Showing posts with label Floral Diversity. Show all posts
Showing posts with label Floral Diversity. Show all posts

Friday, June 6, 2008

Floral Diversity


Preliminary Results on the Impact of the Nomadic Grazing on Floral Diversity in Miandam, Swat-Pakistan

Ashiq Ahmad Khan and Syed Kamran Hussain




1. Introduction

Miandam is located in the north east of district Swat, lies between 34o 34′ to 35o - 07′ N latitudes and 72o - 36′ to 73o - 35′ E longitudes in the Hindu Kush mountain range. Miandam valley is a summer resort about 56 km from Saidu Sharif, the capital of Swat. The elevation of the valley ranges from 1200 m to 3660 m. The valley comprises of 11 big villages and 15 small hamlets with a population of about 20,000. The forest of the Miandam valley is a fundamental and potentially sustainable source of many services including economically important medicinal plants. One of the studies reveals that there are 190 plant species, identified so far in Miandam. Out of these 179 are used for the treatment of various health problems [1]. As else where in the forest area, Miandam is also facing the problem of overgrazing and deforestation. The basic reason of deforestation is commercial harvesting. This year 2.6 million cft timber has been extracted from the forest while the illegal and unrecorded extraction is much more.

Due to low level of education and life standard combined with lack of information regarding health and hygiene, people of the valley are suffering from different diseases especially women and children. They depend only on one primary Health center, which is not sufficient for a total of 150 sq km area. Required equipments and medicines are also not available in the said center. The nearest hospital is situated 56 km away, and not in the access of poor local people. Previously people of the valley were relying on herbal remedies as a principal means of preventing and curing illnesses. Beside this collection of medicinal plants from the forest area provides employment and fetches earnings to the poor local people. It has been estimated that almost 3000 people are earning 25% of their total income from the collection and sale of the plants [1]. However, these resources, and local knowledge of these, are being threatened by nomadic grazers. Each year nomads carry more than 40,000 goats to the high altitude of pastures passing and browsing through the young forest crop and shrubs throughout. As per the existing traditions, they have to pay a tax (sum of US $ 85 to 120) to the owners, called "Qalang” for their stay in the pastures. During their stay, in addition to grazing their animals, each nomad collect enormous amount of medicinal plants worth of US $ 450, but the owners of the pastures are not aware of such losses. Since 2000, some of the forest owners put a ban on the nomadic grazers on their land. It has been observed that the area where the nomadic grazing has stopped, showing better vegetation cover, improvement in medicinal plants diversity and good regeneration of pine species.

Thus, first there is an urgent need to study the difference between vegetation cover, plant diversity and regeneration status under grazing and controlled grazing lands. The concluded results will be a good tool for an extension worker to provide awareness to the forest owners about economic importance of their Pastures and adverse effect of nomadic grazing on it.

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2. Review of Literature

Grazing in the grasslands has played a key role in changing the botanical composition, which, however, varies with the type of grass cover, its palatability etc. Overgrazing represent the most obvious impact on the native biodiversity of grasslands. As overgrazing causes retrogression, stimulates growth of weeds and loss of diversity. In Assam overgrazing reduces the tall grass cover to tufted grass type to Chrysopogon aciculatus and Imperata cyclindrica [4].

Livestock impact on biodiversity through trampling and removal of biomass, alteration of species composition through selective consumption and changed inter-plant competition. Changes in grazing intensity and selectivity will inevitably change biodiversity; under grazing and overgrazing can both have negative effects, but overgrazing by livestock is increasingly problematic [9].

Over-grazing has resulted in land erosion, formation of boggy areas and reduction in plant diversity. The area of natural pasture land has declined from 1.4 million ha in 1940 to 808,000 ha today, and remaining areas have been degraded and have become dominated by rocks (87%), scrub (25%), and inedible (74%) or poisonous plants (47%), while diversity has declined. For example, while between 70 and 80 plant species are normally supported by steppe systems, the number of species found after intensive over-grazing drops to around 15 [10].

Grazing animal may exert beneficial or mutual influences on the vegetations for their own good but on the other hand, large concentration of them often have harmful effects on the plants because of selectivity and over grazing. Quantifying the impact of livestock grazing on natural communities (forages) has become a major issue in the management of rangelands especially where the grazing is very widespread and its impacts may be in conflict with conserving biodiversity [5].

According to Lamprey (1979) Grazing is among the important agents, which influence the distribution of some vegetation types. In most rangeland ecosystems, grazing, browsing and other factors such as fire and climate contribute to vegetation change. Grazing animals influence species composition, change in biomass and distribution of biodiversity [8].

According to Pratt and Gwynne, (1997) Overgrazing reduces the ground cover vegetation, plant diversity and productivity. The impact of grazing on rangeland vegetation depends on three factors: (a) the type of herbivores (grazers and browsers) (b) Number and type of animals utilizing an area (c) Distribution of use in time and space

3. Methodology

A line transect survey technique was adopted in accordance with the popular and locality specific procedures of Akbar (2000), Kent and Coker (1995) and Cox (1967). For comparative assessment, data were collected from 2 sites, one; that is protected by the locals from nomadic grazing, while, other that is open to grazing.

Before data collection, a reconnaissance survey was conducted to make sure that all other factors like Aspect, Altitude and Slope remain constant in both the sites; the only variable is grazing pressure. Data were collected from two different sites through different techniques:

ransect walk to ascertain total number of plant species available in each site along the transect

Sample Plot (Quadrate of 5 X 5 M) to collect detailed information about the 10 selected species, which are economically important.

Sample plots (Quadrate of 5x5m size) in each site were taken at uniform intervals along continuous transects. The plots were taken on main transect and on rows laid in four directions from a systematically selected point. In general, the plots were approached along the transect walking upstream on a track and from their lower positions, across the slopes on rows.

The first plot was fixed in the start of the track. From the fixed point on the transect, after every 200 meters (300 steps), to both right and left ridges on the determined angles, quadrates or sample plots of 5x5m were laid. Proceedings ahead on transect upstream another quadrate after 300m was taken. The same process was repeated for taking sample plots on the rows on left and right. In this way the whole site was sampled.

The number of plants of each species, average phenological stage of the plants, general habitat, altitude and aspect of the plot were recorded on a Performa. This was decided well before starting the counting of plants, and practiced throughout, that all those individual plants whose roots were inside or beneath the quadrate line, irrespective of the place of their shoots, were counted. Similarly, in certain species with rhizomes and bunches, forming compact inseparable clusters having difficulty in defining a single individual, the entire bunch or patch was counted as one individual.

4. Results and Discussions

4.1. Topography of the Area

The topography of both sites i.e. protected and unprotected from grazing, is rugged with slopes very steep to precipitous, between 60 to 80 %. Both sites occupy predominantly the northern aspect of the main mountain ridge running in north-east direction. The altitude varies between 1,850 to 2200 m in both the sites. All the three main factors including aspect, slope and altitude that influence the vegetation pattern in an area are (more or less) the same. It could be infer that any change in the vegetation density/diversity will be the impact of different grazing pressure in both the sites.

4.2. Floral Diversity

The study revealed that 37 and 23 medicinal plants species were found in the protected and unprotected site respectively, during the month of April, 2007. In August, 2007 after the monsoon, 33 MP’s species were found in unprotected site, while 78 species were recorded from the site that has been banned for nomadic grazing since 2000. Table 1 & 2 showing name of species, recorded from both the sites.

Table-1 Protected from Nomadic Grazing

S. No

Scientific Name

S. No

Scientific Name

S. No

Scientific Name

1

Acorus calamus

27

Cynodon dactylon

53

Paeonia emodi Wall.

2

Aconitum violaceum

28

Cynoglossum lanceolatum

54

Plantago lanceolata L.

3

Adiantum capillus-veneris L.

29

Dryopteris jaxtaposta christ.

55

Plantago major

4

Adiantum venustum

30

Diospyros lotus

56

Podophyllum emodi Wall.

5

Aesculus indica Coleb. ex Wall.

31

Elaegnus umbellate

57

Podophyllum hexandrum Royle,

6

Allium sativum

32

Fagonia arabica Linn.

58

Primula denticulata Sm.

7

Ajuga bracteosa Benth.

33

Ficus palmate

59

Rubia cordifolia Hochst. ex A. Rich.

8

Amaranthus viridis

34

Fragaria vesica

60

Rumax hastatus

9

Arisaema flavum ( Forssk.) Schott

35

Fumaria indica Pugsley

61

Ricinus communis

10

Arisaema jacquemontii Blume,

36

Geranium wallichianum D. Don,

62

Skimmia laureola Sieb. & Zucc. ex Walp.

11

Artemisia scoparia Waldst. & Kit.

37

Hedera nepalensis K. Koch,

63

Solanum nigrum L.

12

Artimisia brevifolia Wall.

38

Hypericum heterantha

64

Stachyus parviflora Benth.

13

Artimisia vulgaris L.

39

Hypericum perforatum Linn.

65

Salvia moorcorftiana

14

Asparagus adsendens

40

Indegofera trifoliata

66

Swartia elata

15

Avena sativa

41

Isodon rugosus

67

Silene uugaris

16

Berberis lycium Royle.

42

Lanthyrus aphaca

68

Sonchus asper

17

Bergenia ciliata (Haw.) Sternb.

43

Launea procumbens

69

Sambacus wightina

18

Bistorta ampilexicaulis (D. Don) Greene

44

Male fern

70

Taxus buccata

19

Bunium persicum

45

Mentha longifolia

71

Taraxcicum officinale weber

20

Caltha alba Jacquem.

46

Mentha spicata L.

72

Trachysepermum ammi

21

Celtis australis

47

Micromeria biflora

73

Urtica diotica

22

Caralluma edulis Benth. ex Hook. f.

48

Myrsine africana L

74

Valeriana jatamansi Jones.

23

Chenopodium album

49

Nepta govantiana

75

Valeriana wallichii DC.

24

Chamomilla recutita Rauschert.

50

Onosma hispidium

76

Verbena offcinalis L.

25

Chenopodium botrys L.

51

Otostagia limbata

77

Viola biflora L.

26

Corydalis govaniana Wall.

52

Oxalis corniculata

78

Viola serpens Wall.

Table-2 Open to Nomadic Grazing

S. No

Scientific Name

S. No

Scientific Name

S. No

Scientific Name

1

Acorus calamus

12

Corydalis govaniana Wall.

23

Corydalis govaniana Wall.

2

Adiantum venustum

13

Cynodon dactylon

24

Cynodon dactylon

3

Ajuga bracteosa Benth.

14

Cynoglossum lanceolatum

25

Cynoglossum lanceolatum

4

Arisaema jacquemontii Blume,

15

Fragaria vesica

26

Fragaria vesica

5

Artimisia vulgaris L.

16

Geranium wallichianum D. Don,

27

Geranium wallichianum D. Don,

6

Berberis lycium Royle.

17

Hedera nepalensis K. Koch,

28

Hedera nepalensis K. Koch,

7

Bergenia ciliata (Haw.) Sternb.

18

Hypericum heterantha

29

Hypericum heterantha

8

Bistorta ampilexicaulis (D. Don) Greene

19

Indegofera trifoliata

30

Indegofera trifoliata

9

Caltha alba Jacquem.

20

Isodon rugosus

31

Isodon rugosus

10

Cannabis sativa

21

Male fern

32

Male fern

11

Chenopodium album

22

Mentha spicata L.

33

Mentha spicata L.

4.3. Economically Important/Target species

One of the study revealed that there are 190 plant species, identified so far in Miandam, of which 179 are used for the treatment of various health problems [1]. But some are economically very important because pharmaceutical industries need those herbs in an abundant. Grater demand of herbal industries for those species has threatened their occurrence and abundance. Species that have greater values include Bistorta ampilexicaulis, Morchella esculenta, Valeriana wallichii, Adiantum venustum, Viola biflora, Bergenia ciliata, Geranium wallichianum, Berberis lycium, Podophyllum emodi, and Paeonia emodi. Out of the 10 plant species, 4 are nationally endangered, (Red Data Book of IUCN threatened species 1998).Table 3 showing economic importance of those 10 selected species.

Table-3. Medicinal Plants of Miandam Valley: Prices & Quantities harvested

Botanical Name

Prices (Rs/kg) for:

Qty Extracted (kg/yr)

Collector

Retailer

Customer

Bistorta ampilexicaulis

10

12

15

15,000

Morchella esculenta

7,000

10,000

14,000

300

Valeriana wallichii

60

100

130

20,000

Adiantum venustum

16

20

30

12,000

Viola biflora

180

280

450

10,000

Bergenia ciliata

10

20

30

1,000

Geranium wallichianum

40

60

100

1,000

Berberis lycium

80

150

300

100

Podophyllum emodi

75

100

170

100

Paeonia emodi

10

18

30

800

4.4. Density of the Target species

Density, which is the number of plants of particular specie per unit area, is essential to determine the population density. Hence total number of plants of individual specie in the quadrate was counted and extrapolation for the area of the site was applied. The study revealed that the average population density of the target species decreases upto 90% due to nomadic grazing, while two species, Paeonia emodi and Podophyllum emodi were completely vanished due to overgrazing. Table-4 shows density (# of plants/ha) of the target species in both sites.

Table-4 Density of the Target species in both sites

Species

Density (#/ha)

Reduce in %age

Protected

Unprotected

Bistorta ampilexicaulis

53200

3900

92

Valeriana wallichii

2900

533

81

Adiantum venustum

37200

800

79

Viola biflora

13560

1100

91

Bergenia ciliata

240

133

45

Geranium wallichianum

12340

800

93

Berberis lycium

1000

300

70

Paeonia emodi Wall

920

0

No Found

Podophyllum emodi Wall.

320

0

No Found

Test the hypothesis that there is no statistically significant difference in the population density of the target species in both the sites.

X1 (A) Density in protected site

X2 (B) Density in Unprotected Site

d = (A - B)

d2

53200

3900

49300

2.43E+09

2900

533

2367

5602689

37200

800

36400

1.32E+09

13560

1100

12460

1.55E+08

240

133

107

11449

12340

800

11540

1.33E+08

1000

300

700

490000

920

0

920

846400

320

0

320

102400

Total

∑d = 114114

∑d2 = 4.05E+09

N = 9

D = ∑d /N= 114114/9= 12679.3

S2 = {∑ d2 – (∑ d) 2 / N} / N – 1

= 1/8 {4.05E+09 – (114114)2 / 9} = 3.26E+08

S = 19026

t = (D – 0) / S/ √N = 6337.3

The tabulated value of ‘t’ for 8 degree of freedom (df) is 2.306 at significance level 0.05 while the calculated value of ‘t’ is 6337.3, which are much more than 2.306. Therefore null hypothesis of no difference is rejected. We infer that the density of target species in both the sites is differing significantly from one another.

4.5. Frequency of the Target species

Frequency is the occurrence and distribution of a particular plant in a particular site. A plant may have high density with low frequency when the plants generally occur in patches. This will indicate non uniform distribution on the site and any indiscriminate harvest can endanger the species on the site. The plant will also be vulnerable to the local adverse biotic and ecological collapses. Frequency of all the target species from grazed and no grazed land is given in Table-5.

Table-5 Frequency of the Target species in both sites

Species

Frequency in %

Protected

Unprotected

Bistorta ampilexicaulis

100

75

Valeriana wallichii

70

30

Adiantum venustum

90

40

Viola biflora

100

50

Bergenia ciliata

20

10

Geranium wallichianum

80

40

Berberis lycium

50

40

Paeonia emodi Wall

50

0

Podophyllum emodi Wall.

30

0

Comparing the plants frequency of both, protected and unprotected sites shows that there is a clear relation between frequency and overgrazing. The study revealed that the sites banned for nomadic grazing showing uniform distribution of all the target species on the site. On the other hand in unprotected site, frequency occurrence of some of target species was restricted to the steep slops only. Maximum decrease in frequency was recorder in Valeriana wallichii followed by Viola biflora while Paeonia emodi and Podophyllum emodi were completely disappeared from the overgrazed site. The adverse impacts of overgrazing are severe more in terms of frequency than on density. Some plants may have low density with high frequency where the plants will have uniform distribution in a particular site. The harvest of such plants could be safe because of its occurrence throughout the site and the plant will not be threatened if some limits of harvest are imposed. Form the above one can infer that the impact of overgrazing on Valeriana wallichii is more severe as compare to Bistorta ampilexicaulis.

4.6. Overgrazing and Natural Regeneration of Pine Trees

During the survey, sapling of Pine trees was also counted in the quadrate while mother trees were calculated through full enumeration. It has been observed that overgrazing had negative impact on the natural regeneration of pine trees. Total number of plants recorded from protected site were 840 while those from unprotected were 66 saplings/ha. This could jointly be attributed to the presence of low number of mother trees, but this could not be regarded that much significant. According to Khattak et al, 1965, 24 mature trees/ha is required to established good regeneration in the moist temperate zone[3], while during survey 27 mother trees/ha has been recorded from the unprotected site. From the above one can infer that the major contributing factor that signifies is the over grazing resulting in much reduced regeneration capability of the forest.

5. Conclusion

There is grate scope of utilizing medicinal plants for improving the livelihood of rural poor especially in the northern parts of Pakistan. Miandam is rich in floral diversity, particularly in medicinal plants. So far 190 plant species were recorded from the area in out of these 179 have medicinal value. However, these precious resources are facing a tremendous danger due to the nomadic grazing thus threatening their occurrence and abundance in its natural habitat.

Results of the study indicate that overgrazing represent the most obvious impact on the floral diversity. The areas which were opened to nomadic grazing shows a massive decline in their density, frequency and specie diversity. 33 species were only found in the unprotected site making a huge difference of 78 species in the site banned for nomadic grazing. Similarly 90 % decline is observed in the population density of MP’s from the area open to nomadic grazing. The effect of the nomadic grazing in term of the occurrence and distribution of the plants are more severe as it effects the uniform distribution of the plant species and any indiscriminate harvest can endanger the species like Paeonia emodi and Podophyllum emodi were completely disappeared from the overgrazed site.

The study concludes that nomadic grazing has resulted in the reduction of the floral diversity and this issue must be addressed on the priority bases. The areas which have diverse species of medicinal plants must be banned for the nomadic grazers.

References

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