Relationships between autotrophic respiration (AR) and heterotrophic respiration (HR) and environmental factors across different aged stands of <i>Pinus sylvestris</i>.

<p>The relationships are shown between autotrophic respiration (AR) and heterotrophic respiration (HR) and soil temperature (ST) for ∼15-year-old (a), ∼35-year-old stands (e), between soil water content (SWC) and HR₁₅ for ∼15 years (b) and ∼35 years (f); between SWC and AR₁₅ for ∼15-year-old (c) and ∼35-year-old stands (g); between NDVI and AR₁₅ for ∼15-year-old stand (d), and between NDVI and AR for ∼35-year-old stands (h) of <i>Pinus sylvestris</i>. The data in the ∼25-year-old stand were absent because of the artificially damaged collars for separating AR and HR during the experiments.