Saplings

The

density

^of

saplings

^was

higher

^thanthatof

seedlings,

^withan estimated 2147

saplings ha"1

and2012

saplings ha"1

in October 1997 and March 1999

respectively.

^{Thedifferenc¬}

esbetween therecorded densities for thetwoseasons werenot

significant (Table

3.4).^As for

seedlings, saplings

^{weredominated}

by species

^{of the}

pioneer

group.The

pioneer

group

represented

^about91.34% and 95.36% of the total

saplings

in October 1997 and March 1999

respectively.

^The

primary

group formed about 6.57% and 3.38% of the

seedling population

in October 1997 and March 1999

respectively,

^{while the}

secondary

group^con¬

tributed

only

2.10% and 0.951% to the total

sapling population

^{in October 1997 and} March 1999

respectively. Overall, sapling composition

^{was dominated}

by Symplocos,

which made_upabout 58.51% ofthe total

population

in October 1997 andabout64.94%

in March 1999

(Table 3.7).

Damage

^tothe

saplings

^{was limitedtothe}

pioneer

group. InOctober

1997, only

^about

1.19% of total

saplings

^showed

signs

^of

lopping

^or

topping,

whereas in March 1999 about 11.47% of

saplings

had been either

lopped

^or

topped (Table 3.8).

^{In October}

1997,

^about 4.2% of Viburnum

saplings

^{and about 1% of}

Symplocos seedlings

^were

damaged. By

March 1999, about54.54-% of

Daphniphyllum saplings

^{had been}

damaged

^followed

by

Viburnum

(15.78%), Symplocos (9.54%)

^and

Eurya (4.76%).

Increased incidences of

lop¬

ping

^and

topping

^of

saplings

^{were attributed to}indiscriminate

felling

^for

poles

^andfuel-

wood,

^as construction ofa

housing complex

^{for the}

hydro-electric project

^had

recently

startedonthenortheast

aspect.

44

Group/Genus Saplings

October 1997 Saplings ^{March 1999}

Total ha"1 % Total ha"1 %

Primary

^{141.02 6.57 74.10 3.38}

Quercus 6.41 0.30 36.41 0.32

Elaeocarpus ^{6.41 0.30 0.00 0.00}

Castanopsis ^{6.41 0.30 6.41 0.32}

Persea 70.51 3.28 29.23 1.45

Cinnamomum 51.28 2.39 32.05 1.59

Secondary

^{44.87 2.10 19.23 0.95}

Rhus 12.82 0.60 6.41 0.32

Turpinea ^{12.82 0.60 6.41 0.32}

Ficus 19.23 0.90 6.41 0.32

Pioneer 1,961.54 91.34 1,919.49 ^95.36

Daphniphyllum ^{76.92 3.58 70.51 3.50}

Eurya ^{166.67 7.76 147.23 7.31}

Viburnum 455.13 21.19 388.20 19.29

Symplocos 1,256.41 ^58.51 1,307.14 ^64.94

Casaeria 6.41 0.30 6.41 0.32

TOTAL 2,147.44 ^100.00 2,012.82 ^100.00

Table 3.7 Numberofsaplings (no

ha'1)

bygroup/genus ^on the northeastaspect ⁱⁿ October1997 and March 1999.

Genus October 1997 March 1999

Total

ha"1

_Damaged

ha"1

^Damaged%

Total

ha"1

_Damaged

ha"1

^Damaged%

Eurya 1,667.67 0.00 0 134.62 6.41 4.76

Daphniphyllum ^{76.92 0.00 0} 70.51 38.46 54.54

Viburnum 455.13 19.23 4.2 365.38 57.69 15.78

Symplocos 1,256.41 ^{6.41 0.51} 1,343.10 ^{128.21 9.54}

TOTAL 2,147.44 25.64 1.19 2,012.82 ^230.77 11.47

Table 3.8 Number ofdamaged saplings (no

ha"1)

by genus^onthe northeastaspect ⁱⁿ

October1997and March 1999.

3.1.3 Forest stands

The average number of^{trees was} estimated ataround 238 trees

ha"1 _(±46.33

trees

ha"1)

and the

corresponding

gross volume ^at363

m3 ha"1 _(±97.44 m3 ha"1).

^The

primary

spe¬

cies group, which made up about 40.46% of total trees and about81.68% oftotal forest

gross volume dominated^theupper

canopies (Table

3.9). ^A

relatively high

number of the

pioneer

group

occupied

the lower canopy

(48.51%),

^butits

corresponding

gross^volume

wasverylow,

making

up

only

^{about 1.29%} of total gross volume. The contributionofthe

secondary

group^{to the totalnumber andtotal} gross volume of^theforestwas

relatively

low, with valuesof 11.02% and7.75%

respectively.

Distribution oftreesinthe stand ap¬

peared normal,

^{with a}

higher

^{number oftrees}in the lower diameter classes

(Figure 3.5).

However,

^{the mean volume}per

species figures

^{indicatedthat lowerdiametertrees were}

represented mainly by

^the

pioneer

group

(0.33

^m

/tree)

^{while treeswitha}

larger

^diameter

were

represented by

^the

primary

group

(3.07

^m

/tree). Large

^trees

contributing

^tothe

high

volumewere

mainly Quercus (11.07

^m

/tree),

^{Alcimandra (4.88m}

/tree),

^Sloanea

(4.87 m3 _tree). Castanopsis (4.63 m3/tree), Elaeocarpus (4.55 m3/tree)

^{and Tooria}

(4.22m3/tree).

Genus Density ^Volume Mid-stem vol¬

ume(m3tree"1)

Stemha"1 % m3ha"1 %

Primary ^{96.2 40.46 296.14 81.68 3.07}

Lithocarpus ^{0.54 0.23 0.14 0.04 0.25}

Magnolia ^{0.81 0.34 0.38 0.10 0.47}

Toona 0.27 0.11 1.14 0.31 4.22

Sloanea 0.54 0.23 2.63 0.73 4.87

Alcimandra 0.54 0.23 2.64 0.73 4.88

Prunus 1.08 0.45 3.24 0.89 3.00

Nyssa ^{3.51 1.48 4.35 1.20 1.24}

Michelia 0.81 0.34 1.32 0.36 1.62

Acer 14.05 5.91 31.46 8.68 2.24

Castanopsis ^{11.08 4.66 51.30 14.15 4.63}

Persea 39.73 16.70 61.57 16.98 1.55

Quercus 8.92 3.75 98.72 27.23 11.07

Cinnamomum 7.03 2.96 12.98 3.58 1.85

Elaeocarpus ^{3.78 1.59 17.20 4.75 4.55}

Beilschmiedia 3.51 1.48 7.07 1.95 2.01

Secondary ^26.2 11.02 28.04 7.75 1.07

Evoda 1.62 0.68 0.16 0.04 0.10

Brassaiopsis ^0.54 0.23 0.21 0.06 0.38

Viburnum 4.59 1.93 0.26 0.07 0.06

Casaeria 1.08 0.45 0.81 0.22 0.75

Rhododendron 0.54 0.23 1.14 0.32 2.11

Eriobotrya 2.16 0.91 1,16 0.32 0.54

Turpinea 1.89 0.80 2.05 0.57 1.09

Ficus 3.24 1.36 2.56 0.71 0.79

Rhus 0.54 0.23 0.07 0.02 0.13

Amoora 5.14 2.16 7.54 2.08 1.47

Unknown 2.43 1.02

5.141

1.42 2.11

Macropanax ^2.43 1.02 6.94 1.92 2.85

Pioneer 115.41 48.51 38.42 1.29 0.33

Eurya ^12.43 5.23 4.66 1.29 0.38

Symplocos 86.49 36.36 22.27 6.14 0.26

Walsura 0.27 0.11 0.04 0.01 0.13

Maesa 1.08 0.45 0.06 0.02 0.05

Daphniphyllum 15.14 6.36 11.39 3.14 0.75

TOTAL 237.84* 100.00 362.58** 100.00 1.52

Standarderrors 22.84 ^. 48.04

Table 3.9

Species composition, density

^and

growing

^{stockonthe northeast}aspect.

46

Diameterclass(cm)

Figure^{3.5 Number}of trees and

standing

volume per hectare^on the northeastaspect.

About14trees

ha"1, corresponding

^to5.8%of

standing

^treesin the northeast

aspect,

^were either

lopped

^or

topped (Table 3.10). Secondary

group ^trees

(18%)

^weremost

heavily lopped,

^followed

by

the pioneer group

(8%)

and the primary group

(4%). Heavily lopped

trees

(>10%

^{of their}

totals)

^{wereMichelia, Prunus and}

Macropanax followedby

^Amoora,

Ficus, ^{Evoda and}

Daphniphyllum.

^Farmers

lopped

^treesfor fodder and

topped

^lower-di¬

ameter treesfor fence

poles

^{andfuel-wood.}

Symplocos Eurya, Viburnum,

^Cinnamomum and Michelia

might

^{have been}

lopped

^or

topped

^for

poles

^and

fuel-wood,

^while

Ficus,

^Ac¬

er,

Amoora, Castanopsis,

^Evoda,

Macropanax

^{and Prunus}

might

^{have been}

lopped

^for

fodder.

Group/^{Genus Total} Density (stemha'1)

Lopped

Stemha ^' %

Primary ⁹⁶ 3 4

Acer 15 0 28 1 8

Castanopsis 11 0 27 24

Michelia 1 0 27 270

Prunus 1 0 27 27 0

Persea 39 1 62 41

Cinnamomum 7 0 54 77

Secondary ^{26 2} 18

Ficus 3 0 54 18

Macropanax ² 0 54 27

Evoda 2 0 27 14

Amoora 5 0 81 16

Pioneer 116 9 8

Eurya 12 0 81 7

Daphniphyllum ^{15 1 62} 11

Viburnum 5 0 27 6

Symplocos ⁸² 5 94 7

TOTAL 238 14 58

Table3.10 Lopped ^trees

by group/genus

^on the northeastaspect^{of the}

study

^area.

3.2 Assessment of

vegetation

^on the southwest

aspect

^{of the}

study

area in October 1997 and March 1999

3.2.1 Ground

vegetation

Forbs andshrubsmade_upthe bulk of

ground vegetation

^{mbothseasons. Therewasmore} forb/shrub coverage in October

1997,

whereas grass coverage ^was sparserⁱⁿOctober

1997. The numberofsmall tree

seedlings

^{wasthe same inOctober 1997}and March 1999

(Figure

^3.6).

70

g

⁶⁰

£

⁵⁰

g

⁴⁰

?

³⁰

B

²⁰

CO

<° 10 EC ^U

0

13shrubs/forbs grasses

HSmall tree

seedlings

October 1997 March 1999

Figure ^{3.6 Ground}

vegetation

^onthe southwestaspect ^{inOctober 1997 and} March 1999.

3.2.1.1

Grasses

Paspalum

^and

Digitaria

constituted the main grass

population.

^{Thenumber of}

Digitaria

recorded in October 1997 was

significantly higher

^{thaninMarch 1999}

(Table 3.11).

^The

numberof

Kikiyu

^{recordedmthetwo seasonsdidnotdiffer}

significantly.

^Someunknown

grasses and

sedges

^{were recordedinboth seasons}

(Figure 3.7)

^and their numbers re¬

mained

reasonably

^constant. The number ofbamboo recordedmOctober 1997

appeared

tobe greater^{than inMarch 1999 butthis also did notdiffer}

significantly.

70

-, 60

CO

<e so

o o o 40 3* ³⁰

w

g ²⁰

Q 10

0

_ ® October 97

--'D

March 99

f—i .»si L

Dgitana Paspalum Kikiyu Grass types

Barrboo Unk grass

Figure^{3.7 Grass}types^{on thesouthwest}aspect ^{in October 1997 and}March 1999.

48

Grass types October 1997 (df=36) ^{March 1999} (df=36) ^t-value P

Digitaria 70,202.70 ^{51418.92 2.01} 0.05

Paspalum 21,351.35 13,648.65 ^{1.04 0.30}

Kikiyu 7,905.41 8,581.08 ^1.00 0.32

Bamboo 4,189.19 2,770.27 ^{2.39 0.17}

Unknowngrass 3,783.78 4,864.86 ^{0.74 0.74}

TOTAL 107,432.433 81,283.78 1.69 0.10

(Boldpvalue=significant, df=degree ^offreedom)

Table 3.11 Paired samples^{tteston mean} density

(no ha"1)

^ofthe grasses by types^for

October 1997vs March 1999 with 37 plots^on the southwestaspect.

3.2.1.2 Forbs/shrubs

The

palatable

group madeup ^{the main}forb/shrub

population,

^followed

by

"other"forbs/

shrubs and the

unpalatable

group. The^numberof

palatable

and "other" groups in March 1999was lower thaninOctober 1997

(Figure 3.8).

The total number of shrubs and forbs recordedinOctober 1997 differed

significantly

^{fromthatin March 1999. The}

significant¬

ly higher

^{numbers of}

^Pilea,

Rubus and Ptericanthus recorded in October 1997

compared

toMarch 1999 contributedtothe

significant

difference inthe total numberof forbs/shrubs

(Table 3.12).

The number of Viola and Pilea that

usually

grew under the forest canopy

wasless in March 1999than in October 1997. This indicated that

grazing

^{had been}

heavy

asit had extended into the forests. The presence of

non-palatable Eupatorium, Pteridium, Ageratum

^{andArtemisiafurtherconfirmedthat the}

quality

^of

forage

^was

declining.

140

<S 120

i

^{ioo -}

o

° 80

5

⁶⁰

'1

⁴⁰

cu

Q 20 ^-

0 ^--

Palatable Unpalatable Others

Group

Figure^3.8 Forbs/shrubs by group^{on the}southwestaspect ⁱⁿOctober 1997and March 1999.

^October 1997 D March 1999

Genus October 1997

(df=36)

^{March 1999}(df=36) ^t-value P Palatable

Viola 19,497.50 10,710.61 1.58 0.12

Pilea 41,791.89 15,351.35 2.74 0.01

Rubus _{878.48 201.50 2.71 0.01}

Gerardinia 1,351.55 643.24 1.95 0.06

Labiatae 202.70 0.00 1.36 0.19

Elatostema 64,114.00 50,762.00 ^1.00 0.32

Persicaria 135.00 _0.00 1.00 0.32

Solarium 0.00 135.00 1.00 0.32

Aconogonum 4,932.43 4,697.20 ^0.13 0.90

Unpalatable

Pteridium 26,636.76 21,540.42 ^1.37 0.18

Ptericanthus 6,251.55 643.24 3.74 0.001

Eupatohum 4,439.56 1,769.17 1.09 0.28

Plantago

10,205.51 5,910.81 ^1.07 0.29

Ageratum

^338.84 67.47 1.00 0.32

Artemisia 405.41 0.00 1.00 0.32

Others

Unknown shrubs _{202.57 202.57} 0.00 1.00

Rauwolfia 3,210.81 2,838.51 0.50 0.29

TOTAL 184,594.59 115,472.97 ^3.94 0.001

(Bold

p

value=significant, df=degree

^offreedom)

Table 3.12 Pairedsamples^{t teston mean}

density

^offorbs/shrubs

(no ha"1)

bygenus for October 1997vs March 1999 with 37plots ^on the southwestaspect.

3.2.1.3 Small tree

seedlings

The

pioneer

group dominated _{the young}tree

seedling population,

^while

primary

^{and sec¬}

ondary

groups hadsmall

populations (Figure 3.9).

^{The total} number of smalltree seed¬

lings

recorded inOctober 1997 and March 1999 didnot differ

significantly (Table 3.13).

There didnotappear^tobea trendas

regards

^theappearance ^and

disappearance

^ofyoung

tree

seedlings during

^{the tworecorded seasons.}

50

Primary Secondary ^Pioneer Group

Figure

^{3.9 Smalltree seedlings}

by

group^onthe southwest aspectin October 1997 and March 1999.

A few generasuch as

Pentapanax, Elaeocarpus,

^Acerand Caeseria which werenotre¬

corded inOctober 1997 had

appeared by

^{March 1999 while}Beilschmiedia, Schima and Viburnum whichwererecordedin October 1997 had

disappeared by

March 1999. There

werefewer

Macaranga,

^{Persea, Lindera}and Emya inMarch 1999 than inOctober

1997,

whereas the numberof

Symplocos

^was

higher

^{inMarch 1999 thanin} October 1997.

Genus October1997 (df=36) ^{March 1999}(df=36) ^t-value P

Primary

Acer 0.00 135.14 1.43 0.16

Elaeocarpus ^{0.00 67.57 1.00 0.32}

Schima 67.57 0.00 1.00 0.32

Beilschmiedia 135.14 0.00 1.43 0.16

Persea 203.07 67.57

^_^

0.16

Secondary

Pentapanax 0.00 135.14 1.43 0.16

Macaranga ^270.27 67.57 1.00 0.32

Pioneer

Caesaha 0.00 135.14 1.43 0.16

Symplocos 135 14 608.11 1.74 0.09

Eurya 81081 405.41 1.29 0.21

Lindera 743.24 67.57 1.22 0.23

Viburnum 67.57 0.00 1.00 0.32

TOTAL 2,432.43 1,689.18 ^0.88 0.38

(Boldp

value-significant, df=degree

^offreedom)

Table 3.13 Paired samples^{t teston mean} density (no

ha"1)

of small treeseedlings by genus for October 1997^vs March 1999 with 37 plots^{on thesouthwest}aspect.

No documento Cattle grazing - an integral part of broadleaf forest management planning in Bhutan (páginas 44-52)