A concept is discussed which links radial growth over a feedback loop …

• Abstract
• Introduction
• Materials and methods
• Results
• Discussion
• References
• Figures
• Tables

Biology Articles » Bioclimatology » Intra-annual radial growth and water relations of trees: implications towards a growth mechanism » Tables

Tables

- Intra-annual radial growth and water relations of trees: implications towards a growth mechanism

Table 1. Characteristics of the three species investigated at Salgesch and Jeizinen

Table 2. Mean daytime values (6–20 h) of microclimatic factors at Salgesch (Sa) and Jeizinen (Je), Switzerland: temperature (T_Air), solar radiation (R_N), vapour pressure deficit (VPD), soil water potential (_Soil) (seasonal minimum in brackets) and sum of rain (24 h) over the vegetation period (1 April to 30 September)

TAir (°C) RN (W m–2) VPD (kPa) Soil (kPa) Rain (mm) Sa Je Sa Je Sa Je Sa Je Sa Je 2002 18.2 – 387 – 0.86 – –82 (–283) – 482 – 2003 21.1 18.6 407 407 1.32 1.05 –186 (–448) –120 (–450) 258 204 2004 18.4 15.9 385 389 1.03 0.82 –118 (–324) –105 (–327) 252 185

Table 3. Microclimatic, morphological, and physiological factors, their assessment methods, locations and number of sensors (N) in the plot investigated at Salgesch (Sa) and Jeizinen (Je), Switzerland (tree labels in brackets)

Factor and abbreviation Method Location and height above-ground (tree label) N Net radiation Rn CM3, Kipp & Zonen, NL Sa and Je, outside vegetation: 2 m 2 Inside vegetation: 1–2 m 3 Rain Rain Tipping bucket, Young, USA Sa and Je, outside vegetation: 2 m 2 Air humidity, temperature, and vapour pressure deficit RH Hygroclip S, Rotronic, CH Sa and Je, outside vegetation: 2 m 2 TAir Calculated from RH and T Inside vegetation: 0.3–8 m 6 VPD Soil water potential Soil EQ2, Delta-T Devices, UK Sa, outside vegetation: –0.15 m 1 Sa and Je, inside vegetation: –0.15 m 5 Stem cores Puncher, WSL, CH Sa: Quercus: (2233, 2265) 0.3 m 2 Pinus: (2205, 2208) 0.3 m 2 Je: Quercus: (6236, 6267) 0.6 m 2 Pinus: (6239, 6281) 0.7 m 2 Picea: (6269, 6283) 0.4 m 2 Stem radius changes (stems) R Point dendrometer ZB01, IPS University of Bern, CH Sa: Quercus: (2274, 2264, 2265, 2268, 2198) 0.3 m 5 Pinus: (2254, 2208) 0.3 m 2 Je: Quercus: (6236, 6267) 0.6 m 2 Pinus: (6281, 6282) 0.8 m 2 Picea: (6269, 6283) 0.5 m 2 Sap flow of twigs SGB, Dynamax, USA Sa: Quercus: (2263, 2265, 2267, 2268, 2274) 0.5–3 m 5 Pinus: (2199, 2208) 1–1.5 m 2 Je: Quercus: (6235, 6237) 1.5–2.5 m 2 Pinus: (6239) 1–4 m 2 Picea: (6269) 0.5–8 m 2

Table 4. Phenological observations for Quercus pubescens, Pinus sylvestris, and Picea abies at the two sites of Salgesch and Jeizinen

The beginning of gas exchange of Q. pubescens was deduced from measurements of the ratio between actual and potential transpiration (T PET^–1) and corresponded with about the time of completed leaf expansion. P. sylvestris and P. abies were able to be active all seasons. Radial growth was deduced from stem radius measurements.

^a n.m., No measurements.

Table 5. Mean annual radial growth of Quercus pubescens and Pinus sylvestris in comparison to microclimatic and physiological factors during growth periods of the years 1998 to 2004 at Salgesch

Regression analyses were done (grey-coloured cells) for annual radial growth and the respective factors and intra-annual radial growth and the corresponding factors of 10 d periods of the years 2002 to 2004. (+) and (–) indicate a positive or a negative slope of growth on the respective factor. n.a., not applicable; T PET^–1, ratio between actual and potential transpiration.

Table 6. Mean annual radial growth of Q. pubescens, P. sylvestris, and Picea abies in comparison to microclimatic and physiological factors during growth periods of the years 2003 and 2004 at Jeizinen

Regression analyses were done (grey-coloured cells) for intra-anual radial growth and corresponding factors of 10 d periods.