Degradation Efficacy of Pinus radiata Don Needle Leaf …
89
1.2 Decomposition
Litter decomposition is a fundamental process to ecosystem, responsible of carbon
and nutrient cycling. The chemical composition and the structural characteristics
of litter determines the “decomposability” resulting in fast or slow degradation and
the fraction of recalcitrant residue that determine the buildup of soil organic matter
(Berg and McClaugherty 2008; Baldrin and Lindahi 2017). Decomposition process
of leaf litter is generally divided into early and late stages with different dominant
organic chemical components limiting the decomposition rate. In the early stages of
decomposition soluble components decay or are leached away very rapidly; cellulose
and hemicellulose decompose faster in nutrient rich versus nutrient poor litter; thus
the length of the early stage may range from a few months to more than a year. As
litter decomposes, concentrations of lignin and nitrogen (N) increase (Berg et al.
1997). Litters with low initial nitrogen concentration may accumulate more nitrogen
than those with a high level (Hobbie and Vitousek 2000; Pirjo Koivusarri Mysore
et al. 2019). Site factors also contribute to nitrogen immobilization into decomposing
litter and nitrogen accumulation in litter may be enhanced by soil N levels (Virzo
De Santo et al. 1998; Sun et al. 2020). Fungi are the best-known microorganisms
capable of degrading these three polymers. The substrates being insoluble and fungal
degradation have to occur exocellularly, either in association with the outer cell
envelope layer or extracellularly.
The present work is focused on the degradation efficacy of Pinus radiata Don,
needle leaf, twig and bark by wood degrading fungi in forest ecosystem. The name
of the Fungi are Colricia perennis, Heterobasidium annosum, Polyporus squamosus,
Thelophora terrestris.
2 Materials and Methods
2.1 Study Area
The area of the study for this research work was identified based on the undisturbed
virgin forest ecosystem of Doddabetta, Nilgiris, Tamil Nadu, India, which is 86 km
from Coimbatore situated at 11°24
08.7° N and 76°44
12.2° E with a elevation of
8652 ft (2637 m) and 9 km from Ooty town (Satellite Images-Fig. 1). The area
surrounding Doddabetta is mostly forest, Sholas cover the hollows of its slopes,
which receives both South-west and North-east Monsoon rains. The average Southwest Monsoon rain fall 900–1050 mm, the average North-east monsoon rain fall
350–450 mm. The present research work was carried out with the Gymnosperm
forest Pinus radiata Don. of Doddabetta, Nilgiris, India (Fig. 1).
89
1.2 Decomposition
Litter decomposition is a fundamental process to ecosystem, responsible of carbon
and nutrient cycling. The chemical composition and the structural characteristics
of litter determines the “decomposability” resulting in fast or slow degradation and
the fraction of recalcitrant residue that determine the buildup of soil organic matter
(Berg and McClaugherty 2008; Baldrin and Lindahi 2017). Decomposition process
of leaf litter is generally divided into early and late stages with different dominant
organic chemical components limiting the decomposition rate. In the early stages of
decomposition soluble components decay or are leached away very rapidly; cellulose
and hemicellulose decompose faster in nutrient rich versus nutrient poor litter; thus
the length of the early stage may range from a few months to more than a year. As
litter decomposes, concentrations of lignin and nitrogen (N) increase (Berg et al.
1997). Litters with low initial nitrogen concentration may accumulate more nitrogen
than those with a high level (Hobbie and Vitousek 2000; Pirjo Koivusarri Mysore
et al. 2019). Site factors also contribute to nitrogen immobilization into decomposing
litter and nitrogen accumulation in litter may be enhanced by soil N levels (Virzo
De Santo et al. 1998; Sun et al. 2020). Fungi are the best-known microorganisms
capable of degrading these three polymers. The substrates being insoluble and fungal
degradation have to occur exocellularly, either in association with the outer cell
envelope layer or extracellularly.
The present work is focused on the degradation efficacy of Pinus radiata Don,
needle leaf, twig and bark by wood degrading fungi in forest ecosystem. The name
of the Fungi are Colricia perennis, Heterobasidium annosum, Polyporus squamosus,
Thelophora terrestris.
2 Materials and Methods
2.1 Study Area
The area of the study for this research work was identified based on the undisturbed
virgin forest ecosystem of Doddabetta, Nilgiris, Tamil Nadu, India, which is 86 km
from Coimbatore situated at 11°24
08.7° N and 76°44
12.2° E with a elevation of
8652 ft (2637 m) and 9 km from Ooty town (Satellite Images-Fig. 1). The area
surrounding Doddabetta is mostly forest, Sholas cover the hollows of its slopes,
which receives both South-west and North-east Monsoon rains. The average Southwest Monsoon rain fall 900–1050 mm, the average North-east monsoon rain fall
350–450 mm. The present research work was carried out with the Gymnosperm
forest Pinus radiata Don. of Doddabetta, Nilgiris, India (Fig. 1).