Dynamic Decomposition of a Variety of Fungi

Yingzi Jiang

1,a,*

, Yuyan Zhang

1, b

, Yuchong Mao

2,c

and Tianhang Ji

1,d

1

Xuzhou Institute of mathematics and statistics, Xuzhou, Jiangsu, China

2

School of finance, Xuzhou Institute of Engineering, Xuzhou, Jiangsu, China

*Corresponding author:

a

fireyz@xzit.edu.cn

Keywords:

Multiple Regression Analysis Model, Biological Growth Kinetics, Lanchester Model, Fungi Community.

Abstract:

The carbon cycle describes the process of carbon exchange in the entire geochemical cycle and is an important

part of life on Earth. Part of the carbon cycle includes the decomposition of compounds so that carbon can be

updated and used in other forms. Based on the growth dynamics equation, this paper takes into account the

growth rate of fungi and the humidity resistance of fungi, establishes a multi-regression model and a

Lanchester model, analyzes the decomposition of various fungi on wood fibers, and expounds the role of

fungi in the ecosystem.

1 INTRODUCTION

1.1 Problem Background

Ground litter, also known as organic debris, refers

toall organic matter produced by biological

components in an ecosystem and eventually returned

to the surface of the land (LI 2016). It is the main

carrier of energy flow and material circulation above

and below ground (Wardle 2004). The carbon cycle

refers to a process in which carbon elements are

exchanged in four circles throughout the earth, as

shown in Figure 1:

Figure 1: Carbon cycle.

As the decomposers of organic matter in the

ecosystem, fungi play an essential and critical role in

the decomposition of ground litter.

2 MATERIALS AND METHOD

The growth and decomposition of microorganisms

such as fungi are also affected by temperature,

862

Jiang, Y., Zhang, Y., Mao, Y. and Ji, T.

Dynamic Decomposition of a Variety of Fungi.

DOI: 10.5220/0011298500003443

In Proceedings of the 4th International Conference on Biomedical Engineering and Bioinformatics (ICBEB 2022), pages 862-866

ISBN: 978-989-758-595-1

Copyright

c

inoculation amount, electric field intensity and other

conditions (Kong 2001).

2.1 The Classification of Fungi

When studying the growth process on the interface of

fungi, logical models are often used to describe the

growth dynamic equation of fungi (Jin 1989).

1

n

X

m

dX X

X

dt X

β











=−













(1)

Where t is time, X is the biomass per unit area,

and Xm is the maximum biomass per unit area is the

growth rate constant.

2.1.1 Factors That Affect the Rate of Fungal

Decomposition

In order to rapidly degrade ground litter with fungi

that have different hyphae elongation and moisture

tolerance, it is necessary to ensure that temperature,

humidity, pH and other conditions are maintained

under appropriate conditions (Xue 1999).

Figure 2: Lignin degradation diagram.

2.1.2 Establish Multivariate Nonlinear

Regression Model

Based on the fungal decomposition rate and

humidity, temperature and acidity as arguments, a

nonlinear regression model is established:

()

01 1 2 3

2

,, , ; , ,

0,

m

i

zfbb byyy

N

εσ

=















(2)

Where,

ε

is the random error term. In order to

minimize the square sum of the error between the

sample data of fungi decomposition rate and the

estimated fungi decomposition rate, the least square

method was used in parameter calculation in this

paper to minimize the error. That is:

()



()

2

01

1

min , , ,

n

mii

i

Rb b b z z

=

=−





(3)

Where,



()

01 1 2 3

=,,,;,,

imiii

zfbb byy y

is an

estimate of the rate of fungal decomposition.

Through data observation, it can be found that the

fungi decomposition rate has a non-linear

relationship with each index. Therefore, this paper

uses SPSS software to curve-fit each index and the

fungi decomposition rate, and uses quadratic,

logarithmic, and exponential functions for analysis.

Take the fitting figure 3 of the decomposition rate of

Armillaria as an example:

Figure 3: Relationship fitting grap.

Dynamic Decomposition of a Variety of Fungi

863

Therefore, the multivariate nonlinear regression

model of decomposition rate of Armillaria mellea and

environmental influencing factors can be obtained by

solving SPSS as follows:

222

1231 2 3

16.992 0.107 0.593 1.16 0.003 0.016 0.105yxxxxxx=+ − ++ + −

According to the above method analysis, it can be

found that different species and even different fungi

are affected by temperature, humidity, pH and other

environmental factors. Relatively speaking, the

higher the temperature, the faster the fungus breaks

down wood.

2.2 The Interaction of Fungi

The rate at which withpositor and wood fibers break

down depends not only on the type, characteristics

and environment of the fungus, but also on the

competition of the fungus's growth process

(Tadashi

2010).

2.2.1 Internal Competition for Fungi

According to the symmetrical fork model, the total

NA node for each active bud tube growing on the

interface is and the total number of growth segments

is determined by the number of active segments.

According to biological research, the proportion of

active organisms in total biomass is 33%. Available

based on growth dynamics equations:

3

TT

XA X

dX X

X

dt

ββ

==

(4)

For

T

X

, according to the definition of growth rate

and combined with the above equation, take the pair

to get (Lu 2016):

0

ln ln

3

X

T

X

Xt

β

=+

(5)

Based on the growth model of microorganisms in

the growth of several years, the growth state of the

fungus can be obtained during this period, so that the

performance of the fungus in the competitive process

can be studied.

When fungi are full on the interface, myceliums

collide with each other during growth, leading to

competition of substances and rendering some

mycelium inactive. The proportion of inventory will

decrease in a pair after the competition of mycelium:

()

0.33

kt t

v

FLe

α

−−

= . When

tt

α

=

,

TE

XX=

stop

growing, combined with the growth process of fungi,

can get the fungus internal competitive model:

()

0

ln 1

3

kt t

TX

E

XL

e

Xk

β

−−



=−



(6)

According to the establishment of the internal

competitive model of fungi, we can understand the

growth and development of fungi. when

environmental factors such as temperature and

humidity are in the optimal growth environment of

fungi.

Figure 4: Growth curve fitting of Armillaria.

We can see that in the process of separate growth

of Armillaria, the interaction of the fungi is in an

internal competition relationship. But competition

among fungi isn't just internal competition due to

growth interface constraints.

2.2.2 External Competition of Fungi

The Lanchester equation is mainly used to predict the

fighting situation of the two sides, this article

compares the competition of multiple fungi to multi-

army combat to obtain related models:

ICBEB 2022 - The International Conference on Biomedical Engineering and Bioinformatics

864

()

dx

cy x u t

dt

dy

dx y v t

dt

α

δ



=− − +







=− − +





(7)

Among them, and represent the attack power of

both sides of the competition,

α

and

δ

represent the

non-competitive damage factor of both sides of the

competition,

()

ut

and

()

vt

represent the number of

fungi regenerated by fungi.

The development of each fungus is in an

internalcompetition link because the interface has not

been overgrown in the early stage.

3 RESULTS & DISCUSSION

3.1 Fungi Are Affected by the

Environment

The fluctuation of the environment means that the

temperature and humidity that were originally

suitable for fungi growth will also change

accordingly, causing the growth and competition of

fungi to be affected to a certainextent, so this article

mainly considers the influence of environmental

fluctuations on the external competition of fungi.

1kk

F

dF

tT

+

−

=

(8)

Obtain the effect of the introduction of

environmental factors on the state equation:

*

1kk

F

AF C

+

=⋅+

. By adding the state equation

to the analysis of the fungus's external competition,

the following new Lanchester equation can be

obtained:

'

cA

F

EAF C=+

(9)

The growth and development of Armillaria

gallica, Armillaria tabescens and other fungi in arid

environments are much lower than the development

of tropical rain forest environments.

3.2 The Importance of the Diversity of

Fungal Communities

The rate at which fungi break down can be compared

to the amount of wood the fungus eats, creating

anOlsen model to break down fallen objects:

0

100% 100%

zt

t

P

RP e

P

−

=× = ×

(10)

Among them,

z is the decomposition rate of

garbage,

t

P

is the quality of falling material at the

moment, and

0

P

is the initial mass of falling material.

Among them, RP is the residual rate of withering

material.

A diagram of the amount of withering material

left over from the individual and co-action of chicken

honey ring bacteria, sequined honeycella and other

bacterial species was solved:

Table 1: Mass residual rate after decomposition.

Single

strain

Two

strains

Three

strains

Four

strains

0 1 1 1 1

1 0.95 0.94 0.94 0.93

2 0.89 0.87 0.83 0.85

3 0.83 0.81 0.79 0.69

4 0.77 0.74 0.73 0.53

5 0.71 0.67 0.68 0.47

6 0.65 0.61 0.55 0.32

7 0.59 0.54 0.47 0.27

8 0.53 0.47 0.39 0.19

9 0.47 0.41 0.23 0.13

10 0.41 0.34 0.13 0.08

Based on the above figure, it can be seen that

when Armillaria gallica, Armillaria tabescens and

other fungi act alone, the decomposition rate of

ground drop and wood fiber is slower than that of the

fungus group and the four fungi community. The

quality of the litter More residual rate. For this reason,

the diversity of fungi communities is beneficial to the

Dynamic Decomposition of a Variety of Fungi

865

decomposition of ground litter and wood fiber by

fungi.

4 CONCLUSIONS

As a decomposer in the ecosystem, fungi are also a

key component of the entire planet's carbon cycle.

There are many types and different shapes, and the

environments in which different fungi live are also

diverse. The growth mode of fungi is similar to that

of plants, and the way of nutrient intake is similar to

that of animals. It takes in the nutrients necessary for

life by decomposing organic matter into simple

substances that plants can absorb and use.

In fact, not only do fungi maintain plant

biodiversity in the soil, but plant diversity also acts on

fungi diversity. Studies have shown that fungi

diversity and plant diversity have a significant

positive correlation, and fungi diversity increases, the

fungi community can cooperate with each other to

help plants obtain more resources and nutrients, and

reduce nutrient competition(Wang 2020).

All in all, rich and diverse fungi are an

indispensable part of the earth. Fungi promote the

development of biodiversity in the ecosystem.

Biodiversity is also conducive to the development of

fungi diversity. The two develop in a balanced

manner to form a mutually beneficial and win-win

situation.

ACKNOWLEDGEMENTS

This paper is one of the phased achievements of the

general project of National Natural Science

Foundation of China, "Research on stability analysis

and stabilizing controller design of semi Markov

switched systems" (12071408).

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