Needle/leaf physiology within a tree crow n and its ffects at whole tree level Prot Mae nD arch Institute WSL 可南信阳杨树 南，马尾书 广东校树
1 Needle/leaf physiology within a tree crown and its effects at whole tree level Tree Physioecology Swiss Federal Research Institute WSL Insect defoliation, Illinois Quercus sp. Top-down defoliation pattern typical of Douglas-fir tussock moth 河南信阳，杨树 广东， 桉树 湖南, 马尾松 马尾松毛虫俗称“狗毛虫”。以幼虫取食松 树针叶为害， 是我国南方各省危害森林最为 严重的害虫，每年受灾面积往往以千万亩计， 造成巨大的经济损失。松树被害后，轻者造 成材积生长率下降，松脂减产，种子产量降 低；重者致使松树生长极度衰弱，容易招引 松墨天牛、松纵坑切梢小蠹、松白星象等蛀 干害虫的入侵，造成松树大面积死亡。此外， 幼虫具毒毛，容易引起人的皮炎 和关节肿痛
Trends in fore schwach geschadig s126% Main causes of defoliaton Biological causes:insects/disease/livestock Mechanical damage 4.Air pollution:emissions and effluents into the ai soil and water degrades the environment and pton-lg TREE GROWTH ZONES R8a 2
2 Trends in forest defoliation in Europe for the period 1992 to 2003 efoliation of crown cover Proportion of trees with >25% d www.fao.org/docrep/008/ae428e/ae428e02.htm Forests in Germany, 2007. www.wald.de Blattverlust >26% Blattverlust 11-25% -10% -30% -55% -75% 0% 30% 60% 85% Transparency Müller & Stierlin, 1990; Dobbertin, M et al. 2005 -0% -30% -60% -85% 1. Biological causes: insects/disease/livestock 2. Climatic conditions: drought, frost…… 3. Mechanical damage 4. Air pollution: emissions and effluents into the air, soil and water degrades the environment and causes defoliation
Tree's crown-the most important part of a tree Tree leaves can be called the"food factories" even theo lants" by which the tree is able to use light ("photo considered as stored energy and are used to ALENCIA DHANCE TREES OF DIPFERENT ACE 鲨雷蕾出 131 70510 離 20.1 (61) For 30-yrs-old Pinus cembra trees at the alpine treeline: u2C7 3
3 Leaves are a plant‘s food factory. They are the main site of photosynthesis, hotosynthesis, where sugars are made from H2O and CO2, using sunlight energy. Royal Botanic Gardens KEW Tree leaves can be called the “food factories” or perhaps even the “power plants” for trees. It’s in the leaves that most photosynthesis takes place. Photosynthesis is the process by which the tree is able to use light (“photo”) Tree‘s crown – the most important part of a tree by which the tree is able to use light ( photo ) energy to make (“synthesis”) food in the form of carbohydrates. Carbohydrates can be considered as stored energy and are used to provide the energy for growth and the synthesis of other compounds and plant processes. 100-140 yrs old Abies alba trees Needles % Stem % Branches % Stump % Roots % Total % Upper canopy layer trees 5.5 65.1 7.5 8.8 13.1 100 Mid-C-layer trees 5.8 70.5 10.0 8.2 5.5 100 Liu Chunjiang, 2009. PhD thesis, Univ. Helsinki For 30-yrs-old Pinus cembra trees at the alpine treeline: Needles 21%, Branches 19%, Stem wood 47%, Roots 13% Li Mai-He, 1999, PhD thesis, Univ. BOKU, Vienna Bernoulli M, Körner Ch, 1999. Phyton 39, 7-12 Supressed trees 4.6 62.4 5.4 7.5 20.1 100 Levels of light-rPPFD (photosynthetic photon flux density) and ambient CO2 levels within the forest canopy profile Koike T. et al. 2004. in Global Environmental Change in the Ocean and on Land (Eds., M. Shiyomi et al.), pp. 453–472 Han QM et a. 2003. Tree Physiology 23, 851-857 Upper crown Mid-C Lower-C Upper crown Middle C Bottom C Horizontal variations along the firstorder branches in the upper, middle, and lower crown of Pinus densiflora during July 2001. Filled symbols represent the outer-foliated terminals of each branch. Han QM et a. 2003. Tree Physiology 23, 851-857
ensity d (548 umol mol-1)atmospheric [CO2]cond 世出把 E Takeuchi Y.et al 2001.Plat,Coll Emer.24.1257-1268 Pan.C17-10 e rate of 出 片 20 Han OM ct a. 03.Tree 23.851-857 tive c latio ed at ligh eturated conditio g
4 Mean (± SE) daily integrated photosynthetic photon flux density (PPFD, mol m−2 d−1) at the top of, and within, a Populus tremuloides crown under current ambient (343 µmol mol−1) and elevated (548 µmol mol−1) atmospheric [CO2] conditions. Takeuchi Y. et al. 2001. Plant, Cell & Envir. 24, 1257-1268 leaf N concentrations and specific leaf area (SLA) in a Populus tremuloides canopy under open-air CO2 enrichment during the 1999 growing season. Takeuchi Y. et al. 2001. Plant, Cell & Envir. 24, 1257-1268 Upper-canopy measurements were from unshaded leaves on the main terminals. Mid- and lower-canopy positions were fixed at 120 and 40 cm above the ground, respectively. Variations in (a) the rate of light-saturated photosynthesis (Amax), (b) the maximum rate of carboxylation (Vcmax) and (c) the maximum rate of electron transport (Jmax) along first-order branches Upper Middle Bottom in the upper, middle, and lower crown of Pinus densiflora in July 2001. Han QM et a. 2003. Tree Physiology 23, 851-857 343 ppm 548 ppm Takeuchi Y. et al. 2001. Plant, Cell & Envir. 24, 1257-1268 Photosynthesis light response curves Populus tremuloides canopies July Aug. Sept Positive correlation between leaf nitrogen content and Pmax (measured at light and CO2 saturated condition Koike T. et al. 2004. in Global Environmental Change in the Ocean and on Land (Eds., M. Shiyomi et al.), pp. 453–472 Sunny crown and seedlings at gap Shady crown and seedlings at the forest floor Koike T. et al. 2004. in Global Environmental Change in the Ocean and on Land (Eds., M. Shiyomi et al.), pp. 453–472 Relation between leaf nitrogen content (N) and Psat (light-saturated photosynthetic rate) in canopy trees and seedlings Han QM et a. 2003. Tree Physiology 23, 851-857
x(c). The carbohydrates are manufactured by plants during the process of var.elliotti trees in north-central Florida photosynthesis 42 The primary product of photosynthesis is Glucose which is the source of carbohydrates like cellulose.starch etc y RC et 2004.Trmm 24.1209-1220 兰 】 Main soluble sugars Starch isa long,straight chain of glucose units.Starch is the principal polysaccharide Total non-structural carbohydrates (TNC) used by plants to store glucose for later use TNCa tree Carbon as energy. Glucose←→ Starch Non-structural carbobydrates (NSC)= are broken down during the process of Glucose+Fructose+Sucrose+Starch CH2Oa+60:6CO26HO+energy 5
5 Upper- and lower-crown light-saturated net photosynthesis of current-year foliage (Amax(cf)), foliar nitrogen concentration ([N]) and specific leaf area (SLA) of Pinus taeda L. and Pinus elliottii var. elliottii trees in north-central Florida McGarvey RC et al. 2004. Tree Physiology 24, 1209-1220 6CO2 + 6H2O + energy (from sunlight) → C6H12O6 + 6O2 The carbohydrates are manufactured by plants during the process of photosynthesis The primary product of photosynthesis is Glucose which is the source of carbohydrates like cellulose, starch etc. Main soluble sugars Glucose Fructose Sucrose (n is the number of repeating glucose units and ranges in the 1,000's) Starch Starch is a long, straight chain of glucose units. Starch is the principal polysaccharide used by plants to store glucose for later use as energy. Glucose St h arc C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy Carbohydrates are broken down during the process of metabolism to release energy Total non-structural carbohydrates (TNC) Represent a tree’s capital for growth: TNC = Carbon gain (photosynthesis) – Carbon loss (respiration) = total soluble sugars + starch Li MH et al. 2002. Trees 16, 331-337 Non-structural carbohydrates (NSC) = Glucose + Fructose + Sucrose + Starch
Experiment 1 Needle age-dependent LMA Experiment 1 Needle ongevity and age-dependentneede blomass 生deb .1.)and the lowlands (570 m)in Switz 214士2234士152 11k士6170士14523士m LI MH ot al 2006.Troos 20.8t in order to periment2 ents e exposure within crown 。Experimen 13814.3143 Stom xylem+ 6
6 Needle age Current year 1 year 2 years 3 years 4 years >4 years Total† Needle biomass (kg; mean values ± SD) per age class and total needle biomass (kg) in old and young Pinus cembra trees growing in the highlands (2100 – 2300 m a.s.l.) and the lowlands (570 m) in Switzerland* Needle longevity longevity and age-dependent dependent needle biomass biomass Old lowland trees 9.298±1.14 5.555±1.25 + + + 14.853 Young lowland trees 2.016±0.42 1.292±0.47 0.311±0.06 + + 3.619 Old highland trees 18.745±2.32 16.213±2.1 12.227±1.2 5.656±1.01 1.023±0.04 + 53.864 Young highland trees 2.304±0.37 1.887±0.24 1.295±0.35 0.400±0.04 0.084±0.01 + 5.970 * “+” in the table means that few needles still remained † Total needle biomass (kg) of a tree crown Li MH et al. 2006. Trees 20, 611-618 Highland Lowland Young trees Old trees Young trees Old trees Current year needles 214.59±2.61 223.41±15.2 205.50±13.6 212.88±15.4 Leaf mass per unit area (LMA, g m-2; mean values ± SD) of old and young Pinus cembra trees growing in the highlands (2100 – 2300 m a.s.l.) and the lowlands (570 m) in Switzerland Needle age-dependent dependent LMA 1-year-old needles 218.12±6.70 227.90±14.5 213.68±10.5 220.73±18.7 2-year-old needles 221.41±26.26 222.53±16.6 No needles No needles 3-year-old needles 218.90±5.17 225.32±10.1 No needles No needles 4-year-old needles 215.98±18.61 223.52±7.40 No needles No needles Li MH et al. 2006. Trees 20, 611-618 Experiments 2 & 3 are to understand the needle age-related physiology within a crown, in order to develop an accuracy sampling strategy. Hypotheses: 1) concentrations of N, NSC and its components, and δ13C are needle-age dependent, and higher in current dl th i t year needles than in one-year old dl nee es, since the former is physiologically more active than the latter; 2) these concentrations in needles at the south crown side or top crown level are higher than those at the north side or lower crown level, respectively, due to the differences in sunlight exposure within a crown. May July September Sugars Starch NSC Sugars Starch NSC Sugars Starch NSC Current-yr. needles no needle no needle no needle 3.8±0.3a 7.2±0.2a 11.0±0.5a 9.1±0.4a 5.7±0.3a 14.8±0.4 Sugar, starch and NSC concentrations (% d. m., mean value ± SE) of needles of different age-classes needles needle 1-year-old needles 7.3±0.2a 16.4±0.5ab 23.7±0.3a 5.9±0.3b 17.5±0.5b 23.4±0.4b 8.7±0.5a 6.7±0.3ab 15.4±0.3 2-year-old needles 6.7±0.3ab 16.3±0.5ab 23.0±0.4a 5.5±0.2bd 16.5±0.3b 22.0±0.5c 7.3±0.4b 6.5±0.4ab 13.8±0.3 3-year-old needles 6.7±0.4ab 16.5±0.3a 23.2±0.4a 5.0±0.2cd 16.3±0.4b 21.3±0.4c 7.0±0.2b 7.6±0.6b 14.6±0.7 4-year-old needles 5.8±0.3b 15.5±0.4ab 21.3±0.5b 4.7±0.2c 16.2±0.4b 20.9±0.4c 6.3±0.3b 8.3±0.4b 14.6±0.6 5-year-old needles 6.0±0.3b 14.6±0.3b 20.6±0.2b 4.8±0.2c 16.5±0.3b 21.3±0.4c 6.8±0.3b 7.4±0.3ab 14.2±0.3 Li MH et al. 2001. Phyton 41, 203-213 0.0 5.0 10.0 15.0 20.0 25.0 30.0 May July Sept May July Sept May July Sept TNC (% d.m.) N-slope S-slope 2-yr.-old needles Buds Stem wood * 5.0 10.0 15.0 20.0 25.0 TNC (% d.m.) S-side N-side North-facing slope vs. South-facing slope North crown side vs. 0.0 S th id 5.0 May July Sept May July Sept May July Sept T Current yr. needles 2 yr. old needles Buds 0.0 5.0 10.0 15.0 20.0 25.0 30.0 May July Sept May July Sept May July Sept TNC (% d.m.) Lower section Mid-section Upper section 2 yr. old needles Buds Stem xylem South crown side Vertical crown levels: Lower – Middle - Upper Li MH et al. 2001. Phyton 41, 203-213 TNC within a crown Pinus cembra Li MH et al. 2001. Phyton 41, 203-213
Experiment 3 )C-N Yan CE LI MH.PLOS ONE (ur Experiment4 Yamc年.godt山H.in prepartion 7
7 N Sugars Starch NSC δ13C C-N ratio SLA Needle age Current-yr 1.22±0.05a 9.26±0.35b 2.21±0.12b 11.46±0.33b -28.99±0.28 9.54±0.46b 81.39±1.17a 1-yr-old 1 00±0 27b 10 68±0 59a 2 60±0 10a 13 29±0 60a -29 18±0 23 13 32±0 60a 60 42±9 53b Mean values (±SE, n=9 trees) of NSC, soluble sugars, starch, and nitrogen contents (% d.m.), C-N ratio (NSC to N), δ13C(‰), and SLA (cm2/g) in needles within Pinus koraiensis crown. 1-yr-old 1.00±0.27b 10.68±0.59a 2.60±0.10a 13.29±0.60a -29.18±0.23 13.32±0.60a 60.42±9.53b Azimuthal direction South 1.15±0.06 10.03±2.11 2.52±0.09 12.56±0.62 -28.83±0.19 11.23±0.83 70.06±5.69 North 1.07±0.04 9.91±0.43 2.28±0.14 12.19±0.48 -29.34±0.29 11.62±0.73 71.75±5.27 Vertical crown position Top 1.03±0.05 9.31±0.67 2.67±0.12a 11.99±0.62 -28.63±0.20a 11.82±0.90 67.24±8.37 Middle 1.11±0.04 10.63±0.59 2.39±0.12ab 13.01±0.66 -28.79±0.15b 12.00±1.00 69.71±7.89 Bottom 1.19±0.07 9.97±0.63 2.15±0.17b 12.13±0.73 -29.84±0.35b 10.46±0.93 75.77±2.46 Yan CF, Li MH. PLoS ONE (submitted) Nitrogen Soluble Sugar Starch NSC Δ 13C C/N SLA Nitrogen 1 -0.262 -0.333 -0.326 0.170 -0.765** 0.741** Correlation coefficients between NSC, soluble sugars, starch, and nitrogen contents, C-N ratio, δ13C, and SLA in needles within Pinus koraiensis crown. *P<0.05, ** P<0.01. Yan CF, Li MH. PLoS ONE (submitted) g Soluble Sugar 1 0.093 0.973** -0.170 0.771** -0.381 Starch 1 0.318 0.533** 0.424* -0.625* NSC 1 -0.039 0.832** -0.488 Δ13C 1 -0.084 -0.223 C/N 1 -0.763** SLA 1 Understanding past needle/leaf physiology using tree-rings Abies holophylla Picea koraiensis Yan CF, Sigwolf R, Li MH. (in preparation)
Source-sink relationship 兰兰 rve pools should be associated with Source-sink relationship Source-sink relationship A
8 With in situ defoliation, pruning and debudding of treeline trees we intend to test the following hypothesis: (1) A complete removal of previous needle generations (all sources) before spring growth will lead to a massive and seasonally sustained depletion of mobile carbon compounds in all tissue. (2) Pruning of 2/3 of all needled branches (sources and sinks removed) g will have minor negative effects on the reserve pool. (3) Removal of all buds (the major sinks at the beginning of the growing season) will induce an overabundance of carbohydrates when compared to controls. (4) A depletion of reserve pools should be associated with diminished growth. Buds Current-yr. needles 2-year-old needles Stem wood Root wood May Sept July Sept May July Sept May July Sept May July Sept Defoliation experiment Sugar (control) 4.8±0.3 6.8±0.3a 3.6±0.3a 8.8±0.5 6.2±0.8 No data No data No data No data 0.4±0.3 1.3±0.4 0.9±0.1 1.3±0.4a Sugar (treated) 4.4±0.6 4.5±0.3b 1.7±0.3b 6.9±0.7 6.3±0.4 Removed Removed No data No data 0.3±0.3 1.2±0.2 0.8±0.2 0.3±0.3b Starch (control) 4.5±0.2 7.0±0.6 7.5±0.5a 6.6±0.5 14.2±0.9 No data No data No data No data 1.3±0.4 2.6±0.5 3.1±0.5 4.1±0.5a Starch (treated) 4.9±0.4 7.8±0.7 4.9±0.3b 6.6±0.6 15.3±0.7 Removed Removed No data No data 0.9±0.1 2.8±0.5 2.8±0.4 1.2±0.5b Debudding experiment Sugar (control) 1.5±0.6 6.6±0.5a No data No data 4.6±0.6 6.2±0.4 7.3±0.7 0.3±0.2 0.1±0.2 0.1±0.3 1.3±0.4 1.8±0.5 1.3±0.5 S ( d) 1 5 0 7 4 5 0 7b R d R d 5 1 0 5 6 4 0 3 7 3 0 4 0 2 0 2 0 2 0 3 0 3 0 3 1 0 0 3 2 3 0 3 1 3 0 4 Source-sink relationship Sugar (treated) 1.5±0.7 4.5±0.7b Removed Removed 5.1±0.5 6.4±0.3 7.3±0.4 0.2±0.2 0.2±0.3 0.3±0.3 1.0±0.3 2.3±0.3 1.3±0.4 Starch (control) 5.3±0.3 7.1±0.6 No data No data 15.0±0.8 15.6±0.7 4.9±0.7 1.4±0.3 1.5±0.5 1.1±0.3 4.5±1.0 3.5±0.5a 4.2±0.8 Starch (treated) 4.1±0.4 6.5±0.8 Removed Removed 15.4±0.9 17.0±0.9 5.1±0.6 1.3±0.3 1.4±0.4 1.9±0.7 4.4±0.6 6.4±0.6b 6.1±0.6 Pruning experiment Sugar (control) 3.7±0.6 5.8±0.6 5.1±0.2 9.3±0.4 6.3±0.4 6.2±0.4 8.8±0.4 0.2±0.3 0.8±0.6 0.2±0.3 0.5±0.5 1.7±0.8 1.1±0.3 Sugar (treated) 3.6±0.5 5.7±0.6 4.6±0.6 8.5±0.7 5.7±0.6 6.5±0.3 7.8±0.5 0.4±0.4 0.4±0.3 0.1±0.2 0.6±0.4 1.5±0.6 1.3±0.2 Starch (control) 4.7±0.6 5.9±0.5 9.4±0.6 7.4±0.7 15.0±0.7 19.9±0.6 6.9±0.3 2.4±0.7 1.7±0.4a 0.8±0.2 3.3±1.0 7.0±0.4 5.1±0.7a Starch (treated) 4.9±0.4 5.5±0.4 9.6±1.0 5.5±0.4 15.3±1.1 16.9±1.0 6.3±0.7 2.4±0.7 2.5±0.2b 0.7±0.2 2.7±0.8 5.4±0.9 1.5±0.3b Li MH et al. 2002. Trees 16, 331-337 15 0 20.0 25.0 30.0 ration (% d.m.) Control Defoliation Pruning Current year needles Debudding 2-yr. old needles Source-sink relationship 0.0 5.0 10.0 15.0 May July Sept. NSC concentr Control Treated Root wood * * May July Sept. needles * May July Sept. Branch wood * Li MH et al. 2002. Trees 16, 331-337 2-yr. needles 1-yr. needles Current-yr. needles Buds Defoliation Debudding * Pruning Source-sink relationship Li MH et al. 2002. Trees 16, 331-337 0.0 5.0 10.0 15.0 20.0 Root wood Stem wood Branch bark Branch wood ** * *** 0.0 5.0 10.0 15.0 20.0 0.0 5.0 10.0 15.0 20.0 Control Treated * Non-structural carbohydrates concentration (% d.m.)
NSC pools Many studies ed to a significar n the and carbon assimilation .How many leaves/needles does a tree(the Experiment6 erms c Light gradient Hypotheses..... 化anaw se 30%of the full light in sed by a 9
9 Control trees 20 30 40 50 60 70 80 NSC fraction (%) May July September Treated trees (September) Defoliated Pruned Debudded NSC pools 0 10 Needles Branches Wood Roots Needles Branches Wood Roots Li MH et al. 2002. Trees 16, 331-337 Biomass fractions used (according to Li Mai-He, 1999, PhD thesis, Univ. BOKU, Vienna, & Bernoulli M, Körner Ch, 1999. Phyton 39, 7-12): Needles 21%, Branches 19%, Stem wood 47%, Roots 13% Many studies demonstrated that severe defoliation led to a significant reduction in the tree health, growth and productivity and productivity, and carbon assimilation Ericsson A. et al. 1980. J Appl Ecol 17, 747-769 Honkanen T. et al. 1994. Funct Ecol 8, 631-639 Li MH et al. 2001. Schweiz Z Forstwes 152, 389-393 Li MH et al. 2002. Trees 16, 331-337 • How many leaves/needles does a tree (the threshold of transparency) need to remain its "normal" life? • How trees respond to an age-dependent defoliation in terms of C- & N-physiology? Apr 2002 Apr 2002 7 years 4 years 3 years 2 years 1 year -0% -9% -27% -46% -71% Light gradient 30% of the full light intensity 70% of the full light intensity Hypotheses……. • (1) light defoliations of the oldest needles have no effects, whereas a severe defoliation decreases the availability of carbohydrates and, therefore, causes a significant decrease in growth Li MH et al. (in preparation) • (2) the effects caused by a severe defoliation will be detectable for several years • (3) the capability for a carbon compensation of defoliated trees depends on light conditions, being easier in trees growing in full-light conditions rather than in shade
ry of resuits of to-factor rep s for tre s)in cne-year old ht and tr ured for 5 tim a tree and tree-ring increment (measured for 3 years following the defoliation 2 ant for tree-rina)and no intera HTee Tree-ring growth following the defoliation Annual height growth following the defollation UiMHet a (in Gas exchange rate (luly 2003) Nitrogen in source of needles after the defoliation (1)At the shade site defolia ion led to a decrease in Ama At both sites,no defoliation effects on needle N contents for 2 years following defoliation MH et al.(ir LiMH et (in
10 Nitrogen Sugars Starch NSC C-N ratio Height Tree-ring df1 F P F P F P F P F P df2 F P F P Between subjects Light (L) 1 21.003 0.05 p>0.05 p>0.05 p>0.05 30% sunlight 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 Needle N contents (%) 0% -9% -27% -46% -71% p>0.05 p>0.05 p>0.05 p>0.05 70% sunlight Defoliation Li MH et al. (in preparation) At both sites, no defoliation effects on needle N contents for 2 years following defoliation 0 0.2 Apr 02 July 02 Oct 02 Oct 03 Defoliation