份接受的／处理的co2上升，较热年份下降，也就是较冷年份固碳多，较热年份固碳少

以希UID: 3946411

Julian2323 发表于 2019-06-05 23:34你前两个理解都是正确的，第三处的意思，在较冷的年份接受的／处理的co2上升，较热年份下降，也就是较冷年份固碳多，较热年份固碳少

谢谢回答，之前不知道take up有absorb的意思，所以理解错了。