A Review on Lightning and its effects on Trees

 

Shelly Rajput

Department of Applied Sciences, Delhi Global Institute of Technology, Haryana, India.

*Corresponding Author E-mail: shelly.rajput@rediffmail.com

 

ABSTRACT:

Lightning in mother’s nature show, which cannot be controlled. Lightning contacts the earth about more than 8 million times a day. Due to so many strikes, the probability of damage to the plants and trees is very high. The total available energy for an average lightning stroke is of the order of 108 Joule. Of the total available energy about 85-90% is dissipated in resistive part of the air column, which appears as heat energy to raise the temperature of column so high, that shock waves are produced due to expansion of the column and strong thunder is produced utilizing almost whole of this heat energy. These heat and shock waves generated during lightning process can damage or even kill the trees instantaneously. Lightning may cause wilting, yellowing, premature fruit drop and other severe injuries to trees. Also, the probability of a tree being struck by lightning depends on the tree size and morphology. This paper seeks to present a review on lightning phenomena, its effects on trees and also provides a brief information how difference among trees can influence lightning effect.

 

KEYWORDS: Lightning, Energy, Heat and Shock waves.

 

 

INTRODUCTION:

History of Lightning:

In 8th century, Benjamin Franklin was first who studied the lightning in a scientific way. With his experiment he proved that the lightning is an electrical phenomenon and that clouds are electrically charged. Franklin flew his famous kite during thunder storm in 1752. By this experiment, he concluded that most of the clouds have negative charges in lower region and positive charges in the upper region. Present phase of lightning research starts from Wilson (1916,1920), he first used electric field measurements to estimate the charge structure in the thunderstorm and the charges involved in the lightning discharge. Today lightning is considered to be a transient high current electrical discharge having path lengths in kilometers.

 

“Necessity is the mother of all invention”, lightning damage to the aircrafts, spacecrafts, trees and other sensitive ground-based installation motivated the scientists to concentrate and study more extensively.

 

Lightning:

Lightning is a giant spark of electricity in the atmosphere, which results from the buildup and discharge of electrical energy between positive and negative charges. Positive charges typically accumulate at the top and negative charges at the bottom of the storm cloud. The rising and descending of air, the movement of water and ice particles within the thunderstorm clouds, separates positive and negative electrical charges within the cloud. Due to separation between positive and negative charges within the cloud an electric field is generated, which allows the spark to jump across the air gap. Lightning may occur within a cloud or between a cloud and the earth. A cloud discharge is a lightning that does not connect to the earth and do not normally strike ground objects. Cloud-to-ground discharge is a lightning that move downwards from cloud towards ground. About 90% of them are initiated by negatively charged leader and they lower negative charge to the earth. In such strikes, generally the base of cloud carries negative charge, while the earth carries positive charge.

 

A cloud -to-ground discharge is the most common earth flash that starts in cloud and brings tens of coulomb of negative cloud charge to the earth. The total discharge called ‘FLASH’ has time duration of about half a second. It comprises of various discharge components, including three or four high current pulse called strokes.

 

Malan (1952, 1955) gave the photographic evidence for the discharge occurring in the cloud and preceding the stepped leader. This discharge within the cloud prior to stepped leader is called “Preliminary Breakdown.” After the preliminary breakdown, the first main cloud-to-ground discharge begins and the negative charge moves towards the ground in the steps. This first stroke is called stepped leader. Pathak and Rajput (2006) calculated the magnitude of electromagnetic radiation in HF-VHF range during stepped leader. For this electric field radiated by corona streamer is integrated theoretically throughout the steeped leader channel.

 

The electric field produced by the charge on the leader enhances when some conducting object like tree, transmission line tower or spacecraft come in its paths. This field enhancement may cause upward electric discharge. When one of the upward moving discharges from the ground contacts the downward moving leader, some tens of meters above the ground, the leader tip is connected to the ground potential. The leader channel is then discharged when a ground potential wave, the return stroke, propagates up the previously ionized leader path. The return stroke effectively lowers to ground, the charge originally deposited on the stepped leader as well as other charges that may be available to the top of the channel. It produces an electric field change. Pathak and Rajput (2021) computed the magnitude of electromagnetic radiation in LF-VHF range by integrating the electric field radiated by corona streamer throughout the return stroke channel. After the first set of stepped leaders and return stroke, leader process again starts from the cloud. As the air column below is already partially ionized, the leader reaches the ground almost in a single or two steps. This is called ‘dart leader’. Thus, the return strokes subsequent to the first in a flash to ground are usually initiated by dart leader. In cloud portion, dart leader produces considerable radiation in VHF range. Pathak and Rajput (2005) calculated the magnitude of radiation in LF-VHF range, by integrating the electric field radiated throughout the dart leader channel.

 

Effect of lightning on Trees:

Lightning plays significant role in natural balance by determining the composition of trees in the most of the world’s forest as it is the cause of fire in the forests. Lightning is usually considered harmful, as it causes injuries to plants, animals and human beings. According to love (1970) frequent fires kept the California forest floor clean. Komarek (1968, 1973) is his study observed that the lightning strikes preferentially the taller trees and maintains balance between taller pines and the smaller oaks, which without lightning predator would be shaded from sunlight and die out. Von Lie, (1827); Chameides et al. (1977); Levine et al. (1984) explained that lightning produces many chemicals including nitrogen that would otherwise not be present in the atmosphere in such abundance at least. Lightning produces ozone through electrical excitation of oxygen molecule. The amount of ozone and nitrogen oxide that lightning create is greater than any other human activities in that level of the atmosphere. There is enough electrical energy in lightning to separate the nitrogen atom in the air, which further combines with the oxygen forming nitrogen dioxide, which reacts with water vapor and oxygen forming nitric acid. This falls to the earth along with the rain and combine with the minerals in the soil to form nitrates, a type of natural fertilizer. As the plant absorbs the nitrate and it is use to create chlorophyll, which help plant to go green. Chameides et al. (1977); Tie et al. (2002) in their study analysis that about 500 million tons of nitrogen fertilizer is synthesized by the thunderstorm in the world every year.

 

On the other hand, there is destructive part of the same fascinating phenomena. Lightning causes damage and destruction to ground based structures, trees, animals and people. Lightning strikes millions of trees every year. The probability of damage to plants by lightning is very high. The lightning effect varies with tree size and identity, and with the presence of lianas. Also, the trees morphology plays an important role in lightning effect.

 

Nelson (2008) studied, the damage to trees by lightning may be caused by the extreme heat and shockwaves generated by the current. The heat turns trees fluids into steam and burns its cells and tissues, which damage tree. The shock waves can cause the pith of a tree trunk to explode out through holes in the stem, which causes drop of fruits and can even split a tree trunk. He described the lightning injury to coconut palm may resemble coconut heart rot disease or root rots. Lightning strikes on banana may resemble Panama wilt disease and he also provided photographs of lightning injury to papaya, coconut palm, and banana trees in the eastern part of the island of Hawaii.

 

Betz et al. (2009); Rakov and Rachidi (2009) described that the human beings have invented various methods to deal with the adverse effects of lightning. Moore et al. (2000); Zeng et al. (2016) suggested that lightning rods are considered to be one effective method to reduce the injuries of lightning. During lightning process, strong current is guided into the soil through the lightning rod. Góra et al. (2021) during their research work examined 2,195 lightning damaged trees distributed among 93 different strikes. On average, each strike created canopy gap and caused wood biomass. Trees, lianas, herbaceous climbers and epiphytes were killed by lighting which is greater than their base line mortality rate. Gora et al. (2017); Gora & Yanoviak (2015); Yanoviak (2013) in their study provided the first quantitative mechanism, explaining the differences among trees can influence lightning- tree interaction and observed how lianas serve as natural lightning rods for trees and protect some trees by diverting electric current to their neighbors.

 

Komarek (1964); Stone and Chapman (1912) studied, the variation in electrical resistivity among trees is also expected to affect the amount of heating and maximum power experienced during lightning discharge. According to, Uman (2008), the amount of heating and maximum power is directly proportional to electrical resistance of the trees, which varies among tree species and their general morphology. The traits of trees likely influence the extent of damage occurring during lightning. Góra et al. (2017) observed that heating and maximum power decrease with increasing tree size (i.e., increase in height and diameter) and differ in their morphology and electrical resistivity and concluded that, lianas reduce heating and power within host trees by diverting electric current. Yaping et al. (2022), served the first report on the effect of lightning rods on soil properties, micro ecology and plant metabolism which promotes the understanding of the biological effects of lightning. They studied the effect of lightning on soil properties, microbial community and the active components of Pu-erh tea (Camellia Sinesisvar. assamica) near lightning rods and found that the contents of organic matter and available potassium, copper and calcium in rhizosphere soil were significantly higher, while the contents of total potassium, phosphorous, iron, magnesium, and aluminum decreased. Rakov and Rachidi (2009); Kotnik (2013); Gharaylou et al. (2020) suggested that lightning can affect soil properties, microbial communities and ultimately plant metabolism. Lightning can affect the content of ground pollutants and mediate the horizontal transfer of soil microbial genes, which ultimately affects the plant growth.

 

CONCLUSION:

As discussed, all fascinating constructive and destructive phenomena reveal the presence of huge energy in lightning. Lightning plays significant role in earth’s ecosystem. A lightning strike causes death, injuries to people, trees, and animals, damage and destruction to ground based structures. Several researchers have suggested that continuous strikes by lightning may have been the direct agent in the evolution of living organisms. On other hand it also synthesis nitrogen, effect the properties of soil which changes the plant metabolism and also affect the content of ground pollutants which effects ultimately the growth of plants.

 

In present work we have studied constructive as well as destructive both the parts of lightning phenomenon. From study of several researchers, we found that that about 500 million tons of nitrogen is synthesized by the lightning discharge, which is helpful for the growth of plants and to go them green. On the other hand, lightning is considered as forest predator. Every year many trees were listed died or may have been injured by lightning. There are many indications that lightning may weaken trees. However, the total percentage of lightning killed trees is no doubt higher than 25%, among which mortality rate of taller trees are greater. It is also observed that lianas protect some trees from lightning discharge by diverting electric current.

 

REFERENCES:

1.      Betz, H.D., Schumann, and Laroche, P.E. Lightning: Principles, Instruments and Application: Review of Modern Lightning Research. Heidelberg: Springer. 2009; 1-24. Doi: 10.1007/978-1-4020-9079-0.

2.      Chameides, W.L., D.H. Stedman, R.R. Dickerson, D.W. Rusch, and R.J. Cicerone.  NOX: Lightning and Biology. Atmos. Environ. 1984; 18, 1797-1804.

3.      Gharaylou M., Mahmoudian A., Bidokhti A.A., Dadras P.S.  Mutual relationship between surface atmospheric pollutants and CG lightning in Tehran area. Environ. Monit. Assess. 2020; 192.809.10.1007/s 10661-020-08739-8.

4.      Gora, E. M., Phillip M. Bitzer, Jeffrey C. Burchfield, Stefan Schnitzer. Effects of lightning on trees: A predictive model based on in situ electrical resistivity. Ecology and Evolution. 2017; 7(20). DOI: 10.1002/ece 3.3347.

5.      Gora, E.M., Bitzer, P.M., Burchfield, J.C., Gutierrez, C., and Yanoviak, S.P.  The contribution of lightning to biomass turnover, gap formation and plant mortality in a tropical forest. Ecology. 2021; 102: e03541. Doi: 10.1002/ecy.3541.

6.      Komarek, E.V. The natural history of lightning. Proceedings Tall Timbers Fire Ecology Conference. 1964; 3:139-183.

7.      Komarek, E.V. Lightning and lightning fires as Ecological forces. Proc. Annu. Tall Timbers Fire Ecol. Conf. 1968; 8: 169-197.

8.      Komarek, E.V. Introduction of Lightning Ecology. Proc. Annu. Tall Timber Fire. Conf. 1973; 13: 421-427.

9.      Kotnik T. Lightning- triggered electroporation and electrofusion as possible contributors to natural horizontal gene transfer. Phys. Life Rev. 2013; 10: 351-370. 10.1016/j.plrev.2013.05.001.

10.   Levine, J.S., T.R. Augustsson, I.C. Anderson, and J.M. Hoell: Tropospheric sources of NOX: Lightning and Biology. Atmos. Environ., 1984; 18: 1797-1804.

11.   Love, R.M. The rangelands of the Western United States. Sci. Am. 1970; 222: 88-96.

12.   Malan, D.J.  Les Decharges dans I’Air et la charge inferieure positive d’un nuage oraguex. Ann. Geophys. 1952; 8: 385-401.

13.   Malan, D.J. Les Decharges dans Les nuage oraguex. Ann. Geophys. 1955; 11: 427-434.

14.   Moore, C.B., Rison, W., Mathis, J., and Aulich, G. Lightning rods improvement studies. J. Appl. Meteorol. 2000; 39: 593-609. Doi: 10.1175/1520-0450-39.5.593.

15.   P.P Pathak and Shelly Rajput.Radiation from Dart Leader in LF-VHF range, Journal of Natural and Physical Sciences. 2005; 19(1): 75-80.

16.   P.P. Pathak and Shelly Rajput. Radiation due to stepped leader in higher frequency range during ground discharge, Journal of Natural& Physical Sciences, 2005; 19(2): 168-174.

17.   P.P. Pathak and Shelly Rajput. Signatures of Radiation due to Return Stroke in LF-VHF range during ground discharge, Research Journal of Engineering and Technology. 2021; 12(1): 12(1): 15-18.

18.   Rokav, V.A., and Rachidi, F. Overview of recent progress in lightning research and lightning protection. IEEE Transact. Electromagn. Comp. 2009; 51: 428-442. doi: 10.1109/TEMC.2009. 2019267.

19.   Scot C. Nelson. Lightning Injury to Plants. Plant Disease. July 2008. PD-40.

20.   Stone, G.E., and Chapman, G.H. Electrical resistance of trees. 24th Annual Report of the Massachusetts Agricultural Experiment Station. 1912; 31: 144-176.

21.   Tie, X., Zhang. R., Brasseur, G., and Lei, W. Global NOX production by lightning. J. Atmos. Chem. 2002; 43: 61-74. Doi: 10.1023/A:1016145719608.

22.   Uman, M.A. The art and Science of lightning protection. Cambridge, UK: Cambridge University Press. 2008

23.   Von Liebig, J. Une NOTE Sur la NITRIFICATION. Ann. Chem. Phys. 1927; 35: 329-333

24.   Wilson, C.T.R. On some determination of the sign and magnitude of electric discharges in lightning flashes, Proc. R. Soc. London Ser. A. 1916; 92: 555-574.

25.   Wilson, C.T.R.  Investigation on lightning discharge and on the electric field of thunderstorm, Philos. Trans. R. Soc. London SER. A. 1920:  73-115.

26.   Yaping Chen, Qiang Li, Wendou Wu, Xiaohui Liu, Jie Cheng, Xiujuan Deng, Xiaobo Cai, Wenxia Yuan, Jin Xie, Shihao Zhang and Baijuan Wang.  Effects of lightning on Rhizosphere Soil properties, Bacterial Communities, and Active Components of Camellia sinesis var. assamica. 2022. doi: 10,3389/fmicb.2022.911226.

27.   Yanoviak, S.P. Shock Value: Are lianas natural lightning rods? In M. Lowman, S. Devy, & T. Ganesh (EDS.), Treetops at risk: Challenges of Global Forest Canopies. 2013; 147-154. New York, NY: Springer.

28.   Yanoviak, S.P., Gora, E.M., Fredley, J., Bitzer, P.M., Muzika, R-M., and Carson, W.P. Direct effects of lightning in temperate forests: A review and preliminary survey in a hemlock- hardwood forest of the northern United States. Canadian Journal of Forest Research. 2015; 45: 1258-1268. https://doi.org/10.1139/cjfr-2015-0081.

29.   Zeng, R., Zhuang, C., Zhou, X., Chen, S., Wang, Z., Yu, Z., et al. Survey of recent progress on lightning and lightning protection research. High Voltage. 2016; 1: 2-10. doi: 10.1049/hve.2016.004.

 

 

 

Received on 07.08.2024            Accepted on 22.09.2024

©AandV Publications all right reserved

Research J. Engineering and Tech. 2024; 15(1):29-32.

DOI: 10.52711/2321-581X.2024.00005