Table 1.
Characteristics of beech, oak and alder stands varying in age.
Abbreviations: DBH–diameter at breast height, H–tree height, G–total basal area.
Fig 1.
Mean fine root biomass (±SE) from 0–30 cm soil depth for beech, oak and alder stand chronosequences.
Analysis of variance was performed to show significance of differences among stand chronosequences for total fine root biomass. Same letters in Tukey’s test show lack of differences among mean values of fine root biomass of beech, oak and alder stands.
Fig 2.
Relationships between stand age and fine root biomass expressed on a stand area basis (g m-2) for 0–30 cm soil depth for beech, oak and alder chronosequences.
Relationships were modeled using Generalized Additive Models. Shaded area represents the confidence interval of GAM. Points represent mean values for each tree stand, raw datapoints are available in S1 File.
Fig 3.
Relationships between stand age and fine root biomass for the average individual tree in each stand (kg tree-1) for 0–30 cm soil depth for beech, oak and alder chronosequences, modeled by Generalized Additive Models (GAM).
The mean individual tree root biomass was calculated by dividing the respective fine root biomass for each stand per ha (shown in S1 Table) by the number of trees in the stand per ha (shown in Table 1). Shaded area represents the confidence interval of GAM. Points represent mean values for each tree stand, raw datapoints are available in S1 File.
Fig 4.
Relationships between stand age and fine root morphological traits for 0–15 cm and 16–30 cm soil depths for the beech stand chronosequence.
Relationships were modeled using a Generalized Additive Model. Shaded area represents the confidence interval of GAM. Points represent mean values for each tree stand, raw datapoints are available in S1 File.
Fig 5.
Relationships between stand age and fine root length, surface area, volume and number of root tips for the average individual tree in each stand for 0–30 cm soil depth for beech, oak and alder chronosequences modeled by Generalized Additive Models (GAM).
The mean individual fine root indices were calculated by dividing the particular root traits values for each stand per ha (shown in S2, S3 and S4 Tables) by the number of trees in the stand per ha (shown in Table 1). Shaded area represents the confidence interval of GAM. Points represent mean values for each tree stand, raw datapoints are available in S1 File.
Fig 6.
Relationships between stand age and fine root morphological traits for 0–15 cm and 16–30 cm soil depths for the oak stand chronosequence.
Relationships were modeled using Generalized Additive Models. Shaded area represents the confidence interval of GAM. Points represent mean values for each tree stand, raw datapoints are available in S1 File.
Fig 7.
Relationships between stand age and fine root morphological traits for 0–15 cm and 16–30 cm soil depths for the alder stand chronosequence.
Relationships were modeled using Generalized Additive Models. Shaded area represents the confidence interval of GAM. Points represent mean values for each tree stand, raw datapoints are available in S1 File.