International Journal of Forestry Research

Volume 2014 (2014), Article ID 140926, 16 pages

http://dx.doi.org/10.1155/2014/140926

Research Article

Ecological Features of Cultivated Stands of Aquilaria malaccensis Lam. (Thymelaeaceae), a Vulnerable Tropical Tree Species in Assamese Homegardens

P. Saikia¹ and M. L. Khan²

¹Centre for Environmental Sciences, Central University of Jharkhand, Brambe, Ranchi, Jharkhand 835205, India

²Department of Botany, Dr. Hari Singh Gour Central University, Sagar, Madhya Pradesh 470003, India

Received 10 February 2014; Accepted 22 June 2014; Published 8 July 2014

Academic Editor: Sunil Nautiyal

Copyright © 2014 P. Saikia and M. L. Khan. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract.

Research was conducted in twenty-seven selected villages located in Jorhat and Golaghat districts of upper Assam, northeast India, for population estimation, quantitative ecological analysis, and evaluation of Aquilaria malaccensis (Thymelaeaceae). Vegetation sampling was done by quadrat method and A. malaccensis is the most dominant tree species in all twenty-seven different study sites of upper Assam contributing 10–54% of the total tree density with a mean of . Density of the species varied from 6,236 individuals ha⁻¹ to 429 individuals ha⁻¹ with a mean of 1,609 individuals , whereas frequency of occurrence is very high ranging from 93% to 100% with a mean of in different study sites. Distribution of A. malaccensis is found contagious in all twenty-six study sites on the basis of abundance to frequency ratio except in KBG, Golaghat, where its distribution is random with 0.04 abundance to frequency ratio. The widespread cultivation of A. malaccensis in upper Assam, northeast India, offers a potential ex situ reservoir for the future conservation and management of this threatened tree.

1. Introduction

Aquilaria malaccensis (Thymelaeaceae), locally known as “Sanchi ” or “Agaru ” in Assamese, is an evergreen tropical forest tree highly priced for its resin or agarwood. The species is valued in many cultures for centuries because of its distinctive fragrance and used extensively in incense, perfume, and traditional medicine. Natural populations of Agaru are distributed in south and southeast Asia and in India; it occurs mostly in foothills of northeastern region (Assam, Arunachal Pradesh, Nagaland, Meghalaya, Mizoram, Manipur, and Tripura) as well as West Bengal [1]. However, large scale harvesting of the species from natural population caused rapid depletion in the wild and is listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) in 1994 [2]. The species is “vulnerable” globally according to the current IUCN red list [3]. On the other hand, Agaru is extensively cultivated in homegardens of upper Assam and contributes significantly up to 20% of the total annual income of the family with a mean of to the economy of the local people [4]. A good population stock of Agaru with highest density and frequency in homegardens of upper Assam was also reported by Saikia et al. [5]. Two distinct morphs of Agaru (Bhola Sanchi and Jati Sanchi) are cultivated in homegardens of upper Assam with different life form characteristics [6]. Bhola Sanchi is fast growing and less agarwood yielding than the other variant Jati Sanchi which is slow growing but high agarwood yielding and preferred for commercial cultivation. Nath and Saikia [7] also reported similar variations among the population of Agaru growing in homegarden and they identified three “races” from different areas of Assam. According to them, “variant I (RRLJ 2729)” is a medium sized tree with slender trunk, oblong-lanceolate leaves known as Bhola Sanchi; “variant II (RRLJ 2726)” is a large sized tree with obovate lanceolate leaves known as Sanchi; “variant III (RRLJ 2730)” is a much branched small to medium sized tree with lanceolate leaves known as Jati Sanchi.

Quantitative inventories help in identifying species that are in different stages of vulnerability as well as various factors that influence the existing vegetation in any region [8, 9]. Considering the scarcity of information on Agaru cultivation in homegardens of upper Assam, we attempted to study the ecological features, mainly, the quantitative characteristics of A. malaccensis Lam. in homegardens of upper Assam, northeast India.

2. Materials and Methods

2.1. Study Sites

The study was conducted in twenty-seven selected villages located in Jorhat and Golaghat districts of upper Assam, northeast India (25°48′ to 27°10′ N and 93°17′ to 94°36′ E) (Figure 1). The site is surrounded by Sibsagar and Dibrugarh districts on the east, Nagaon and Karbi Anglong districts on the west, Lakhimpur and Sonitpur districts on the north, and the bordering state of Nagaland on the south. The total numbers of villages of Jorhat and Golaghat districts are 855 and 1089 with population density of 354 and 236 individuals per square kilometer, respectively [10]. The climate of the study area is classified as tropical type having distinct hot and humid summer (34.0°C during June-July) and cool winter (10.0°C during December-January). The mean annual rainfall of Golaghat and Jorhat districts ranges between 1200 mm and 1900 mm. The relative humidity remains very high throughout the year [11].

Figure 1: Map of Golaghat and Jorhat districts of upper Assam, NE India, showing the locations of the study sites.

2.2. Vegetation Analysis

A total of twenty-seven different sites (16 from Golaghat and 11 from Jorhat district) of Jorhat and Golaghat districts of upper Assam, northeast India, were selected randomly from the pool of Agaru cultivating areas based on informal knowledge which roughly represented about 30% of all Agaru growing areas in the site. A total of 135 homegardens (with a mean of 5 homegardens per site) were selected randomly and studied during 2007–2010 (Table 1). Vegetation was studied using quadrat method covering a minimum of 30% of the area in each homegarden. Random quadrats of 10 m × 10 m size were used for trees and, within the same 10 m × 10 m quadrat, one 5 m × 5 m quadrat for shrubs and two 1 m × 1 m quadrats for herbs were used in the studied homegardens. Diameter at breast height (DBH) of all the individual trees was recorded during the study at 1.37 m above ground. Plant species were identified on the basis of vernacular names, published field inventories, floras, and consulting available herbaria of the region. Herbarium specimens were collected and deposited in the Department of Forestry, North Eastern Regional Institute of Science and Technology (Deemed University), Arunachal Pradesh.

Table 1: Number of studied homegardens and their mean size and number of associated species and dominant tree associate of different studied villages.

Study sites (villages)
HG studied (number)
Mean HG area in ha (SE)
Associated species (numbers)
Dominant tree associate

Buralikson (BS)
2
0.17 ± 0.04
63
Areca catechu L.

Bhumuraguri Missing Gaon (BMG)
2
0.13 ± 0.00
62
Mesua ferrea L.

Doloigaon (DG)
2
0.11 ± 0.02
70
Areca catechu L.

Dulakhariya (DK)
2
0.16 ± 0.11
74
Areca catechu L.

Elengi Thekela Gaon (ETG)
5
0.24 ± 0.03
140
Areca catechu L.

Ganakpukhuri (GP)
5
0.16 ± 0.03
99
Areca catechu L.

Gayan Gaon (GG)
17
0.17 ± 0.02
187
Areca catechu L.

Habungia Bamun Gaon (HBG)
6
0.15 ± 0.04
117
Areca catechu L.

Hatiyekhuwa (HK)
2
0.09 ± 0.01
68
Areca catechu L.

Hensowa Chengkola Gaon (HCG)
4
0.23 ± 0.06
163
Areca catechu L.

Jalukonibari Thengal Gaon (JTG)
6
0.21 ± 0.03
138
Areca catechu L.

Junakinagar (JN)
5
0.13 ± 0.04
110
Areca catechu L.

Kabarugaon (KWG)
14
0.16 ± 0.01
168
Areca catechu L.

Kakati Gaon (KG)
4
0.15 ± 0.03
95
Areca catechu L.

Kamarbandha Bamun Gaon (KBG)
8
0.22 ± 0.02
159
Areca catechu L.

Kamarbandha Namsonia Gaon (KNG)
8
0.17 ± 0.02
135
Areca catechu L.

Khumtai (KH)
3
0.18 ± 0.02
120
Areca catechu L.

Konhar Gaon (KHG)
2
0.23 ± 0.04
67
Areca catechu L.

Natun Gaon (NG)
3
0.11 ± 0.01
91
Areca catechu L.

Naharani Maj Gaon (NMG)
2
0.17 ± 0.10
85
Areca catechu L.

Pohusora (PS)
4
0.12 ± 0.01
115
Areca catechu L.

Pulibor (PB)
8
0.21 ± 0.02
138
Areca catechu L.

Puronimati Fatagaon (PFG)
2
0.22 ± 0.01
90
Areca catechu L.

Sapani (SP)
3
0.16 ± 0.02
108
Areca catechu L.

Sialekhati (SK)
3
0.18 ± 0.02
85
Areca catechu L.

Sumoni Gaon (SMG)
9
0.21 ± 0.03
163
Areca catechu L.

Sunari Gaon (SNG)
4
0.09 ± 0.02
106
Areca catechu L.

2.3. Data Analysis

Quantitative analysis of vegetation was done following Misra [12]. Importance value index (IVI) was computed by summing up relative density, relative frequency, and relative dominance. The species richness was calculated by using the method “Margalef’s index of richness” (Dmg) [13]:

where = total number of species and = total number of individuals.

The Shannon-Wiener Diversity Index [14] was calculated from the IVI values using the formula given by Magurran [13]:

where is the proportion of the IVI of th species and the IVI of all the species (/).

Concentration of dominance was assessed by Simpson’s Index [15]:

where is the same as for the Shannon-Wiener information function.

Evenness index was calculated from Shannon-Wiener Diversity Index using the formula

where is Shannon-Wiener Diversity Index and (where = total number of species).

Sørensen’s similarity index was calculated using the formula given by Sorenson [16]:

where is the number of species common to two sites, is the total number of species in site , and is the total number of species in site .

The ratio of abundance to frequency was used to interpret the distribution pattern of the species [17]. The ratio of abundance to frequency indicates regular distribution if below 0.025, random distribution if between 0.025 and 0.05, and contagious distribution if >0.05 [18].

Statistical analysis (Standard error and -test) has been done using statistical software like MS-Excel and ORIGIN.

3. Results

3.1. Ecological Features of A. malaccensis

A. malaccensis is the most dominant tree species in twenty-seven different study sites of upper Assam contributing 10–54% of total tree density with a mean of . Density of the species varied from 429 individuals ha⁻¹ to 6,236 individuals ha⁻¹ with a mean of 1,609 individuals . Areca catechu L. is the most dominant tree associate in twenty-six different study sites, whereas Mesua ferrea L. was the most dominant tree associate in BMG, Jorhat (Table 1). Similarly, A. malaccensis is the most frequent species followed by A. catechu and Bambusa pallida L. and frequency of occurrence of A. malaccensis ranged from 93% to 100% with a mean of in different study sites. 100% frequency was recorded at most of the study sites including BS, BMG, DG, DK, ETG, HK, HCG, JTG, KWG, KNG, KG, KBG, NG, NMG, PS, PFG, SMG, and SNG. Total basal cover was the highest (1.25 cm² ha⁻¹) in NG, Jorhat, and the lowest (0.34 cm² ha⁻¹) in JN, Golaghat. Among different sites, IVI of A. malaccensis ranged between 17.94 and 72.63 with a mean of . On the other hand, abundance of the species in different study sites ranged from 4 to 62 with a mean of and it was the highest in NMG, Golaghat, and the lowest in KBG, Golaghat. Distribution of A. malaccensis is found contagious in all twenty-six study sites on the basis of abundance to frequency ratio except in KBG, Golaghat, where its distribution is random with 0.04 abundance to frequency ratio (Table 2).

Table 2: Community characteristics of different study sites of upper Assam, northeast India.

Study sites
Number of families
Number of genera
Species richness
Species richness index
Density

(individuals ha⁻¹)
Basal area

(m²ha⁻¹)
Diversity

(Shannon’s )
CD
Evenness index

BS
39
57
64
4.27
4,410
1.08
3.01
0.06
0.91

BMG
39
54
63
5.16
1,400
0.78
2.89
0.09
0.88

DG
43
63
71
3.53
3,100
0.65
2.52
0.12
0.84

DK
41
64
75
4.13
8,000
1.25
2.97
0.07
0.88

ETG
64
113
141
8.22
3,625
2.48
3.37
0.07
0.82

GP
52
85
100
7.72
3,197
1.74
3.44
0.05
0.86

GG
73
150
188
9.49
3,332
2.11
3.58
0.06
0.82

HBG
53
99
118
7.78
3,239
2.14
3.41
0.05
0.86

HK
44
63
69
4.15
6,100
0.76
2.94
0.07
0.91

HCG
67
136
164
8.30
5,341
3.09
3.56
0.05
0.86

JTG
67
122
139
6.86
7,947
2.23
3.37
0.07
0.84

JN
52
96
111
9.39
2,384
0.99
3.62
0.05
0.87

KWG
71
141
169
10.54
4,370
2.29
3.66
0.06
0.82

KG
53
83
96
6.20
3,710
0.93
3.22
0.06
0.86

KBG
64
135
160
7.69
4,133
2.58
3.78
0.03
0.93

KNG
60
116
136
7.60
3,531
3.81
3.10
0.10
0.77

KH
52
103
121
6.47
10,381
1.63
3.26
0.08
0.84

KHG
38
58
68
4.58
4,043
0.59
3.11
0.06
0.92

NG
52
82
92
5.49
4,455
0.54
3.21
0.05
0.90

NMG
52
78
86
5.21
13,418
0.99
3.22
0.07
0.88

PS
58
95
116
5.27
6,200
1.05
3.10
0.08
0.86

PB
67
119
139
9.23
2,731
2.19
3.50
0.07
0.83

PFG
49
82
91
6.10
3,885
1.79
3.27
0.06
0.89

SP
63
97
109
5.62
4,033
2.37
3.07
0.07
0.85

SK
52
79
86
7.14
2,380
0.71
3.28
0.06
0.86

SMG
65
132
164
7.77
5,205
4.40
3.29
0.07
0.79

SNG
59
94
107
5.47
5,577
0.78
3.22
0.06
0.89

3.2. Floristic Composition of Study Sites

A total of 323 plant species belonging to 241 genera under 95 families consisting of 106 (33%) herbs, 61 (19%) shrubs, and 156 (48%) trees were recorded from twenty-seven study sites of upper Assam (Table 5). Although the number of documented trees was higher than that of herbs and shrubs, differences were not statistically significant. Overall data showed that family Euphorbiaceae had the highest number of species (15) followed by Moraceae (13) and Poaceae (12). Species richness was very high at all study sites ranging from 63 to 188 species with a mean of , but the highest richness was recorded from GG, Jorhat, and the lowest from BMG, Jorhat (Table 3). A high variability in density of plant species was also noticed in different study sites. Tree density was the highest in NMG, Golaghat (13,418 individuals ha⁻¹), and the lowest in BMG, Jorhat (1,400 individuals ha⁻¹). On the other hand, basal area of tree species was the highest in SMG, Golaghat (4.40 m² ha⁻¹), and the lowest in NG, Jorhat (0.54 m² ha⁻¹).

Table 3: Ecological parameters of different populations of A. malaccensis (>3.18 cm DBH).

Study sites
Frequency (%)
Density (individuals ha⁻¹)
TBC (cm²ha⁻¹)
Abundance
IVI
Density share (%)
ratio

BS
100
1,140
0.63
11
39.26
25.85
0.11

BMG
100
709
0.64
7
72.63
50.65
0.07

DG
100
1,686
0.65
17
72.45
54.38
0.17

DK
100
3,273
0.93
33
59.12
40.91
0.33

ETG
100
1,792
0.53
18
66.46
49.43
0.18

GP
93
647
0.48
7
34.57
20.23
0.07

GG
97
1,261
0.77
13
55.71
37.85
0.13

HBG
96
896
0.50
9
42.42
27.67
0.10

HK
100
1,700
0.57
17
37.19
27.87
0.17

HCG
100
1,972
0.69
20
50.45
36.92
0.20

JTG
100
1,700
0.57
17
35.07
21.39
0.17

JN
94
858
0.34
9
50.56
35.99
0.10

KWG
100
1,563
0.69
16
52.26
35.77
0.16

KNG
100
1,793
0.70
18
68.41
50.79
0.18

KG
100
965
0.75
10
42.44
26.01
0.10

KBG
100
429
0.64
4
17.94
10.37
0.04

KHG
93
1,121
0.77
12
43.50
27.74
0.13

KH
94
1,756
0.68
19
30.05
16.92
0.20

NG
100
927
1.25
9
35.22
20.82
0.09

NMG
100
6,236
0.40
62
58.46
46.48
0.62

PS
100
3,080
0.61
31
63.78
49.68
0.31

PB
96
1,275
0.72
13
65.47
46.69
0.14

PFG
100
1,254
0.69
13
46.64
32.28
0.13

SP
93
1,467
1.08
16
50.54
36.36
0.17

SK
95
905
0.42
10
55.42
38.03
0.10

SMG
100
1,425
0.78
14
43.02
27.08
0.14

SNG
100
1,623
0.68
16
43.66
29.10
0.16

Peak richness index of tree species of 10.54 was recorded in KWG, Golaghat, whereas it was the lowest in DG, Jorhat (3.53). Concentration of dominance (Simpson’s Index) and diversity (Shannon-Wiener Diversity Index) of tree species were showing reverse trend in study sites. Concentration of dominance (Simpson’s Index) of tree species was the highest in DG, Jorhat (0.12), and the lowest in KBG, Golaghat (0.03); on the other hand, the highest diversity of tree species (Shannon-Wiener Diversity Index) was found in KBG, Golaghat (3.78,) and it was the lowest in DG, Jorhat (2.52). However, species evenness index of tree species ranged from 0.77 to 0.93 with a mean of and it was peak in KBG, Golaghat, and the lowest in KNG, Golaghat. Sørensen’s similarity indices showed a high degree of similarity with a range from 34.25% to 75.38% among different study sites (Table 4).

Table 4: Sørensen’s similarity index (%) for different study sites of upper Assam, northeast India.

BS
BMG
DG
DK
ETG
GP
GG
HBG
HK
HCG
JTG
JN
KWG
KNG
KG
KBG
KHG
KH
NG
NMG
PS
PB
PFG
SP
SK
SMG

BS
0.00

BMG
47.24
0.00

DG
56.3
49.25
0.00

DK
41.73
34.78
49.32
0.00

ETG
47.80
46.08
53.77
48.15
0.00

GP
48.78
49.08
52.63
46.86
57.26
0.00

GG
43.65
49.40
49.42
45.63
60.79
75.06
0.00

HBG
45.05
34.25
48.68
51.81
61.78
83.87
54.90
0.00

HK
52.63
45.45
54.29
45.83
51.43
89.12
44.36
48.13
0.00

HCG
44.74
38.77
43.40
46.03
62.95
73.11
60.80
65.25
46.35
0.00

JTG
51.23
44.55
51.43
43.93
63.57
69.10
67.28
56.03
53.85
66.01
0.00

JN
50.29
48.28
53.85
47.31
60.32
78.44
55.52
49.78
53.33
54.55
64.80
0.00

KWG
46.35
44.83
50.00
41.80
69.68
60.00
66.67
57.14
47.90
62.46
66.23
70.00
0.00

KNG
51.00
44.22
52.17
50.24
64.98
77.31
60.49
66.14
51.71
62.67
65.45
63.97
71.48
0.00

KG
47.50
55.35
57.49
46.78
59.07
79.20
61.97
52.34
50.91
53.08
55.32
62.80
62.64
60.34
0.00

KBG
51.79
41.26
49.35
43.40
67.11
64.68
63.79
57.55
54.15
67.90
71.57
61.25
68.09
69.59
57.03
0.00

KHG
51.52
36.64
74.82
46.15
46.89
98.43
46.09
46.24
45.26
37.93
46.38
45.81
47.26
48.04
51.22
40.35
0.00

KH
46.49
43.478
56.25
51.02
64.12
79.57
58.25
61.09
61.05
61.75
57.69
60.34
61.38
62.26
56.22
61.92
49.74
0.00

NG
55.13
54.19
61.35
47.90
57.51
83.30
54.29
54.29
54.66
52.34
58.01
59.11
57.47
58.77
59.57
53.97
51.25
55.40
0.00

NMG
52.00
41.61
48.41
45.96
47.58
96.61
47.45
51.96
56.77
50.40
51.56
56.85
55.69
50.45
54.95
53.66
44.16
56.04
51.69
0.00

PS
52.22
39.11
52.41
48.17
60.70
79.35
56.58
58.12
51.89
58.57
61.96
57.27
58.95
58.73
56.60
61.59
48.91
58.23
51.92
47.52
0.00

PB
49.26
43.56
51.43
44.86
62.86
71.37
61.77
63.81
51.92
66.01
69.78
68.80
70.13
68.36
62.98
66.89
45.41
61.54
55.41
56.89
61.18
0.00

PFG
54.19
45.45
51.85
48.19
58.62
82.21
54.48
49.76
53.75
47.06
60.87
53.47
58.46
56.39
58.82
55.78
57.86
53.77
57.92
53.11
57.97
55.65
0.00

SP
49.71
52.33
57.78
44.57
61.60
72.35
62.63
52.86
55.06
56.41
61.29
58.18
61.15
59.59
67.32
62.45
49.72
56.52
61.69
55.38
55.11
61.29
55.00
0.00

SK
50.67
46.98
48.41
47.20
50.22
94.00
48.91
47.06
55.48
53.60
51.56
65.99
55.69
53.15
58.24
55.28
40.26
50.24
53.93
52.33
49.50
59.56
49.72
58.46
0.00

SMG
47.37
46.70
50.21
50.21
67.54
74.34
65.91
62.41
50.64
40.24
66.67
61.09
65.47
66.67
53.85
68.52
44.83
67.37
57.81
54.40
61.43
64.69
54.12
58.61
50.40
0.00

SNG
53.80
50.59
59.55
41.76
62.10
67.25
56.27
56.89
59.09
57.56
61.79
62.39
63.77
61.73
64.04
64.42
49.14
57.02
75.38
53.89
55.61
61.79
59.60
66.67
53.89
61.25

Table 5: Density (individuals ha⁻¹), frequency (%), abundance, and IVI of tree (>3.18 cm DBH), shrub, and herb species in studied homegardens of upper Assam, northeast India.

Species
Family
Density (individuals ha⁻¹)
Frequency (%)
Abundance
IVI

Trees

Acacia auriculiformis Cunn. ex Benth.
Mimosaceae
1.06
0.66
2
1.76

Adenanthera pavonina L.
Mimosaceae
2.38
2.11
1
0.94

Aegle marmelos Corr.
Rutaceae
2.64
2.51
1
1.00

Ailanthus grandis Prain
Simaroubaceae
0.13
0.13
1
0.87

Albizia lebbeck (L.) Benth.
Mimosaceae
2.11
1.32
2
2.30

Albizia lucida (Roxb.) Benth.
Mimosaceae
7.53
5.28
1
1.68

Albizia procera (Roxb.) Benth.
Mimosaceae
0.66
0.66
1
0.68

Alstonia scholaris (L.) R. Br.
Apocynaceae
15.85
11.89
1
2.90

Amoora wallichii King
Meliaceae
0.66
0.53
1
0.42

Anacardium occidentale L.
Anacardiaceae
0.26
0.26
1
0.71

Annona reticulata L.
Annonaceae
1.06
1.06
1
0.39

Anthocephalus chinensis (Lam.) Rich. ex Walp.
Rubiaceae
5.81
4.49
1
2.22

Antidesma ghaesembilla Gaert.
Euphorbiaceae
0.40
0.40
1
0.21

Aquilaria malaccensis Lam.
Thymelaeaceae
1442.67
98.02
15
49.50

Arabongali*

0.26
0.26
1
0.21

Araucaria heterophylla (Salisb.) Franco
Araucariaceae
0.53
0.53
1
0.32

Areca catechu L.
Arecaceae
554.29
74.37
7
24.94

Artocarpus chaplasha Roxb.
Moraceae
2.25
1.59
1
1.46

Artocarpus heterophyllus Lam.
Moraceae
34.87
24.57
1
5.49

Artocarpus lakoocha Roxb.
Moraceae
3.04
2.77
1
1.83

Averrhoa carambola L.
Averrhoaceae
4.49
4.23
1
1.19

Azadirachta indica Juss.
Meliaceae
1.19
1.19
1
0.43

Baccaurea sapida (Roxb.) Mull. Arg.
Euphorbiaceae
1.32
1.19
1
0.36

Bambusa balcooa Roxb.
Poaceae
214.93
3.04
71
5.53

Bambusa nutans G. C. Wall. ex Munro
Poaceae
2.25
0.13
17
0.07

Bambusa pallida Munro.
Poaceae
1157.60
11.23
103
28.96

Bambusa tulda Roxb.
Poaceae
50.99
0.53
97
1.28

Bauhinia purpurea L.
Caesalpiniaceae
0.26
0.26
1
0.46

Beilschmiedia brandisii Hook. f.
Lauraceae
1.45
0.79
2
0.48

Bixa orellana L.
Bixaceae
2.38
1.72
1
0.54

Bombax ceiba L.
Malvaceae
3.83
3.43
1
1.75

Borassus flabellifer L.
Arecaceae
0.13
0.13
1
1.74

Bridelia retusa (L.) A. Juss.
Euphorbiaceae
0.66
0.40
2
0.66

Butea monosperma (Lam.) Taubert
Papilionaceae
0.40
0.26
2
0.95

Callistemon lanceolatus D.C.
Myrtaceae
0.53
0.40
1
0.29

Canarium strictum Roxb.
Burseraceae
0.53
0.53
1
1.07

Carallia lucida Roxb. ex Kurz.
Rhizophoraceae
1.72
1.59
1
0.52

Carica papaya L.
Caricaceae
34.48
18.63
2
3.95

Caryota urens L.
Arecaceae
1.98
1.59
1
1.13

Cassia fistula L.
Caesalpiniaceae
12.15
7.79
2
2.04

Cassia siamea Lam.
Caesalpiniaceae
1.85
1.72
1
0.86

Castanopsis indica (Roxb. ex Lindl.) A. D.C.
Fagaceae
1.19
0.66
2
0.44

Chukrasia tabularis Juss.
Meliaceae
1.06
0.79
1
0.92

Cinnamomum glanduliferum (Wall.) Meisn.
Lauraceae
0.26
0.26
1
1.10

Cinnamomum tamala (Buch.-Ham.) Nees and Eberm.
Lauraceae
5.28
4.36
1
1.05

Citrus limon (L.) Burm.f.
Rutaceae
7.79
4.76
2
0.97

Citrus maxima (Merr.)
Rutaceae
10.44
9.25
1
1.91

Citrus medica L.
Rutaceae
0.92
0.53
2
0.13

Citrus reticulata Blanco.
Rutaceae
7.13
4.76
2
0.97

Citrus sinensis (L.) Osbeck
Rutaceae
1.06
0.66
2
0.18

Citrus sp.
Rutaceae
2.38
1.85
1
0.38

Cocos nucifera L.
Arecaceae
25.76
17.83
1
4.38

Cordia grandis Roxb.
Boraginaceae
2.64
2.11
1
0.82

Crataeva nurvala Ham.
Capparidaceae
1.32
1.19
1
0.53

Dalhousiea bracteata (Roxb.) Baker
Papilionaceae
0.13
0.13
1
0.30

Delonix regia (Boj. ex Hook.) Raf.
Caesalpinaceae
2.38
1.85
1
0.87

Dillenia indica L.
Dilleniaceae
0.66
0.66
1
3.00

Diospyros embryopteris Pers.
Ebenaceae
0.53
0.40
1
1.24

Dysoxylum binectariferum (Roxb.) Hook. f. ex Bedd.
Meliaceae
2.64
1.98
1
1.08

Ehretia acuminata R.Br.
Boraginaceae
1.06
1.06
1
0.71

Elaeocarpus floribundus Blume.
Elaeocarpaceae
5.55
5.02
1
1.56

Elaeocarpus ganitrus Roxb.
Elaeocarpaceae
0.13
0.13
1
1.29

Erythrina stricta Roxb.
Papilionaceae
2.51
1.59
2
0.67

Eucalyptus citriodora Hook.
Myrtaceae
0.79
0.79
1
0.95

Eugenia fruticosa Roxb.
Myrtaceae
1.59
1.32
1
0.57

Eugenia jambolana Lam.
Myrtaceae
5.55
4.49
1
1.39

Eugenia jambolana Lam. var. caryophyllifolia Duthie.
Myrtaceae
0.40
0.40
1
0.63

Eugenia jambos L.
Myrtaceae
3.04
2.91
1
0.73

Evodia meliaefolia Benth.
Rutaceae
2.77
2.38
1
1.13

Ficus benghalensis L.
Moraceae
0.26
0.26
1
9.66

Ficus cyrtophylla
Moraceae
0.53
0.13
1
0.03

Ficus fistulosa Reinw. ex Blume
Moraceae
0.53
0.53
2
9.66

Ficus hirta Vahl.
Moraceae
1.06
0.13
1
0.04

Ficus hispida L.
Moraceae
5.28
3.96
25
0.89

Ficus racemosa L.
Moraceae
0.40
0.40
3
0.39

Ficus religiosa L.
Moraceae
0.53
0.53
4
6.56

Garcinia lanceaefolia Roxb.
Clusiaceae
0.26
0.26
1
0.43

Garcinia morella (Gaertn.) Desr.
Clusiaceae
1.45
1.06
7
0.44

Garcinia paniculata Roxb.
Clusiaceae
0.26
0.26
2
0.2

Garcinia pedunculata Roxb. Engl.
Clusiaceae
0.79
0.79
6
0.96

Garcinia xanthochymus Hook. f. ex Anderson Engl.
Clusiaceae
0.40
0.40
3
0.39

Gmelina arborea Roxb.
Verbenaceae
10.30
6.87
36
2.02

Grevillea robusta Cunn. ex R.Br.
Proteaceae
1.72
1.32
8
1.37

Heteropanax fragrans (Roxb.) Seem.
Araliaceae
4.76
3.04
11
1.16

Ilex umbellulata (Wall.) Loes.
Aquifoliaceae
1.32
1.19
8
0.38

Lagerstroemia flos reginae Retz.
Lythraceae
6.08
4.89
24
1.53

Litchi chinensis Sonn.
Sapindaceae
6.34
5.55
36
1.43

Litsea elongata Wall.
Lauraceae
0.79
0.53
3
0.32

Litsea monopetala (Roxb.) Pers.
Lauraceae
10.30
8.19
45
2.01

Litsea nitida Hook. f.
Lauraceae
12.29
8.06
37
1.86

Litsea sebifera Pers.
Lauraceae
1.19
1.19
7
0.47

Livistona jenkinsiana Griff.
Arecaceae
1.72
1.45
7
1.2

Macaranga peltata (Roxb.) Mueller
Euphorbiaceae
0.13
0.13
1
0.22

Magnolia sphenocarpa Roxb.
Magnoliaceae
4.76
3.17
16
0.99

Mallotus philippinensis Muell. Arg.
Euphorbiaceae
3.57
3.43
24
0.84

Mangifera indica L.
Anacardiaceae
62.48
35.80
115
7.79

Manilkara zapota (L.) van Royen
Sapotaceae
0.13
0.13
1
1.07

Melia azedarach L.
Meliaceae
9.38
7.27
37
1.61

Mesua ferrea L.
Clusiaceae
5.15
3.57
24
1.01

Michelia champaca L.
Magnoliaceae
2.25
1.19
6
0.75

Mimusops elengi L.
Sapotaceae
0.66
0.66
5
1.42

Moringa oleifera Lam.
Moringaceae
4.62
4.10
29
1.15

Morus alba L.
Moraceae
2.25
1.32
9
0.56

Morus laevigata Wall.
Moraceae
0.13
0.13
1
0.2

Murraya koenigii (L.) Sprengel.
Rutaceae
2.38
1.85
12
0.49

Murraya paniculata (L.) Jack
Rutaceae
0.13
0.13
1
0.19

Musa acuminata Colla.
Musaceae
64.33
12.42
57
3.64

Musa balbisiana Colla.
Musaceae
137.38
24.83
92
7.4

Musa calosperma F. Muell.
Musaceae
72.26
14.40
62
4.14

Musa paradisiaca L.
Musaceae
0.53
0.26
2
0.19

Musa sp.
Musaceae
12.42
3.04
17
0.98

Myrica esculenta Buch.-Ham. ex D. Don
Myricaceae
2.64
1.98
12
0.7

Oroxylum indicum (L.) Kurz.
Bignoniaceae
5.02
4.36
24
1.13

Pachylarnax pleiocarpa Dandy
Magnoliaceae
0.92
0.79
5
0.96

Persea bombycina (King ex Hook. f.) Kost.
Lauraceae
3.04
2.25
15
0.86

Phoebe goalparensis Hutch.
Lauraceae
0.13
0.13
1
0.19

Phoenix dactylifera L.
Arecaceae
0.53
0.40
2
1.04

Phyllanthus acidus (L.) Skeels.
Phyllanthaceae
1.06
1.06
8
0.35

Phyllanthus emblica L.
Phyllanthaceae
5.15
5.02
31
1.26

Plumeria rubra L.
Apocynaceae
0.26
0.13
1
0.24

Polyalthia longifolia (Sonn.) Thw.
Annonaceae
6.87
2.64
14
0.76

Pongamia pinnata (L.) Pierre.
Papilionaceae
1.72
1.45
10
0.71

Premna bengalensis Cl.
Verbenaceae
5.55
4.49
25
1.14

Prunus cerasifera Ehrh.
Rosaceae
1.59
1.32
8
0.46

Prunus jenkinsii Hook. f. and Thoms.
Rosaceae
0.53
0.53
3
0.21

Prunus persica (L.) Batsch.
Rosaceae
0.92
0.92
6
0.31

Psidium gujava L.
Myrtaceae
16.64
12.42
63
2.5

Pyrus communis L.
Rosaceae
1.06
0.79
4
0.26

Salix tetrasperma Roxb.
Salicaceae
4.49
2.11
10
0.84

Samanea saman (Jacq.) Merr.
Mimosaceae
0.26
0.26
2
4.03

Sapindus mukorossi Gaertn.
Sapindaceae
1.85
1.72
10
0.64

Sapium baccatum Roxb.
Euphorbiaceae
1.32
1.06
4
0.63

Sapium eugeniaefolium Ham.
Euphorbiaceae
0.53
0.53
4
0.53

Schimawallichii (DC.) Korth.
Theaceae
4.76
2.91
16
1.12

Shorea robusta Gaertn. f.
Dipterocarpaceae
0.13
0.13
1
2.92

Spondias mangifera Wild.
Anacardiaceae
1.19
0.92
7
0.54

Stereospermum chelonoides DC.
Sterculiaceae
0.92
0.66
5
0.38

Streblus asper Lour.
Moraceae
3.70
2.11
12
0.73

Symplocos grandiflora Wall.
Symplocaceae
0.13
0.13
1
0.22

Talauma hodgsonii Hook. f. and Thomson
Magnoliaceae
0.13
0.13
1
4.65

Talauma rabaniana Hk.ef. and Th.
Magnoliaceae
0.40
0.40
2
2.06

Tamarindus indica L.
Caesalpiniaceae
0.26
0.26
2
0.43

Tectona grandis L.
Verbenaceae
25.36
9.78
40
2.83

Terminalia arjuna (Roxb. ex DC.) Wight and Arn.
Combretaceae
0.26
0.26
2
0.57

Terminalia bellirica (Gaertn.) Roxb.
Combretaceae
0.13
0.13
1
0.16

Terminalia catappa L.
Combretaceae
0.40
0.40
3
0.89

Terminalia chebula Retz.
Combretaceae
14.66
12.42
64
2.95

Terminalia myriocarpa Van Heurck and Muell. Arg.
Combretaceae
0.26
0.26
2
0.39

Toona ciliata Roem.
Meliaceae
13.87
10.30
45
2.88

Tricalysia singularis (Korth.) K. Schum.
Rubiaceae
0.66
0.40
3
0.66

Vernonia travancorica J. Hk.
Asteraceae
0.13
0.13
1
0.04

Vitex negundo L.
Verbenaceae
0.79
0.79
6
0.4

Walsura robusta Roxb.
Meliaceae
0.40
0.40
3
0.38

Zanthoxylum rhetsa (Roxb.) DC.
Rutaceae
1.19
1.06
8
0.71

Ziziphus mauritiana Lam.
Rhamnaceae
4.62
4.36
27
1.26

Ziziphus sp.
Rhamnaceae
0.13
0.13
1
0.42

Shrubs

Acacia farnesiana (L.) Willd.
Mimosaceae
7.40
1.72
1.08
0.41

Adhatoda vasica Nees
Acanthaceae
79.26
4.10
4.84
1.52

Bisalyakarani*

5.28
0.13
10.00
0.07

Bougainvillea spectabilis Wild.
Nyctaginaceae
5.81
1.32
1.10
0.32

Caesalpinia pulcherrima L.
Caesalpiniaceae
2.11
0.53
1.00
0.13

Cajanus cajan (L.) Millsp.
Papilionaceae
28.01
1.72
4.08
0.59

Calamus tenuis Roxb.
Arecaceae
43.33
2.38
4.56
0.86

Callicarpa arborea Roxb.
Verbenaceae
11.10
0.79
3.50
0.26

Calotropis procera (Ait.) Ait. f.
Asclepiadaceae
4.76
0.92
1.29
0.23

Camellia sinensis (L.) O. Kuntze
Theaceae
1958.78
21.14
23.17
21.23

Capsicum annum L.
Solanaceae
67.11
5.42
3.10
1.68

Capsicum annum L. var. longum
Solanaceae
86.13
6.74
3.20
2.12

Capsicum chinense Jacq.
Solanaceae
61.29
6.21
2.47
1.80

Cassia alata L.
Caesalpinaceae
11.10
0.92
3.00
0.28

Cassia sophera L.
Caesalpinaceae
5.28
0.79
1.67
0.21

Cassia tora L.
Caesalpinaceae
7.93
0.53
3.75
0.18

Chromolaena odorata (L.) King and H.E. Robins.
Asteraceae
528.40
18.23
7.25
8.28

Clerodendrum colebrookianum Wall.
Verbenaceae
33.82
2.51
3.37
0.80

Clerodendrum japonicum (Thunb.) Sweet
Verbenaceae
22.72
1.85
3.07
0.57

Clerodendrum viscosum Vent.
Verbenaceae
984.94
29.59
8.32
14.54

Codiaeum variegatum (L.) Juss.
Euphorbiaceae
56.01
7.13
1.96
1.94

Coffea benghalensis Roxb. ex Schult.
Rubiaceae
18.49
1.59
2.92
0.48

Dracaena steudneri Engl.
Dracaenaceae
5.28
0.79
1.67
0.21

Euonymus japonicus Thunb.
Celastraceae
144.25
6.87
5.25
2.65

Euphorbia neriifolia L.
Euphorbiaceae
8.45
1.72
1.23
0.42

Flacourtia cataphracta Roxb. ex Willd.
Flacourtiaceae
11.10
2.38
1.17
0.58

Flemingia strobilifera (L.) R. Br.
Papilionaceae
22.19
2.38
2.33
0.68

Gardenia jasminoides Ellis.
Rubiaceae
41.22
5.94
1.73
1.57

Glochidion arborescens Bl.
Euphorbiaceae
1.06
0.26
1.00
0.06

Gossypium arboreum L.
Malvaceae
25.36
4.62
1.37
1.16

Hibiscus mutabilis L.
Malvaceae
4.23
0.92
1.14
0.23

Hibiscus rosa-sinensis L.
Malvaceae
76.09
9.25
2.06
2.54

Hibiscus sabdariffa L.
Malvaceae
57.07
3.30
4.32
1.17

Ixora javanica (Blume) DC.
Rubiaceae
22.72
2.64
2.15
0.74

Jasminum officinale L.
Oleaceae
6.87
1.45
1.18
0.36

Jatropha gossypiifolia L.
Euphorbiaceae
5.28
0.79
1.67
0.21

Justicia gendarussa Blanco.
Acanthaceae
56.54
2.11
6.69
0.92

Lawsonia inermis L.
Lawsoniaceae
10.57
2.25
1.18
0.55

Leea indica (Burm. f.) Merr.
Leeaceae
11.62
1.45
2.00
0.40

Malvaviscus arboreus Cav. var. drummondii (Torr. and Gray) Schery.
Malvaceae
14.27
1.98
1.80
0.53

Melastoma normale D. Don.
Melastomataceae
70.81
4.49
3.94
1.53

Mussaenda frondosa L.
Rubiaceae
28.01
3.57
1.96
0.97

Nerium indicum Mill.
Apocynaceae
11.10
2.11
1.31
0.53

Nyctanthes arbor-tristis L.
Oleaceae
26.95
5.68
1.19
1.39

Ocimum gratissimum L.
Lamiaceae
8.45
1.06
2.00
0.29

Ocimum sanctum L.
Lamiaceae
67.64
6.21
2.72
1.85

Phlogacanthus thyrsiflorus (Roxb.) Nees
Acanthaceae
38.04
2.11
4.50
0.76

Pogostemon benghalensis (Burm. f.) O. Kuntze
Lamiaceae
20.61
0.66
7.80
0.31

Punica granatum L.
Punicaceae
12.15
2.64
1.15
0.64

Ravenala madagascariensis Sonnerat.
Strelitziaceae
6.87
0.40
4.33
0.14

Ricinus communis L.
Euphorbiaceae
172.79
5.55
7.79
2.62

Rosa alba L.
Rosaceae
33.29
3.17
2.63
0.93

Saccharum officinarum L.
Poaceae
239.37
3.70
16.18
2.82

Sida cordifolia L.
Malvaceae
15.85
0.53
7.50
0.24

Solanum indicum L.
Solanaceae
5.28
0.79
1.67
0.21

Solanum melongena L.
Solanaceae
93.00
6.08
3.83
2.04

Solanum subtrucatum
Solanaceae
0.53
0.13
1.00
0.03

Solanum torvum Swartz.
Solanaceae
11.10
1.59
1.75
0.42

Tabernaemontana divaricata G. Don.
Apocynaceae
63.94
7.27
2.20
2.03

Thuja occidentalis L.
Cupressaceae
3.17
0.66
1.20
0.16

Urena lobata L.
Malvaceae
172.79
6.47
6.67
2.81

Herb

Abelmoschus esculentus (L.) Moench
Malvaceae
244
0.40
6.17
0.11

Achyranthes aspera L.
Amaranthaceae
18032
26.02
6.93
7.83

Acorus calamus L.
Araceae
185
0.13
14.00
0.06

Ageratum conyzoides L.
Asteraceae
22120
37.52
5.90
10.48

Alocasia odora (Lindl.) Koch.
Araceae
2583
7.46
3.46
1.71

Alpinia allughas L.
Zingiberaceae
20
0.07
3.00
0.01

Alternanthera sessilis (L.) R. Br. ex DC.
Amaranthaceae
5713
10.17
5.62
2.78

Amaranthusblitum L. var. oleracea Hook. f.
Amaranthaceae
535
0.99
5.40
0.27

Amaranthus caudatus L.
Amaranthaceae
145
0.73
2.00
0.14

Amaranthus spinosus L.
Amaranthaceae
264
0.59
4.44
0.15

Amaranthus viridis L.
Amaranthaceae
7345
9.58
7.67
3.03

Amorphophallus campanulatus (Roxb.) Bl. ex Decne.
Araceae
304
0.79
3.83
0.19

Ananas comosus (L.) Merr.
Bromeliaceae
7999
9.78
8.18
3.20

Asparagus racemosus Willd.
Asparagaceae
26
0.13
2.00
0.03

Atriplex hortensis L.
Chenopodiaceae
277
0.46
6.00
0.13

Axonopus sp.
Poaceae
60885
34.28
17.76
18.07

Bacopa monnieri (L.) Pennell
Scrophulariaceae
383
0.40
9.67
0.14

Benincasa hispida (Thunb) Cogn.
Cucurbitaceae
178
0.92
1.93
0.18

Borreria articularis (L. f.) F. N. Will.
Rubiaceae
18336
23.91
7.67
7.57

Borreria hispida (L.) K. Schum.
Rubiaceae
2272
4.62
4.91
1.20

Brassica juncea (L.) Czern. and Cross. var. cuneifolia (Roxb.) Kitam.
Brassicaceae
2067
1.65
12.52
0.69

Brassica oleracea L. var. botrytis L.
Brassicaceae
515
0.59
8.67
0.20

Brassica oleracea L. var. capitata L.
Brassicaceae
608
0.73
8.36
0.24

Brassica oleracea L. var. gongylodes L.
Brassicaceae
872
1.12
7.76
0.36

Bryophyllum pinnatum Lam.
Crassulaceae
1849
4.43
4.18
1.08

Cannabis sativa L.
Cannabaceae
661
1.52
4.35
0.38

Carex sp.
Cyperaceae
211
0.46
4.57
0.12

Catharanthus roseus L.
Apocynaceae
211
0.79
2.67
0.17

Celosia sp.
Amaranthaceae
159
0.53
3.00
0.12

Centella asiatica (L.) Urban
Apiaceae
7325
13.80
5.31
3.69

Chenopodium album L.
Chenopodiaceae
251
0.86
2.92
0.19

Chrysopogon aciculatus (Retz.) Trin.
Poaceae
6532
3.76
17.35
1.95

Cleome viscosa L.
Capparaceae
192
0.79
2.42
0.16

Clitoria ternatea L.
Papilionaceae
46
0.40
1.17
0.07

Coccinia cordifolia (L.) Cogn.
Cucurbitaceae
185
0.92
2.00
0.18

Coleus sp.
Lamiaceae
159
0.33
4.80
0.08

Colocasia esculenta (L.) Schott
Araceae
13349
20.94
6.38
6.06

Commelina benghalensis L.
Commelinaceae
4505
8.72
5.17
2.30

Coriandrum sativum L.
Apiaceae
1572
0.59
26.44
0.42

Costus speciosus (Koen. ex Retz.) Smith
Costaceae
159
0.66
2.40
0.14

Crassocephalum crepidioides (Benth.) Moore.
Asteraceae
462
1.25
3.68
0.29

Cucumis sativus L.
Cucurbitaceae
159
0.46
3.43
0.11

Cucurbita pepo L.
Cucurbitaceae
297
1.32
2.25
0.27

Cuphea carthagenensis (Jacq.) JF Macbr.
Lythraceae
1955
3.83
5.10
1.01

Curcuma longa L.
Zingiberaceae
4914
3.43
14.31
1.56

Cynodon dactylon (L.) Pers.
Poaceae
20086
19.29
10.41
7.21

Cyperus brevifolius (Rottb.) Endl. ex Hassk.
Cyperaceae
3554
6.08
5.85
1.69

Cyperus rotundus L.
Cyperaceae
14650
20.34
7.20
6.24

Cyperus sp.
Cyperaceae
6968
13.41
5.20
3.55

Daucus carota L. var. sativa DC.
Apiaceae
1770
0.99
17.87
0.52

Desmodium elegans DC.
Papilionaceae
26
0.13
2.00
0.03

Dioscorea alata L.
Dioscoreaceae
476
2.11
2.25
0.43

Dioscorea deltoidea Wall.
Dioscoreaceae
40
0.26
1.50
0.05

Diplazium esculentum (Retz.) Sw.
Athyriaceae
1830
4.76
3.85
1.13

Dolichos lablab L.
Papilionaceae
132
0.79
1.67
0.15

Drymaria cordata (L.) Wild ex Roemer and Schultes
Caryophyllaceae
7919
9.51
8.33
3.14

Dryopteris sp.
Dryopteridaceae
12450
18.23
6.83
5.45

Eclipta prostrata L.
Asteraceae
139
0.86
1.62
0.16

Eryngium foetidum L.
Apiaceae
489
1.06
4.63
0.27

Houttuynia cordata Thunb.
Saururaceae
1836
1.65
11.12
0.64

Impatiens balsamina L.
Balsaminaceae
1440
2.51
5.74
0.69

Imperata cylindrica (L.) Raeusch.
Poaceae
264
0.07
40.00
0.07

Justicia simplex D. Don.
Acanthaceae
8303
16.91
4.91
4.38

Lagenaria siceraria (Mol.) Standl.
Cucurbitaceae
244
1.25
1.95
0.25

Leucas aspera (Willd.) Spreng.
Lamiaceae
2715
6.74
4.03
1.62

Longbon*
Rubiaceae
1030
2.44
4.22
0.60

Luffaacutangula (L.) Roxb.
Cucurbitaceae
462
1.45
3.18
0.32

Luffa cylindrica (L.) Roem.
Cucurbitaceae
304
1.32
2.30
0.27

Lycopersicon esculentum Mill.
Solanaceae
601
1.65
3.64
0.38

Mentha viridis L.
Lamiaceae
416
0.53
7.88
0.17

Mikania micrantha Kunth ex H.B.K.
Asteraceae
6559
15.92
4.12
3.86

Momordica charantia L.
Cucurbitaceae
79
0.33
2.40
0.07

Momordica dioica Roxb. ex Willd
Cucurbitaceae
410
1.45
2.82
0.31

Mimosa pudica L.
Mimosaceae
244
0.99
2.47
0.21

Mirabilis jalapa L.
Nyctaginaceae
462
1.06
4.38
0.26

Oldenlandia corymbosa L.
Rubiaceae
4287
5.75
7.46
1.79

Oplismenus sp.
Poaceae
37457
28.93
12.95
12.34

Oryza sativa L.
Poaceae
449
0.26
17.00
0.14

Oxalis corniculata L.
Oxalidaceae
4822
7.79
6.19
2.22

Oxalis debilis H.B.K. var. corymbosa (DC.) Lour.
Oxalidaceae
5588
8.39
6.66
2.48

Paederia foetida L.
Rubiaceae
198
0.46
4.29
0.11

Panicum sp.
Poaceae
38573
38.64
9.98
14.09

Passiflora foetida L.
Passifloraceae
119
0.66
1.80
0.13

Peperomia pellucida L.
Piperaceae
5033
7.79
6.46
2.27

Phyllanthus fraternus Webster
Euphorbiaceae
6420
14.73
4.36
3.64

Piper betle L.
Piperaceae
4868
12.62
3.86
2.99

Piper nigrum L.
Piperaceae
1856
5.35
3.47
1.22

Piper sylvaticum Roxb.
Piperaceae
627
0.92
6.79
0.28

Pollia sp.
Commelinaceae
165
0.33
5.00
0.09

Polygonum chinense L.
Polygonaceae
205
0.20
10.33
0.07

Polygonum hydropiper L.
Polygonaceae
1777
1.85
9.61
0.66

Polygonum microcephalum D. Don
Polygonaceae
159
0.13
12.00
0.05

Potentilla indica (Andrews) Wolf.
Rosaceae
403
0.79
5.08
0.21

Pteris sp.
Pteridaceae
1110
2.84
3.91
0.68

Raphanus sativus L.
Brassicaceae
1004
0.86
11.69
0.34

Rhynchostylis retusa (L.) Blume.
Orchidaceae
99
0.59
1.67
0.11

Scoparia dulcis L.
Scrophulariaceae
1982
4.43
4.48
1.11

Selaginella sp.
Selaginellaceae
1096
0.66
16.60
0.33

Siral*
Cucurbitaceae
13
0.07
2.00
0.01

Solanum nigrum L.
Solanaceae
178
0.92
1.93
0.18

Solanum tuberosum L.
Solanaceae
1202
0.46
26.00
0.32

Spilanthes paniculata Wall. ex DC.
Asteraceae
10416
16.64
6.26
4.78

Spinacia oleracea L.
Chenopodiaceae
852
1.25
6.79
0.37

Tagetes patula L.
Asteraceae
1466
3.76
3.89
0.89

Vigna sinensis (L.) Savi ex Hassk.
Papilionaceae
218
0.86
2.54
0.18

Zingiber officinale Roscoe
Zingiberaceae
1731
1.12
15.41
0.54

Locale name.

4. Discussion

Floristic inventory, survey, and diversity studies help us to understand the species composition and diversity status of any community [19]. A. malaccensis is one of the most dominant tree species in study sites of upper Assam representing 10–54% of the total tree density (with a mean of ) showing a trend towards monoculture. In general, monoculture has a great impact on species diversity. Introduction of rubber (Hevea brasiliensis) into homegardens resulted in a reduction of species diversity in homegardens of Kerela [20]. But this is not evident in the present study and may be due to the fact that owners tried to produce all the possible species of common household utilities in their homegarden itself.

Density of a species provides an index to competition between individuals of the species. Higher densities can cause greater competitive stresses, leading to poor growth and lower reproductive capacity. We recorded A. malaccensis with high density (429 to 6,236 individuals ha⁻¹ with a mean of 1,609 individuals ), frequency (93% to 100% with a mean of ), and abundance (4 to 62 with a mean of ). One potential explanation of higher density, frequency, and abundance could be extensive cultivation of the species in study sites because of its high commercial value. Total basal cover of trees (>3.18 cm DBH) is very low and ranged from 0.34 cm² ha⁻¹ to 1.25 cm² ha⁻¹ with a mean of 0.67 cm² , may be because of the highest density of lower diameter class individuals of A. malaccensis. Importance value index (IVI) of the species represents the ecological success of any species in a community and it gives an excellent idea about varying environmental factors [21]. It provides a complete picture of sociological structure of a species, because the frequency provides information about the dispersal of a species in an area, density gives numerical strength of the species, and dominance represents the basal area. In almost all study sites, the highest IVI is contributed by A. malaccensis which is ranged from 17.94 to 72.63 with a mean of . Dispersal limitation is an important ecological factor for controlling species distribution pattern [22]. Contagious distribution has been accepted as a characteristic pattern of plant occurrence in nature [23] and it is an indication of clusteredness. Contagious distribution of A. malaccensis is found in all study sites except in KBG, Golaghat, where its distribution is random with abundance to frequency ratio of 0.04. Contagious distribution of all the species irrespective of their habit in homegardens of northeast India is also reported by Sahoo et al. [24].

Ecological and socioeconomic factors including geographic location, climate, water availability, garden size and history, agricultural policy, market needs, food culture, and household preferences influence the species diversity of traditional homegardens [25–27]. Needs and interest of homegarden owners may also play a vital role in regulating floristic compositions of homegardens apart from edaphic, cultural, and socioeconomic factors [5]. Species richness provides an easily comprehensible expression of diversity which is affected by long term factors like community stability and evolutionary time as the heterogeneity of micro- and macroenvironments impact on the diversification of different communities [28]. Our investigation recorded 323 plant species (156 trees, 61 shrubs, and 106 herbs) indicating a high species richness of the study site. It is much higher than the earlier reports from Assam [29] as well as other parts of the world [30, 31]. This may be due to the diverse cultural practices of the region and prevailing microclimatic conditions which provide suitable growing conditions for different plant species. Constituent of high floristic diversity is perhaps the potential of homegardens to serve as repositories of genetic diversity [5]. Very high species richness at all study sites is recorded in the present study ranging from 63 to 188 species with a mean of which is much higher than the earlier report from other parts of the world [25, 32]. Although tree density (1,400 to 13,418 individuals ha⁻¹) in different study sites was much higher than the recorded tree density in homegardens of other parts of India [29, 31], the basal cover of tree species (0.54 to 4.40 m² ha⁻¹) was much lesser than earlier report from Assam [29]. This may be due to the dominance of narrow range diameter class species in the study sites of upper Assam, northeast India.

Higher species richness indices (3.53 to 10.54) and species evenness indices (0.77 to 0.93) represent the floristic richness of all the study sites of upper Assam, northeast India. Shannon-Wiener diversity index is generally high for tropical forests of Indian subcontinent and ranged from 0.81 to 4.1 [33–36]. Shannon-Wiener diversity indices ranging from 2.52 to 3.78 represent the same structure of study sites of upper Assam and tropical forests of Indian subcontinent. Differences in species diversity between communities generally resulted from variations in site specificity [37]. Moreover, it is often correlated with rainfall and nutrient status of the site [38]. Although species diversity was high, the high similarity indices (34.25% to 75.38%) among different study sites indicate that floristic composition is characteristically similar in the region, may be because of common cultural interest of household owners. High diversity and low concentration dominance in study sites may be due to different levels of anthropogenic pressure in different sites.

5. Conclusions

The widespread cultivation of A. malaccensis in upper Assam, northeast India, offers a potential ex situ reservoir for the future conservation and management of this threatened tree. However, genetic diversity of such rare species of forest origin may be affected in managed ecosystems due to limited gene flow, inbreeding, and selection pressure. A thorough investigation of the genetic variation of the A. malaccensis cultivations investigated here is needed before their potential value to the ex situ conservation of this species can be confirmed.

Conflict of Interests

The authors (Dr. P. Saikia and Professor M. L. Khan) declare that there is no conflict of interests regarding the publication of this paper.

Acknowledgments

The authors would like to express their sincere gratitude towards the people of upper Assam, for the free access to their homegardens, for their cooperation during the survey and interviews, and for the permission to collect plant samples. Financial support from DBT, Govt. of India, through the project “Mapping and quantitative assessment of geographic distribution and population status of plant resources of Eastern Himalayan region” is highly acknowledged.

References

Anonymous, “Review of Significant Trade Aquilaria malaccensis,” http://www.cites.org/sites/default/files/eng/com/pc/14/E-PC14-09-02-02-A2.pdf

CITES, “Resolution,” in Proceedings of the 9th Meeting of the Conference of the Parties (COP '94), Fort Lauderdale, Fla, USA, November 1994.

IUCN, Asian Regional Workshop (Conservation & Sustainable Management of Trees, Viet Nam) 1998, Aquilaria malaccensis. In: IUCN 2009, IUCN Red List of Threatened Species, Version 2009.2, 2010, http://www.iucnredlist.org

P. Saikia and M. L. Khan, “Agar (Aquilaria malaccensis Lam.): a promising crop in the homegardens of Upper Assam, Northeastern India,” Journal of Tropical Agriculture, vol. 50, pp. 8–14, 2011.

P. Saikia, B. I. Choudhury, and M. L. Khan, “Floristic composition and plant utilization pattern in homegardens of Upper Assam, India,” Tropical Ecology, vol. 53, no. 1, pp. 105–118, 2012.

P. Saikia and M. L. Khan, “Aquilaria malaccensis Lam., a Red-listed and highly exploited tree species in the Assamese home garden,” Current Science, vol. 102, no. 4, pp. 546–547, 2012.

S. C. Nath and N. Saikia, “Indigenous knowledge on utility and utilitarian aspects of Aquilaria malaccensis Lamk. in northeast India,” Indian Journal of Traditional Knowledge, vol. 1, no. 1, pp. 47–58, 2002.

N. Parthasarathy, “Tree diversity and distribution in undisturbed and human-impacted sites of tropical wet evergreen forest in southern Western Ghats, India,” Biodiversity and Conservation, vol. 8, no. 10, pp. 1365–1381, 1999.

H. Padalia, N. Chauhan, M. C. Porwal, and P. S. Roy, “Phytosociological observations on tree species diversity of Andaman Islands, India,” Current Science, vol. 87, no. 6, pp. 799–806, 2004.

Census of India, Census Report, Ministry of Home Affairs, Government of India, 2001.

P. Saikia, Population structure and conservation practices of Aquilaria malaccensis Lam. in homegardens of upper Assam and its prospects in socio-economic development [Ph.D. thesis], Department of Forestry, NERIST (Deemed University), Arunachal Pradesh, India, 2011.

R. Misra, Ecology Workbook, Oxford & IBH Publishing Company, Calcutta, India, 1968.

A. F. Magurran, Ecological Diversity and Its Measurement, Princeton University Press, Princeton, NJ, USA, 1988.

C. E. Shannon and W. Wiener, The Mathematical Theory of Communities, University of Illinois Press, Urbana, Ill, USA, 1963.

E. H. Simpson, “Measurement of diversity,” Nature, vol. 163, article 688, 1949.

T. Sørenson, “A method of establishing groups of equal amplitude on similarity of species content,” Biologiske Skrifter K. Danske Videnskbernes Selskab, vol. 5, pp. 1–34, 1948.

W. G. Whitford, “Distribution of woodland plants in relation to succession and clonal growth,” Ecology, vol. 30, no. 2, pp. 199–208, 1949.

J. T. Curtis and G. Cottam, Plant Ecology Work Book, Laboratory Field Reference Manual, Burgess, Minneapolis, Minn, USA, 1956.

J. E. Gordon and A. C. Newton, “Efficient floristic inventory for the assessment of tropical tree diversity: a comparative test of four alternative approaches,” Forest Ecology and Management, vol. 237, no. 1–3, pp. 564–573, 2006.

D. Jose, “Structure and productivity of the homegardens of Kerala: a case study,” in Proceeding of the 4th Kerala Science Congress, C. G. R. Nair, Ed., pp. 17–19, Science, Technology and Environment Department, Government of Kerala, Thiruvananthapuram, India, 1992.

E. P. Odum, Ecology, Holt, Reinhart and Winston, New York, NY, USA, 2005.

S. P. Hubbell, R. B. Foster, S. T. O'Brien et al., “Light-gap disturbances, recruitment limitation, and tree diversity in a neotropical forest,” Science, vol. 283, no. 5401, pp. 554–557, 1999.

H. T. Odum, Fundamentals of Ecology, W.B. Saunders, Phiadelphia, Pa, USA, 1971.

U. K. Sahoo, P. Rocky, K. Vanlalhriatpuia, and K. Upadhyaya, “Structural diversity and functional dynamism of traditional home gardens of North-East India,” The Bioscan, vol. 1, pp. 159–171, 2010.

L. N. Trinh, J. W. Watson, N. N. Hue et al., “Agrobiodiversity conservation and development in Vietnamese home gardens,” Agriculture, Ecosystems and Environment, vol. 97, no. 1–3, pp. 317–344, 2003.

K. Kehlenbeck and B. L. Maass, “Crop diversity and classification of homegardens in Central Sulawesi, Indonesia,” Agroforestry Systems, vol. 63, no. 1, pp. 53–62, 2005.

O. T. Coomes and N. Ban, “Cultivated plant species diversity in home gardens of an amazonian peasant village in Northeastern Peru,” Economic Botany, vol. 58, no. 3, pp. 420–434, 2004.

R. K. Verma, K. S. Kapoor, S. P. Subramani, and R. S. Rawat, “Evaluation of plant diversity and soil quality under plantation raised in surface mined areas,” Indian Journal of Forestry, vol. 27, no. 2, pp. 227–233, 2004.

T. Das and A. K. Das, “Inventorying plant biodiversity in homegardens: a case study in Barak Valley, Assam, North East India,” Current Science, vol. 89, no. 1, pp. 155–163, 2005.

C. Padoch and W. de Jong, “The house gardens of Santa Rosa: diversity and variability in an amazonian agricultural system,” Economic Botany, vol. 45, no. 2, pp. 166–175, 1991.

B. M. Kumar, S. J. George, and S. Chinnamani, “Diversity, structure and standing stock of wood in the homegardens of Kerala in peninsular India,” Agroforestry Systems, vol. 25, no. 3, pp. 243–262, 1994.

Z. L. Dao, W. S. Chen, H. J. Guo, H. L. Duan, and J. G. Duan, “Household based agrobiodiversity assessment (HH-ABA) of house garden in Hanlong village of Baosha, east slope of Gaoligong Mountains,” Acta Botanica Yunnanica, supplement 12, pp. 102–112, 2000 (Chinese).

P. Bhuyan, M. L. Khan, and R. S. Tripathi, “Tree diversity and population structure in undisturbed and human-impacted stands of tropical wet evergreen forest in Arunachal Pradesh, Eastern Himalayas, India,” Biodiversity and Conservation, vol. 12, no. 8, pp. 1753–1773, 2003.

N. Parthasarathy, V. Kinhal, and L. P. Kumar, “Plant species diversity and human impacts in the tropical wet evergreen forests of southern Western Ghats,” in Proceedings of the Indo-French Workshop on Tropical Forest Ecosystems: Natural Functioning and Anthropogenic Impact, pp. 26–27, French Institute, Puducherry, India, November 1992.

J. S. Singh, Y. S. Rawat, and O. P. Chaturvedi, “Replacement of oak forest with pine in the Himalaya affects the nitrogen cycle,” Nature, vol. 311, no. 5981, pp. 54–56, 1984.

N. Visalakshi, “Vegetation analysis of two tropical dry evergreen forests in southern India,” Tropical Ecology, vol. 36, no. 1, pp. 117–127, 1995.

J. S. Denslow, “Gap partitioning among tropical rainforest trees,” Biotropica, vol. 12, no. 2, pp. 47–55, 1980.

G. S. Hartshorn, “Neotropical forest dynamics,” Biotropica, vol. 12, no. 2, supplement, pp. 23–30, 1980.