Jeyanny V 1 *, Muhammad Asri L 1 , Darshini R 1 & Mohd Afzanizam M 2
F- Values and Statistical Significance DF Aboveground
Biomass
Carbon content (%) Carbon stocks
D 2 30.777** 2.101ns 0.920ns
TC 2 9.560** 32.218** 0.598ns
DBH * TC 4 2.426ns 1.782ns 0.540ns
DF = Degree of freedom, DBH = Diameter class, TC = Tree components, * = significant at p < 0.05, **
= significant at p < 0.01, ns = not significant at p > 0.05
Table 5 Observed and estimated biomass components, carbon density and carbon content Tree Components
Observed Estimated
AGB AGC AGB AGC
(kg) (kg) (%) (Mg ha-1) (Mg ha-1)
Stem (1) 311.9 118.6 38.04 10.6 4.1
Branch/twigs (2) 264.4 104.7 39.59 8.6 3.4
Leaf (3) 131 56.9 43.42 4.4 1.9
Total 707.3 285.4 40.35* 23.6 9.4
Note: * was an average of the carbon content of (1), (2), and (3)
Table 6 The average amount of above-ground biomass. Above-ground carbon and CO2 sequestered in specific 10 years A. malaccensis plantation
Tree average amount Observed trees (kg) One hectare (Mg)
AGB 707.3 23.6
AGC 285.4 9.4
CO2 Sequestered 1046.4 34.5
DISCUSSION
The stems and branches enclose the largest proportion of aboveground biomass (Komiyama et al.
2008). The plantation has more medium and large diameter classes, contributing more than 50% of AGB. It corresponds with the fact that the larger the stem diameter, the greater the biomass value (Manalu et al. 2016). Similar to previous studies, the result shows that the diameter at breast height is the best predictor (Chave et al. 2014). Several studies proposed some standard conversion factor of biomass to carbon is 50% or half of the biomass was composed biomass (Schroeder 1993). It is also supported by Houghton et al. (1995), which stated the conversion 50% of biomass turned to carbon. Another study found that the species wood density as a model variable considering 47%
carbon contents in woody biomass (Hengeveld et al. 2015). We found that the value of carbon content gradually increased from the lower (stem: 38.04%) to the higher (leaf: 43.42%) in the component observed. Considering this plantation is still young, the stem and crown are in the development stage, the average value of 40.35% of carbon content measured reflects the actual value of carbon absorbed by A. mallacensis at the age of 10 years in this plantation forest. Therefore,
68
the rate of CO2 absorption (34.5 Mg ha-1) in this A. malaccensis plantation also plays a significant role in reducing atmospheric CO2 even at short rotation-aged.
CONCLUSION
This study showed that there is a significant contribution of different diameter classes to the aboveground biomass and carbon stock values. Over the past ten years, with three diameter classes represented in this plantation site, the information on aboveground biomass and carbon stocks obtained in this study can represent Aquilaria's productivity. Through allometric equations developed (Eqn. No.1, 2, 3 & 4), the amount of stem, branch-twigs, leaves, and total aboveground biomass respectively can be predicted using the diameter at breast height (DBH). The rate of carbon sink during the period of the trees being planted until it was ready to be harvested can be estimated with the average carbon content measured at 40.35%. This specific A. malaccensis plantation site has accumulated a significant amount of carbon for the past 10 years and more or less contributed in reducing atmospheric CO2. The determination amount of carbon stocks that were presented in this plantation helps to mitigate global warming by capturing and storing carbon as well as enhancing natural sequestration.
ACKNOWLEDGMENT
This research was supported by Research, Pre-Commercialization & Publication Grants (RPP) Forest Research Institute Malaysia (FRIM) with project number FRIM(S).600-1/11/9/41311005006. The authors would like to thank all Product Development Programme (PPH), Natural Products Division (BHS) research group for supporting this research. Special thanks to the Institute Tropical Forestry and Forest Products (INTROP) University Putra Malaysia (UPM) staff for the field and laboratory assistance and to the Higher Institution Centre of Excellent (HICoE).
REFERENCES
CHAVE J, REJOU-MECHAIN M, BÚRQUEZ A, CHIDUMAYO E, COLGAN MS et al. 2014. Improved allometric models to estimate the aboveground biomass of tropical trees. Global Change Biol. 20, 3177e3190.
HERYATI Y, DEBORA B, ARIFFIN A et al. 2011. Growth performance and biomass accumulation of a Khaya ivorensis plantation in three soil series of ultisols. American Journal of Agricultural and Biological Science 6:33-44. ISSN 1557-4989.
HOUGHTON JT, MEIRA FILHO LG, BRUCE JP, LEE H, CALLANDER BA & HAITES EF. (Eds.). 1995. Climate change 1994: radiative forcing of climate change and an evaluation of the IPCC 1992 IS92 emission scenarios. Cambridge: Cambridge University Press.
69
IQBAL PAS, MOHD ASMADI I, MOHAMMAD FR & NORIZAH K. 2020. Investigating Tree Stand Parameter for Rubber Tree Aboveground Biomass and Carbon Stock Estimation. The Malaysian Forester. 2020, 83 (2): 435 – 452.
HAN MNI, ISLAM MR, RAHMAN A et al. 2020. Allometric relationships of stand level carbon stocks to basal area, tree height and wood density of nine tree species in Bangladesh. Global Ecology and Conservation 22 (2020) e01025. doi: https://doi.org/10.1016/j.gecco.2020. e01025.
KOMIYAMA A, ONG JE & POUNGPARN S. 2008. Allometry, biomass, and productivity of mangrove forests: A review. Aquatic Botany 89:128-137.
LILLIAN SLC. 2008. Agarwood (Aquilaria malaccensis) in Malaysia. NDF Workshop Case Study. Mexico.
MANALU DN, RAHMAWATY & RISWAN. 2016. Pendugaan cadangan karbon aboveground biomass di Kecamatan Lumban Julu Kabupaten Toba Samosir. Peronema Forestry Science Journal Vol 5: No 3.
NOR AZAH MA, SAIDATUL HUSNI S, MAILINA J, SAHRIM L, ABDUL MAJID J & MOHD FARIDZ Z. 2013.
Classification of agarwood (gaharu) by resin content. Journal of Tropical Forest Science 25(2): 213–
219.
PERSOON GA 2008. Growing ‘The Wood of The Gods’: Agarwood production in Southeast Asia. In:
SNELDER DJ, LASCO RD. (eds) Smallholder Tree Growing for Rural Development and Environmental Services. Advances in Agroforestry, Springer, Dordrecht 5: 245-262.
SCHROEDER P. 1993. Agroforestry systems: integrated land use to store and conserve carbon. Climate Research 3: 53-60.
SHIDIQ IPA, MOHD HASMADI IH, RAMLI MF & KAMARUDIN N. 2017. Combination of ALOS PALSAR and Landsat 5 imagery for rubber tree mapping. The Malaysian Forester 80: 55-72.
70
IMPACTS OF CARBON DIOXIDE RISE ON SELECTED MANGROVES SPECIES AT SG. HJ.
DORANI FOREST RESERVE AND MATANG MANGROVE FOREST RESERVE
Azian M*, Marryanna L, Nik Norafida NA, Mohd Ghazali H & Tariq Mubarak H Forest Research Institute Malaysia, 52109 Kepong, Selangor, Malaysia
Mangrove forests, also called mangrove swamps, mangrove thickets or mangals, naturally sequester carbon dioxide during photosynthesis. Several studies have shown that changes in CO2 will affect plant physiological responses, stimulate photosynthesis, cause increased carbon uptake and assimilation. Thus, this study was conducted to measure the net rate of photosynthesis and respiration for selected mangrove species and to determine the effect of carbon dioxide (CO2) concentration on selected mangrove species (Rhizophora apiculata, Rhizophora mucronata, Avicennia alba and Avicennia officinalis) at Sg. Hj. Dorani Forest Reserve (FR) and Matang Mangrove FR.
Particularly, the rate of photosynthesis was seen to increase with the increase in CO2
concentration for the four study species in both Sg. Hj. Dorani FR and Matang Mangrove FR. The rate of photosynthesis is also seen to be low at night for species being studied.
CO2 concentrations have a significant effect on the rate of photosynthesis for these species depending on different times where p<0.05 at Sg. Hj. Dorani FR except for Avicennia officinalis whilst in Matang Mangrove FR, CO2 concentrations only affect the rate of photosynthesis of Rhizopora apiculata and Avicennia officinalis with p<0.05.
Rhizopora apiculata can respond better to changes in CO2 concentration either in the morning or evening or in either the high tide or low tide condition. These findings are based on short-term observations; therefore, it is recommended that similar studies be conducted in the long term and include more variables to understand the mangrove ecosystem and its role in assessing and monitoring the impact of climate change.
Keywords: Elevated CO2 concentration, photosynthesis, climate change, coastal wetlands
INTRODUCTION
Mangrove forests are referred to as one of the various habitats and natural coastal environments other than muddy areas, sandy substrates, rocky beaches, mangrove forests, submerged aquatic plants and coral reefs - providing food, shelter and breeding grounds for terrestrial species (Nagelkerken et al. 2008). Some studies have shown that changes in CO2 will affect the physiological responses of plants, stimulate photosynthesis, and lead to increased carbon uptake and assimilation, to the point of increasing growth-data to support the study is still lacking, especially for forest species.
71
It is important to be able to measure the level of environmental stress in mangrove plants - physiologically, the mangrove species is a stress-resistant species (Ahmad 2006). Thus, this study was carried out to measure the net rate of photosynthesis and respiration for selected mangrove species and to determine the effect of carbon dioxide (CO2) concentration on selected mangrove species (Rhizophora apiculata, Rhizophora mucronata, Avicennia alba and Avicennia officinalis) at Sg.
Hj. Dorani Forest Reserve (FR) and Matang Mangrove FR.
MATERIALS AND METHODS
The study areas are located at Sg. Hj. Dorani Forest Reserve (FR) and Matang Mangrove FR. The mangrove forest of Matang covers an area of 40 711 ha, along a 52 km stretch of the northern coast of Perak. Managed by the Forestry Department of Perak, it is the single largest mangrove forest reserve in Peninsular Malaysia, accounting for 40% of the total mangrove forest in the peninsula. Sg.
Hj. Dorani is located 90 km to the north of Kuala Lumpur, near Sabak Bernam, on the west coast of Peninsular Malaysia. It is nearly 2.6 km long and has a 1:100 foreshore slope. Bernam River and Perak River both carry a huge number of sediments to the Malacca Strait (Cleary & Goh 2000), meeting the coastline some 40 km away from Sg. Hj. Dorani. Littoral currents distribute this fluvial discharge over the shoreline to the Sg. Hj. Dorani beach where destruction of the coastal forest decreases the chance of sediment deposition. For each study site, four species were selected (Rhizophora apiculata, Rhizophora mucronata, Avicennia alba and Avicennia officinalis) with three replicates for each species that make 24 trees being tagged. The CO2 concentration was elevated at 50 ppm, 100 ppm, 200 ppm, 400 ppm, 600 ppm, 800 ppm and 1600 ppm and their photosynthesis rate was measured using LICOR 6400. The reading was taken three times a day, in the morning, evening and night for each replicate.
RESULTS AND DISCUSSION
All four species in both study areas showed a higher rate of photosynthesis with an increase in CO2
concentration in the morning and evening (presence of light), however, the trend was seen to be different at night. The rate of photosynthesis for R. apiculata is higher than R. mucronata for both study areas. The photosynthesis rate of A. officinalis with CO2 enrichment was higher in the evening;
on the other hand, A. alba was higher in the morning and the evening (Figure 1).
72
Figure 1 Photosynthesis rate of selected species at Sg. Hj. Dorani Forest Reserve and Matang Mangrove Forest Reserve
The test results of the relationship between time difference and CO2 concentration on the rate of photosynthesis of each study species in Hj. Dorani FR. The time factor in the morning, evening and night showed a significant difference of P <0.05 for the species of R. apiculata, A. officinalis and A.
alba. This means that time has a significant effect on the rate of photosynthesis of these species.
However, for R. mucronata, time did not affect its photosynthesis rate statistically when tests showed no significant difference i.e., P> 0.05.
The CO2 concentration factor showed a significant difference of P <0.05 for the species of R.
apiculata, R. mucronata, A. officinalis and A. alba. This means that different CO2 concentrations have a significant effect on the rate of photosynthesis of these species.
The interaction between time and CO2 concentration also showed significant differences (P <0.05) for the species of R. apiculata, R. mucronata and A. alba. It means that CO2 concentrations have a significant effect on the rate of photosynthesis of these species depending on different times; but not for A. officinalis where P> 0.05.
73
The test results of the relationship between time and CO2 concentration on the rate of photosynthesis of each study species in Matang Mangrove FR showed that the time factor of the morning, evening and night showed a significant difference of P <0.05 for the four species R.
apiculata, R. mucronata, A. officinalis and A. alba. This means that time has a significant effect on the rate of photosynthesis of these species.
The CO2 concentration factor showed a significant difference of P <0.05 for R. apiculata and A.
officinalis. This means that different CO2 concentrations have a significant effect on the rate of photosynthesis of these species. In contrast, CO2 concentrations did not provide a statistically significant effect (P> 0.05) on the rate of photosynthesis for R. mucronata and A. alba.
The interaction between time and CO2 concentration also showed significant differences (P <0.05) for R. apiculata and A. alba species. This suggests that CO2 concentrations have a significant effect on the rate of photosynthesis of these species depending on different times. But not for R.
mucronata and A. alba where P> 0.05.
As a discussion, the rates of photosynthesis for all study species were low at night. It is because photosynthesis does not occur at night for most plants due to the process of photosynthesis carried out by plants require sunlight. The concentration of carbon dioxide is also influenced by the rate of photosynthesis of the mangrove species studied. It is also evidenced by previous studies looking at interactions between plant photosynthesis with environmental factors (Long 1991; McMurtrie &
Wang 1993; Teskey 1997; Ziska & Bunce 1997a, b; Saxe et al. 2001, Turnbull et al. 2002).
CONCLUSION
Rhizophora apiculata is able to respond to changes in the concentration of CO2 than to R. mucronata especially in the morning or in the afternoon. It is important to know the appropriate rate of stomata opening for the exchange of CO2 (food manufacturing and tree growth). The efficiency of photosynthesis/respiration depends on light/temperature. These data are important to understand physiological processes in mangrove forests which have not been well explored in Malaysia. These findings are based on short-term observations; therefore, it is recommended that similar studies be conducted in the long term and incorporate more modifiers to understand the mangrove ecosystem and its role in assessing and monitoring the impacts of climate change.
ACKNOWLEDGEMENT
We thank the staff of the Climate Change and Forestry Program and Ecohydrology Program for their assistance with chamber measurements, and tree surveys and for conducting field works. We would also like to thank the Technical Committee for Research and Development of the program of planting mangrove trees and other suitable species along the country's coastline in supported us using their fund.
74 REFERENCES
AHMAD MAHDZAN A. 2006. Mangroves and Ecotourism: Ecological or Economical?
mahdzan.com/papers/mangrove/08. asp. Retrieved 10 February 2009.
CLEARY M, GOH KC. 2000. Environment and Development in the Straits of Malacca. Routledge, London, pp. 214.
LONG SP. 1991. Modification of the response of photosynthetic productivity to rising temperature by atmospheric CO2 concentrations: has its importance been understood? Plant, Cell and Environment 14, 729–739.
MCMURTRIE RE & Wang YP. 1993. Mathematical models of the photosynthetic response of tree stands to rising CO2 concentrations and temperatures. Plant, Cell and Environment 16: 1–13.
NAGELKERKEN I, Blaber S, Bouillon S, Green P, Haywood M, Kirton LG, Meynecke J, Pawlik J, Penrose, H, Sasekumar A & Somerfield P. 2008. The habitat function of mangroves for terrestrial and marine fauna: A review. Aquatic Botany. 89. 10.1016/j.aquabot.2007.12.007.
SAXE H, Cannell MGR, Johnsen Ø, Ryan MG, Vourlitis G. 2001. Tree and forest functioning in response to global warming. New Phytol 149:369–400. doi:10.1046/j.1469-8137.2001.00057.
TESKEY RO. 1997. Combined effects of elevated CO2 and air temperature on carbon assimilation of Pinus taeda trees. Plant, Cell and Environment 20: 373–380.
TURNBULL MH, MURTHY R & GRIFFIN KL. 2002. The relative impacts of daytime and night-time warming on photosynthetic capacity in Populus deltoids. Plant, Cell and Environment 25: 1729–1737.
ZISKA LH & Bunce JA. 1997a. Influence of increasing carbon dioxide concentration on the photosynthetic and growth stimulation of selected C-4 crops and weeds. Photosynthesis Research 54: 199–208.
ZISKA LH & Bunce JA. 1997b. The role of temperature in determining the stimulation of CO2 assimilation at elevated carbon dioxide concentration in soybean seedlings. Physiologia Plantarum 100: 126–132.
75
ASSESSMENT OF CLIMATE CHANGE IMPACTS ON TROPICAL FOREST ECOSYSTEM AND FORMATION OF APPROPRIATE ADAPTATION STRATEGIES: TekamFACE SYSTEM
Azian M1, Nik Norafida NA1, Nurul Ain AM1, Muhammad Syafiq R1, Wan Mohd Shukri WA1, Mohd Nizam MS2, Samsudin M3, Mohd. Puat D3, Samsu Anuar N4 & Mohd Zarin R5
1Forest Research Institute Malaysia, 52109, Kepong, Selangor, Malaysia
2Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
3Forestry Department of Peninsular Malaysia, Jalan Sultan Salahuddin, 50660 Kuala Lumpur
4Pahang Forestry Department, 5th floor, Kompleks Tun Razak, Bandar Indera Mahkota, 25990 Kuantan, Pahang
5District Forest Office, Jerantut Batu 1, Jalan Benta, 27000 Jerantut, Pahang
Forestry is the second most important sector in the discussion of global climate change issues. This sector is hotly debated as it is often associated with greenhouse gas emissions through logging activities. Given the importance of the forestry sector to our economy, it is appropriate that we understand more deeply the impact of climate change on the country's forest resources. Assessment of Climate Change Impacts on Tropical Forest Ecosystem was done to study the changes to forest ecosystem and productivity in the production forest with elevated CO2 levels through TEKAM Free-Air Carbon Dioxide Enrichment (TekamFACE) system. TekamFACE system was built to release additional CO2 into the air, elevating atmospheric CO2 from 410- 450 ppm (ambience) to 600 ppm and above (elevated). This is done in the production forest and allows long term study in a natural environment. Appropriate adaptation strategies will then be planned if introduced species are needed to be planted for sustainable forest management. The adaptation steps of the forestry sector toward climate change are to be included in the National Report and for the use of the Malaysian Adaptation Plan in preparing the United Nations Framework Convention on Climate Change (UNFCCC) report. Climate change will affect the forest ecosystem, growth and productivity and hence sustainable forest management principles are necessary.
Keywords: CO2 enrichment, species adaptation, tropical production forest
INTRODUCTION
Climate change has been observed since 1950 with exponential anthropogenic carbon dioxide (CO2) emission for at least the past 50 years (Hofmann 2008). The CO2 concentrations can reach up to 936 ppm (RCP*8.5) by the year 2100 as predicted by Intergovernmental Panel on Climate Change (IPCC) (IPCC, 2013). A study through computer modelling projections by Azian et al. (2018) showed an increase in productivity of tropical rainforests especially in Malaysia by 13% or 12.8 GgC ha-1 with an increase in CO2 and temperature under the Representative Concentration Pathway (RCP) 8.5
76
scenario, and a decrease in forest productivity of 7% or 8 GgC ha-1 with an increase in temperature only in under the RCP 8.5 C90 scenario by 2099.
As a starting point to support the preparation process and construction of the National Adaptation Plan (NAP), the Government of Malaysia has allocated funds in the Eleventh Malaysia Plan to the Forest Research Institute Malaysia (FRIM) to conduct a study entitled “Climate Change Assessment of Ecosystems Forests and the Establishment of Appropriate Adaptation Strategies”. This research was conducted for five years from 2016 to 2020 through a memorandum of agreement (MoA) between FRIM and UKM on 12 April 2016. The objective of the MoA was particularly on the establishment of the TekamFACE system that consists of the control house and a structure of hexagon to release the elevated CO2 gases within a budget of RM525,000.00. This system is designed to enable the study of the response of forest vegetation species to an increase in CO2 gases by creating the facilities with an experimental space that can produce environmental conditions with an increase in the concentration of CO2 gas.
MATERIALS AND METHODS
The construction of the TekamFACE system in the form of a control house and a structure of a hexagon as high as 12 m and a 6 m side has been implemented in the Compartment 84, Tekam Forest Reserve, Jerantut, Pahang. It releases additional CO2 into the air, elevating atmospheric CO2
from 500 ppm to 600 ppm and above (elevated) (Azian et al. 2020). This is done to allow long term study of the assessment of climate change impacts on tropical forest ecosystems in a natural environment.
RESULTS & DISCUSSION
TekamFACE system (Figure 1) was successfully operated in 2018 that needs to be integrated with the control panel house and the data observation computer so that it can generate accurate field data.
Generally, the operation of this TekamFACE system begins with the production of CO2 gas from the gas tank at the control house, followed by the release of the CO2 gas through the flow pipe into the airspace within the FACE hexagon. Then, as shown in Figure2, data is transmitted from the 4 in 1 sensor via LAN/Wifi, stored in the computer using EZ ICMS software, and monitored using an Android phone. 4 in 1 sensor have been installed in the Tekam Forest Reserve plot, Jerantut, Pahang to measure the air of the forest environment. Among the parameters measured are (1) CO2 (ppm), (2) Air humidity (% RH), (3) Light intensity (Lux) and (4) Temperature (°C) with a frequency every 10 min for 24 hours/day. Generally, the normal forest environment shows the average monthly range of CO2 is 495 ppm, temperature at 26.9 ° C, humidity at 84.2% and light intensity at 110 Lux. Starting June 2018, the increase in CO2 gas in the normal environment is ± 125 ppm within the FACE hexagon range. Meanwhile, the operating manual of the TekamFACE system has been published in 2018 and received the award of the best manual published during FRIM Awards Day 2019 (Figure 3). The manual was then upgraded in January 2021 with additional troubleshooting steps to be taken when the system is not functioning well. Furthermore, this system was awarded in The Malaysia Book of