CO2 Temperature and Trees

by Dieter Overdieck

CO2 Temperature and Trees This comprehensive book discusses the ecophysiological features of trees affected by the two most prominent factors of climate change atmospheric CO2 concentration and temperature It starts with the introduction of experimental methods at the leaf branch the whole tree and tree group scales and in the following chapters elaborates on specific topics including photosynthesis of leaves respiration of plant organs water use efficiency the production of and or distribution patterns of carbo

Publisher : Springer Singapore

Author : Dieter Overdieck

ISBN : 9789811018596

Year : 2016

Language: en

File Size : 8.89 MB

Category : Science Math

Ecological Research Monographs

Dieter Overdieck

CO2 ,
Temperature,
and Trees
Experimental Approaches

Ecological Research Monographs

Series editor
Yoh Iwasa

More information about this series at http://www.springer.com/series/8852

Dieter Overdieck

CO2, Temperature, and Trees
Experimental Approaches

Dieter Overdieck
Institute of Ecology, Ecology of Woody Plants
Technical University of Berlin
Berlin, Germany

ISSN 2191-0707
ISSN 2191-0715 (electronic)
Ecological Research Monographs
ISBN 978-981-10-1859-6
ISBN 978-981-10-1860-2 (eBook)
DOI 10.1007/978-981-10-1860-2
Library of Congress Control Number: 2016954422
© Springer Science+Business Media Singapore 2016
This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of
the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations,
recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission
or information storage and retrieval, electronic adaptation, computer software, or by similar or
dissimilar methodology now known or hereafter developed.
The use of general descriptive names, registered names, trademarks, service marks, etc. in this
publication does not imply, even in the absence of a specific statement, that such names are exempt
from the relevant protective laws and regulations and therefore free for general use.
The publisher, the authors and the editors are safe to assume that the advice and information in this
book are believed to be true and accurate at the date of publication. Neither the publisher nor the
authors or the editors give a warranty, express or implied, with respect to the material contained
herein or for any errors or omissions that may have been made.
Cover illustration: Systems for measuring CO2 and temperature effects on groups of juvenile trees
[object: European beech (Fagus sylvatica)]
Printed on acid-free paper
This Springer imprint is published by Springer Nature
The registered company is Springer Science+Business Media Singapore Pte Ltd.

Preface

For more than a century, it has been known that elevated CO2 concentrations in the
air lead to enhanced plant growth. “CO2 fumigation” has even occasionally been
used to increase crop production in greenhouses. Starting around the year 1980, the
scientific community became deeply interested in global changes in ecological
factors, particularly in the profound effects that increasing atmospheric CO2 concentration and increasing temperature are predicted to have on all “players” in
ecosystem functioning. Even then, scientists were calling forcefully for studies on
the direct effects of increasing CO2 and temperature on plants, at scales ranging
from the molecule to the globe. In consequence, the number of relevant publications has grown exponentially, motivated further by deep concerns about potential
impacts on biological processes. As trees store a great deal of carbon from atmospheric CO2 in their biomass, it is vital to know how CO2 enrichment and temperature increases will influence these long-living carbon pools.
In this book, my main objective is to briefly summarize the output of 30 years of
experimental work conducted at the University of Osnabr€uck and at the Technical
University of Berlin, Germany. A series of projects, supported by the European
Union, provided the basis of the teamwork.
The second aim was to place our work—the experimental results, ideas, and
contributions to discussion—into the context of the existing global scientific
research that has been undertaken and published in recent decades. Literature
selection had to be extensive, but cannot be complete, because of the huge number
of relevant, wide-ranging publications including many meta-analyses. Selection
was mainly based on personal cooperation in research projects and acquaintanceships made during scientific meetings. Therefore, many thanks go to a great number
of colleagues who provided valuable intellectual stimulation. Their contributions
are documented in the book.
Thirdly, my goal was to incorporate all of the valuable contributions of those I
worked with directly in this compilation so that their important knowledge is not
lost. In addition, recently evaluated data from a series of experiments with woody
plants that are yet unpublished have been included. This last effort was particularly
v

vi

Preface

important because the research programs on the effects of elevated CO2 concentration and temperature on trees cannot be continued at the Technical University of
Berlin.
Special thanks go to Kelaine Vargas Ravdin (San Francisco, California, USA)
for the intensive and professional language editing and to my daughter Simone
Overdieck for her unwavering support during the whole work.
Berlin, Germany
April 2016

Dieter Overdieck

Contents

1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.1
Atmospheric CO2 Concentration . . . . . . . . . . . . . . . . . . . . . .
1.2
Temperature in the Lower Atmosphere . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.
.
.
.

1
1
6
9

2

Research Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1
Gas-Exchange Systems for Leaves and Stems . . . . . . . . . . . .
2.2
Greenhouses and Cabinets . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3
Branch Bags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4
Open-Top Chambers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5
Whole-Tree Chambers . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.6
Free-Air CO2 Enrichment . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.7
Natural Carbon Dioxide Springs . . . . . . . . . . . . . . . . . . . . . .
2.8
Model Ecosystems (Microcosms, Mesocosms, Biospheres) . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.
.
.
.
.
.
.
.
.
.

11
11
12
14
16
18
18
21
22
29

3

CO2 Net Assimilation of Leaves . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1
[CO2] as a Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2
Light and [CO2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3
Temperature and CO2 Net Assimilation . . . . . . . . . . . . . . . . .
3.4
Nitrogen and CO2 Gas Exchange . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.
.
.
.
.
.

33
33
36
39
41
43

4

Respiration in Plant Compartments . . . . . . . . . . . . . . . . . . . . . . .
4.1
Leaves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2
Stems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3
Roots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.
.
.
.
.

47
47
49
51
53

vii

viii

Contents

5

Water Use Efficiency and Stomatal Conductance . . . . . . . . . . . . . .
5.1
Water Use Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2
Stomatal Conductance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3
Interaction with Ozone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

57
57
57
61
62

6

Nonstructural and Structural Carbohydrates . . . . . . . . . . . . . . . .
6.1
Nonstructural Carbohydrates . . . . . . . . . . . . . . . . . . . . . . . . .
6.2
Structural Carbohydrates . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2.1
Hemicellulose Compounds . . . . . . . . . . . . . . . . . . . .
6.2.2
Cellulose and Lignin . . . . . . . . . . . . . . . . . . . . . . . .
6.2.3
Carbohydrates in Roots . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.
.
.
.
.
.
.

65
65
72
72
72
77
77

7

Secondary Metabolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.1
Volatile Organic Compounds . . . . . . . . . . . . . . . . . . . . . . . .
7.2
Chlorophyll and Other Pigments . . . . . . . . . . . . . . . . . . . . . .
7.3
Other Secondary Metabolites . . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.
.
.
.
.

81
81
84
86
86

8

Macro- and Micronutrients . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.1
Macronutrients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.1.1
Nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.1.2
Phosphorus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.1.3
Potassium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.1.4
Calcium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.1.5
Magnesium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.1.6
Sulfur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.2
Micronutrients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.
.
.
.
.
.
.
.
.
.

89
89
89
101
103
104
106
108
108
112

9

Anatomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.1
Leaf Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2
Stem Tissues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2.1
Bark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2.2
Wood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2.2.1 Wood Density . . . . . . . . . . . . . . . . . . . . . .
9.2.2.2 Annual Tree-Ring Width . . . . . . . . . . . . . .
9.2.2.3 Resin Canal and Wood Ray Density . . . . . .
9.2.2.4 Xylem Vessels . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.
.
.
.
.
.
.
.
.
.

119
119
124
124
125
125
126
129
130
136

10

Growth and Mass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.1 Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.2 Basal Stem Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10.3 Summary (Height and Basal Diameter) . . . . . . . . . . . . . . . . .
10.4 Leaves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.
.
.
.
.

143
143
150
155
155

Contents

ix

10.5 Number of Buds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
10.6 Biomass Partitioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
11

Phenology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11.1 Bud Break . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11.2 Leaf Abscission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11.3 Leaf Longevity Overall . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.
.
.
.
.

175
175
176
179
181

12

Expanding the Outlook to Effects on Ecosystems . . . . . . . . . . . . . .
12.1 Leaf Area Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.2 Production and Net CO2 Gas Exchange in Model Ecosystems . . .
12.3 Evapotranspiration of Small Systems . . . . . . . . . . . . . . . . . . . .
12.4 Rhizosphere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.4.1 Litter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.4.2 Soil Bacteria and Fungi . . . . . . . . . . . . . . . . . . . . . . .
12.4.3 Soil Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.5 Herbivory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

183
184
185
195
196
196
198
203
206
211

13

Modeling Responses to [CO2] and Temperature . . . . . . . . . . . . . .
13.1 Leaf and Canopy Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.2 Whole Stand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

217
217
223
227

.
.
.
.

Subject Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
Organism Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237

Chapter 1

Introduction

Abstract The importance of studying the ecological effects of increasing CO2
concentration [CO2] and temperature on trees is emphasized. Detailed measurements documenting [CO2] increases over the past decades are compared. A novel
contribution to the body of knowledge is the presentation of the particularities of
[CO2] (over 20 years) and temperature (over 60 years) for one city (CO2 source).
Daily and yearly courses are shown, and reasons for oscillations are discussed.
Keywords Atmospheric CO2 concentration increase • Daily course of [CO2] • Air
temperature trend • Urban area • Central Europe

1.1

Atmospheric CO2 Concentration

The global concentration of carbon dioxide ([CO2]) in the Earth’s atmosphere
increased from less than 200 μmol mol1 ca. 21,000 years ago to ~379 μmol mol1
in the year 2005 (IPCC 2007; Inderm€uhle et al. 1999; Petit et al. 1999; Monnin
et al. 2001; Augustin et al. 2004). The preindustrial globally averaged [CO2], based
on measurements of air extracted from Antarctic ice cores and from other ancient
ice shields, was 278  2 μmol mol1 (Etheridge et al. 1996). In the late 1950s, the
first accurate systematic measurements of recent atmospheric [CO2] were started
on top of Mauna Loa, Hawaii, USA, and in Antarctica by Keeling et al. (1976a, b).
Since that time, the number of stations where [CO2] of the lower atmosphere is
measured has increased rapidly worldwide.
The global annually averaged concentration in 2011 was 390.5 μmol CO2 mol1,
reflecting an approximately 40 % increase since preindustrial times (IPCC 2013).
The global increase from 2005 to 2011 amounted to ~11.7 μmol mol1 (IPCC
2013).
Among the local stations measuring [CO2] was one in Osnabr€uck, Germany,
where measurements were taken from 1984 to 1993 on the Westerberg hill (city
population ~160,000, 58 180 N, 8 20 E, 95 m a.s.l., data collected at 4.5 and 10 m
above ground). Monthly averages for this period increased from 350 to 362.9 μmol
CO2 mol1, an average annual increase of ~1.3 μmol mol1 (~3.7 %). A high peak
was reached in 1989 (Forstreuter et al. 1994). During these years, the Osnabr€uck
annual increase was nearly the same as at the Mauna Loa station (Keeling and
© Springer Science+Business Media Singapore 2016
D. Overdieck, CO2, Temperature, and Trees, Ecological Research Monographs,
DOI 10.1007/978-981-10-1860-2_1

1

2

1 Introduction
-1

[µmol CO2 mol ]
450

440
y = 0.1957x + 366.2
R2 = 0.6

430

420

410

400

390

380

370

360

IIII
IIII

350
19921993199419951996199719981999200020012002200320042005200620072008200920102011 2012

Fig. 1.1 Monthly [CO2] means, January 1992–March 2013 in Berlin-Dahlem Germany (52 280 N,
13 180 E, 50 m a.s.l.). Values are calculated from daily means determined from air samples taken
once per minute at 4.5 m above ground; unpublished data (Overdieck 2013)

Whorf 1992), although the [CO2] level was 1.2 % lower at the Mauna Loa station at
both the beginning and the end of the measuring period.
Additional measurements took place in Berlin-Dahlem, Germany, from January
1992 to March 2013 (Fig. 1.1). There the annual mean  SD of [CO2] increased
from 365.0  6.6 in 1992 to 416.3  7.2 μmol CO2 mol1 in 2012 or 14.1 % in
20 years with a mean annual increase of ~2.3 μmol mol1. The global mean annual
increase between 1980 and 2011 was 1.7 μmol CO2 mol1. At the Berlin-Dahlem
station, the level of tropospheric [CO2] was ~4.5 % higher than that of the global
concentration (2005–2011). Global annual averages were ~378.8 and 390.5 μmol
CO2 mol1 in 2005 and 2011, respectively (IPCC 2013); for Berlin-Dahlem they
were ~403.8 (2005) and 416.3 μmol CO2 mol1 (2012). The percentage increase
during this time was approximately the same globally and locally (~3.1 %). The
concentration in Berlin-Dahlem reached relatively high values between 1999 and
2001 (Fig. 1.1), whereas global peak averages occurred in 1992 and 1998 (IPCC

1.1 Atmospheric CO2 Concentration

3

2013). Reasons for the local peaks and the difference in timing between local and
global peaks are unknown.
Multiple lines of observational evidence indicate that, during the past few
decades, most of the increasing atmospheric burden of CO2 has been from fossil
fuel combustion (Tans 2009). Another major contribution comes from land use
changes globally and regionally (IPCC 2013). The discrepancy between the global
averages and the averages for the Osnabr€uck and Berlin-Dahlem stations can thus
best be understood in terms of the greater anthropogenic influences through emission sources in the immediate vicinity of the German stations, which were situated
in urban areas.
[CO2] varies over the course of the year. At the two German stations, the
variance was greater than what was seen at the global scale. This suggests that
most of the variability in the growth rate of [CO2] is driven by small changes in the
balance between photosynthesis and respiration on land (IPCC 2013).
Globally and locally a summer decrease in [CO2] is always evident. In urban
areas lower levels of [CO2] may be caused not only by photosynthesis clearly
exceeding respiration in the biosphere in the middle of the vegetative period, but
also by lower fossil fuel burning in households and less individual traffic (holidays)
than in winter, at least in towns of the northern latitudes. An example of this
phenomenon is shown for the year 2009 in Berlin-Dahlem (Fig. 1.2). In January
450
440

y = 1.03x 2 - 14.0x + 436.1
R2 = 0.91

(µmol CO2 mol-1)

430
420

SD

410
400
390
380
370
360

Dec

Nov

Oct

Sep

Aug

July

June

May

Apr

Mar

Febr

Jan

350

2009
Fig. 1.2 Annual variance in [CO2] for 2009, measured at 4.5 m above ground in Berlin-Dahlem,
Germany (52 280 N, 13 180 E, 50 m a.s.l.); monthly averages calculated from hourly means;
SD: standard deviation; unpublished data (Overdieck 2013)

4

1 Introduction

470

SD

(µmol CO2 mol-1)

450

430

410

390

January :
July
:
370

2012

23:00

22:00

20:00

21:00

19:00

18:00

16:00

17:00

14:00

15:00

13:00

11:00

12:00

9:00

10:00

8:00

7:00

6:00

4:00

5:00

3:00

2:00

0:00

1:00

350

Fig. 1.3 Mean daily course of [CO2] in January (~) and July (o) 2012, measured at 4.5 m above
ground in Berlin-Dahlem, Germany (52 280 N, 13 180 E, 50 m a.s.l.). Values are calculated from
half-hourly averages of measurements taken each minute; SD: standard deviation; unpublished
data (Overdieck 2013)

the monthly average of atmospheric [CO2] was ~423.1, in the middle of summer
(June–August) it fell to ~389.3, and in December returned to ~416.4 μmol mol1. In
this particular case, this summer effect meant a reduction of [CO2] by ~8 % in
relation to the winter level.
The influence of the biosphere becomes especially obvious when comparing
mean daily values of [CO2] in winter and in summer (Fig. 1.3). In July, the mean
daily course shows that photosynthetic uptake of CO2 not only outweighed CO2
losses during the bright hours of the day but also clearly exceeded photorespiration
and the lower levels of anthropogenic CO2 releases. At night, dark respiration
(RDsystem) of the biosphere (and released anthropogenic CO2) drove [CO2] to
relatively high values. It is also striking that the “noise” (variability, SD in
Fig. 1.3) of values was lower during the bright hours of the days in July compared
with the values measured at night. In contrast, in January the mean daily course of
[CO2] was comparably stable during day and night and revealed little or no
influence of the biosphere.
In January the small peak of [CO2] around 9:00 am and the slight increase in late
afternoon and evening (Fig. 1.3) can be partly explained in terms of increased fuel
burning from traffic (rush hour effect) and heating in the evening. The increase in
[CO2] from its low point late at night (3:30 am) to 9:00 am amounted to ~5.3 μmol

1.1 Atmospheric CO2 Concentration

5

(µmol CO2 mol -1)
470
450
430
410
390

month

370

20:00

Mar-12
22:00

16:00

18:00

May-12
14:00

12:00

Jul-12
10:00

08:00

Sep-12
06:00

04:00

Nov-12
02:00

00:00

350

Jan-12

(h)

Fig. 1.4 Mean daily courses of [CO2] in each month of 2012, measured at 4.5 m above ground in
Berlin-Dahlem, Germany (52 280 N, 13 180 E; 50 m a.s.l.). Values are hourly means of measurements taken once per minute; unpublished data (Overdieck 2013)

CO2 mol1. Variability in winter was also greater at night than during the bright
hours of the day, but not to the same extent as in July.
Figure 1.4 presents the mean daily courses of [CO2] for each month for the year
2012 and makes visible a small shift of the summer decrease to later hours of the
day as well as a slight delay in the increase following the summer reduction in the
subsequent autumn.
There is substantial consensus in the scientific literature (IPCC 2013) that CO2
emissions will continue to increase during the twenty-first century and even
beyond. Models simulating atmospheric [CO2] predict different rates of increase
through 2100 because of uncertainties about the amount of CO2 emissions in the
future. The predictions range from 794 to 1149 μmol mol1 by the year 2100 (IPCC
2013). One multi-model average forecasts 985  97 μmol CO2 mol1 by 2100
(Collins et al. in IPCC 2013). This would be more than a doubling of [CO2] from
the level in 2013. Increases in [CO2] are expected to occur across all ecosystems
making this change unique among global change factors (Ward and Strain 1999),
and thus biological processes at all levels may be affected, from cells and molecules
to plant organs to trees to forests.
It has long been known that woody plants react to brief elevations of [CO2] by
increasing their uptake of CO2 (Godlewski 1873, Nerium oleander). In addition, it
is known that trees store a great deal of the global terrestrial carbon in their biomass
C (K€
orner 2006), and this forest biomass pool is relatively long-lived. Forests cover
~30 % of the terrestrial area, contribute 50 % of the net primary productivity (NPP),

© 2018-2019 uberlabel.com. All rights reserved