13 J OURNAL OF FOREST PRODUCTS & INDUSTRIES , 2013, 2(1), 13-20 ISSN:2325 – 4513(PRINT) ISSN 2325 - 453X (ONLINE )
Effect of Felling Period and Types on Acacia seyal (Del) Ability to Generate by Sprouts in Rawashda Forest, Gedarif State, Sudan Mohamed T. A. Eltayb1 and Talaat D. Abdel Magid2 1
Forest National Corporation Sinnar State, E-mail: emohamedtom@yahoo.com University of Bahri, College of Natural resources and Environmental Studies, E-mail: talaat1957@yahoo.com Tel: 00249918110780 (Received November 14, 2012; Accepted December 16, 2012)
2
] Abstract— The Forests National Corporation (FNC) in Sudan face with so many problems in protection and management of Acacia seyal due to malpractices used by noxious nomads and local people in reserved forest. Where illicit felling of trees occurred by nomads in a bit to feed their animals, beside the traditional practices that use for Acacia seyal trees to produce wood products (fire wood, charcoal and building poles) the using of unsound fasion style of Acacia seyal management lead to high loss of revenues beside high cost operational processes used for replanting the felled areas. Therefore the study aimed to improve Acacia seyal management by the determining the effect of felling period and techniques use for managing Acacia seyal. The main objective was to test the hypothesis that the Acacia seyal has ability to produce second yield of fire wood and building poles from coppicing after 20 years of felling. The study was conducted during the period (1988- 2009) in Rawashda forest reserve, Gadarif state, eastern Sudan. Four replicates were used. Two types of felling were adopted in each plot, within each period of time (July, October, February and May). Mean yield for specific periods was determined in volume term. The primary information on the yield (Value m3) of twenty years old coppiced and lopped A.seyal variety seyal was investigated; whereas the proper period and type of felling were determined in the field. The study showed that commercial yield (volume) of A.seyal product is possible from coppiced and lopped trees. The mean volume obtained per tree ranged between 0.0641 and 0.0784 m3 for charcoal felling in May and July respectively and between 0.0584 and 0.0703 m3 for lopping in July and May. However the result will boost the efforts towards management of A.seyal in the future and it can be selected as a systematize process for management, to prevent a losable product and to attain economic commercial yield, with predictable economic sustainability. This result claimed to be the first report that showed and confirmed a tradable product from a 20 years coppiced and lopped Acacia seyal in Sudan. Which can beseem to be described as a pioneer work in field of A.seyal management.
Index Terms— Rawashda forest, A.seyal period, Felling type, Management
I. INTRODUCTION
A
cacia seyal (Del.) belongs to family Mimosaceae is a tree of the African semi-arid zone. The tree distributes from Senegal across the entire Sahel to the Sudan and Egypt, and from East Africa from Somalia to Mozambique and westwards to Namibia with different varieties A.seyal on favourable sites produces fast juvenile growth (more than one m per year), maximum height reached after 8-10 years [1]. There are about 800 species, of the genus Acacia. They are abundant in savannah and arid regions of Australia, Africa, India and the Americas. Many are exceedingly robust and grow under the most severe conditions [4]. It has valuable forage in time of shortages, herdsmen cut down branches for leaves and pods’ i.e. lopping is a common practice. A.seyal is one of a genus Acacia spread from humid tropical to dry desert condition [2]. Acacia seyal predominantly a tree of the cracking clay soil found in large almost pure stands or mixed with A. senegal and Balanites aegyptiaca under rainfalls of 250 to 1000 mm. under low rainfalls on water- receiving sites and depressions. Confined in the Flood Region to low elevation intermittently flooded by rain [3]. The great promise of Acacias forage it’s suitability for dry regions, where pasture grows poorly or only seasonally, the leaves, pods or young shoots provide mainly the main browse for animals and have fair to excellent palatability for domestic livestock such as cattle, sheep, goat, donkey and camel. Most Acacias grow vigorously, coppice readily and withstand heavy browsing. The leafy branches can be cut for fodder within season without significant damage to tree [4]. Many Acacias have a fast growing tap root that enable them to utilize moisture stored in lower soil layers and to remain green long in the dry season [4]. Both the foliage and pods are potentially edible. The bark and some fresh young stems are also relished by certain animals. Bees are the likely pollinators. Flowers are borne in profusion and are spicy scented or sweet smelling. The seeds of A. seyal. var. seyal are locally dispersed in large amounts and have been found deposited in animal feces along transhumance routes [5]. Honey production can often supplement forage
14 J OURNAL OF FOREST PRODUCTS & INDUSTRIES , 2013, 2(1), 13-20 ISSN:2325 – 4513(PRINT) ISSN 2325 - 453X (ONLINE ) production. NFTA say that Acacia nectar is unequalled in tropics for producing honey [2]. As reported by [6]. The tree number one in Sudan is Acacia seyal and its potential has never been fully explored but is promising. A. seyal is a multi-purpose producing excellent fuel wood; charcoal animal fodder and gum.70% of Sudanese energy budget is from fuel wood [7]. The species regenerates freely by coppicing and seeds [1]. FNC established A.seyal plantations by seedlings and seeds during plantation season in all reserved forests. But this type of plantations are costive due to many required operations such as raising of seedlings, transportation, flying nurseries, land ploughing, planting out and other costly activities. Also the harvesting of A.seyal nowadays by wood merchants, in reserved forests whom gained the tender to produce charcoal, building poles and firewood .e.g. in Sennar state okalma forest compartment harvested during 2008 mean volume of one tree produces 0.0311-0.0355 m3 [8] .i.e. There is no proper systematic method adopted, for harvesting of Acacia seyal to gain sustainable management.
Experiment Design 4.2 hectare well stocked by natural Acacia seyal variety seyal was selected in 1988, fenced using barbed wire, metallic posts and well guarded. The age of selected A.seyal stand was reached its final rotation 15 years old as reported by [9]. The selected site was divided into four blocks, each block was divided into four plots (50x50 m) surrounded by buffer zone. Trees were numbered inside each plot in clock wise pattern. Felling operation of trees was done using axes , and two types of charcoal felling(CF)were used, in which 30 cm stump left(Plate 1), and nomads or herder felling or lopping (NF) in which the trees cut, above the breast height (Plate 3). Rainfalls during experiment period were recorded using range gauge.
The problem impose itself here is that, as the cutting operation usually happened in different period of times, some of these operations produce products susceptible to be damaged by insect, caused loss of high portion of the product, in addition to that stumps have not able to produce good sprouts. The question of the research is how to attain economic commercial yield, with predictable economic sustainability. Information of A.seyal researches, devoted to improving the cultivation and production of A.seyal, is very meagre. The actual commercial yields of coppiced and lopped A.seyal trees are not recognized yet. . Even today it is not well known the proper process or technique that can be applied to produce a commercial yield and a proper time of felling. .i.e. we are ignoring the suitable technique of felling A.seyal trees, for producing charcoal, firewood and building poles. in the same time, to generate naturally by coppicing and sprouting giving a commercial yield. This research aimed to determine suitable process, for harvesting A.seyal to obtain a commercial yield and replace the high cost of different replanting. The specific objective was to test the hypothesis that A.seyal produces, commercial product in the second harvesting period concerning coppiced and lopped trees, after twenty year. This may help in low cost sustainable management of A.seyal. II. MATERIALS AND METHODS The study was conducted during the period (1988-2009) in Rawashda natural reserve forest (52500 ha) divided in to 8 compartments covered with different species dominated by Acacia seyal, Gedarif state, eastern Sudan, which lies between latitude 12º 25´ and 14º 15´ and longitude 34º 37º planed to produce charcoal, fire wood and building poles.
Plate (1): Charcoal felling type Photo courtesy: Mohamed Tom (1988)
15 J OURNAL OF FOREST PRODUCTS & INDUSTRIES , 2013, 2(1), 13-20 ISSN:2325 – 4513(PRINT) ISSN 2325 - 453X (ONLINE )
Plate (2): Lopping type Photo courtesy: Mohamed Tom (1992) The two types of felling were done in each plot i.e. half of the the data were collected for diameters at breast height DBH plot was lopped and the other half was completely felled (CF). (cm), height H (m) and number of sprouts (N) for each lopped The felling was done within different period of the year, where and coppiced trees in each plots using measuring tape, the first felling was in July, in which four plots were selected callipers and heights meter or sunnto. Data were recorded also randomly, axes were used for the two types of felling (CF and for the buffer trees, hundred trees which were selected NF),. The first felling called felling at mid of rainy season and randomly and their DBH and height (H) were measured. labelled by A1, A2, A3 and A4 (Figure 1). The second felling Volumes (V) were calculated using the following formula: was done at the end of the rainy season (October). Four plots were selected randomly, from the four blocks and felled (CF V (m3) = (DBH (cm)) ² x П H(m) x N x F40000 and NF) in both half’s of each selected plots and labelled by Where: DBH = Diameter at breast height in (cm) B1, B2, B3 and B4 (Fig. 1). The same process was done in П = 3.14 February and labelled by C1, C2 C3 and C4 (Fig. 1). The last H = height (m) cutting was done in the last four plots D1, D2, D3 and D4 in N = number of trees the end of dry season (May) (Fig 1). F= form factor (0.5) The site was protected and guarded by FNC because it was a part of reserve forest, and in the vicinity of this experiment the main guarding settlement was established. By the end of 2008, 1 50m D4 50m
2 B8
3 C1
4 D16
2
D7
B11
C15
B2
A6
A10
A14
C1
C5
D9
B13
A3
Buffer
Figure (1): Experiment Design A = Felled at mid of rainy season July 1988. B = Felled at end of rainy season October 1988. C = Felled at mid of dry season February 1989. D = Felled at end of dry season May 1989 Plot = 50m x 50m.
16 J OURNAL OF FOREST PRODUCTS & INDUSTRIES , 2013, 2(1), 13-20 ISSN:2325 – 4513(PRINT) ISSN 2325 - 453X (ONLINE ) Data analysis: data were analyzed used statistical analysis SPSS verion. 11.5. The variable tested was done using bivariate correlation two tailed test of significance.
III. RESULTS AND DISCUSSION The results in Table (1), figure (2) and (3) revealed that the mean yield (volume) obtained from 20 years old coppiced and lopped trees of Acacia seyal is 0.0516 m3 and 0.0584 m3 , respectively. The correlation volume per tree of A.seyal in the buffer zone (35 years old) and volume per tree of coppiced (20 years old) show no difference (App.1). These findings reflect that age (35 years) the annual increment (volume increase per year) is very low particularly between the ranges 20-35 years. .However, the volume obtained from coppiced tree is equal to that reported by Inventory Sector, Sennar state. The mean volume of single tree was found in Okalma forest to be (0.0475 m3) and Nowara forest was (0.0355 m3) while Inventory Sector in eastern region (Kassala) reported (2009), (0.0613 m3) per tree in Rawashda forest Table (2). However, [10] reported in Khor Donia Forest 11.3 m3 per Feddan (0.055 m3) per tree of A. seyal 20 years old. The result also showed that the mean yield of surrounding tree (Buffer zone) of the experiment was found to be (0.0554 m3) which laid in the same range of the mean volume of single coppiced and lopped trees that reflect the value of coppicing and lopping process in achieving a commercial volume of product which can be recommended for managing Acacia seyal. This finding agrees with [4] who reported that Acacia has vigorously growth and ability to coppice. The study results also revealed that the period of felling affected the yield of
A.seyal where the high yield was achieved in the mid of rainy season (July) this in agreement with [1] stated that wood durability maybe improved by water storage, this is actually obtained during rainy season in charcoal felling while the high value also achieved in nomad felling by the end of dry season (May) Figure (2) and (3) (plate 2, 3). The mean volume produced by charcoal felling process in July and May was (0.0784 m3) and (0.0641 m3), respectively. The lowest values were obtained in October (0.0315m3) and February (0.0324 m3). The lopped sprouts produced high production in July (0.0584m3 3), October (0.0598 m3) and May (0.0703 m3). The lowest volume was in February (0.0451 m3). However charcoal process is better operation for managing Acacia seyal than lopping process, although the lopping process gave commercial yield in the final production when operation conducted in favourable conditions. Because charcoal process produced in the first felling high yield (the tree was cutting completely) but lopping process allows only partial felling of trees in the first felling. This result is in line with [11] who stated that coppicing of Acacia seyal variety seyal is possible for regeneration of Acacia seyal within the age of (5 – 10, 10 – 15 and 15 – 20) years; but showed vigorously growth in age 15, 10 years when, the rain fall is adequate. Moreover, the findings also in line with [4] and [12] which reported that, Acacia have vigorous growth and ability to coppice. The study results revealed that the lopping process shows high yield of sprouts vigorously which contradict with [13] who stated that evaluation of the response to lopping and cutting of A.seyal indicated limited recovery capacity in mature trees.
0.08 0.07
Mean volume (m2)
0.06 0.05 0.04 0.03 0.02
0.01 0 July (A)
Oct.(B)
Feb.(C)
May (D)
Total mean
Standard control
Period of felling
Figure (2): Mean yield (volume m3) of coppiced A.seyal trees, charcoal felling 20 year old felled during different period of the year, total mean and yield of control.
17 J OURNAL OF FOREST PRODUCTS & INDUSTRIES , 2013, 2(1), 13-20 ISSN:2325 – 4513(PRINT) ISSN 2325 - 453X (ONLINE )
Table (1) The mean yield (20 years) of coppiced and lopped Acacia seyal in Rawashda forest Rep. Type of felling
Nomads felling (lopping )
2
Mean DBH (cm)
Mean Height (H) M
Mean no. of trees (N)
July (A) Octobe r (B) Feb.(c)
12.00
8.00
1.40
Mean volum e (v) m3 0.0634
10.00
8.00
1.00
0.0314
15.00
9.60
1.80
0.0157
May(D)
14.40
10.24
1.10
0.0477
Total mean
12.85
8.96
1.33
0.0396
July (A) Octobe r (B) Feb.(C)
10.00
8.10
1.50
0.0477
16.00
9.90
1.60
0.1052
14.40
7.00
1.30
0.0915
May(D)
14.40
10.50
1.30
0.1112
Total mean
13.35
8.88
1.43
0.0889
Period
Charcoa l felling
1
3
Mea n DB H (cm) 13.0 0 10.0 0 10.0 0 14.0 0 11.7 5 14.0 0 8.00
Mean Heig ht (H) m 9.60
Mea n no. of trees 1.20 (N)
Mean volum e (v) m3
7.50
1.30
0.0383
8.50
1.20
0.0401
10.70
1.10
0.0745
9.08
1.20
0.0572
10.40
1.30
0.1041
7.00
1.90
0.0334
11.0 0 11.0 0 11.0 0
10.30
1.00
0.0490
9.20
1.40
0.0612
9.23
1.40
0.0619
0.0757
4
Mea n DB H (cm) 16.0 0 10.0 0 10.0 0 13.0 0 12.2 5 11.0 0 8.00
Mean Heig ht (H) m 10.00
Mean no. of trees (N)
7.30
1.00
8.50
1.20
9.50
1.20
8.83
1.10
9.40
1.50
6.80
1.70
11.0 0 14.0 0 11.0 0
10.30
1.00
9.50
1.20
9.00
1.35
1.00
Mean volu me (v) m3 0.100 6 0.022 7 0.040 1 0.060 6 0.057 5 0.067 0 0.029 1 0.049 0 0.087 8 0.058 2
Mea n DB H (cm) 12.0 0 10.0 0 10.0 0 14.0 0 11.5 0 12.0 0 0.70
Mean Heig ht (H) m 8.70
Mean no. of trees (N)
7.00
1.00
8.60
1.00
10.00
1.10
8.58
1.15
8.90
1.50
7.3
1.50
10.0 0 10.9 0 10.6 5
8.80
1.00
9.00
1.40
8.50
1.35
1.50
Mean volu me (v) m3 0.073 8 0.027 6 0.033 8 0.068 4 0.050 9 0.075 5 0.021 1 0.034 6 0.049 5 0.045 2
Mean volume (m3) Per tree of Per expt. tree of BT 0.0784
0.05
0.0315
0.05
0.0324
0.05
0.0641
0.05
0.0516
0.05
0.0584
0.05
0.0598
0.05
0.0451
0.05
0.0703
0.05
0.0584
0.05
18 J OURNAL OF FOREST PRODUCTS & INDUSTRIES, 2013, 2(1), 13-20 ISSN:2325 – 4513(PRINT) ISSN 2325 - 453X (ONLINE ) Table (2) Compartment number, total area (feddans) ,mean volume (m2) of Acacia seyal trees, number of the trees per compartment and mean volume (m3) per tree. Compartment Area (feddans) per Mean volume (m3) of trees Mean number of trees Number of trees per number compartment per compartment per feddan compartment 1 2171.40 1441.070 21.00 45599.40 2 375.08 1523.055 68.00 25505.44 3 1168.08 1315.993 13.00 15185.04 4 7241.88 10.606.975 19.00 137595.72 5 22006.18 16.652.238 14.00 308086.52 6 25406.52 97.815.666 62.00 1575204.24 7 2864.99 5.007.060 32.00 91679.68 8 1864.14 1.223.060 12.00 22369.68 Total 63.098.27 149.302.612 241.00 2.221.225.72 Mean 7887.28 18662.826 30.125 277653.21 Source: [8].Inventory Sector, Kassala State measuring 8 compartments (1 ــــــــــــ8) of Rawashda forest during the period 2008-2009, and determined the volume of trees in each compartment and hence the mean volume per tree of Acacia seyal variety seyal. Table (2).
Figure (3): Mean yield (volume m3) of lopped A.seyal trees, herdsmen Nomads felling 20 year old, felled during different period of the year, total mean and yield of control.
Plate (3): Sprouts of lopped trees of A.seyal variety seyal 20 years old. Photo courtesy: Mohamed Tom (2009)
Mean (m3) 0.0316 0.0597 0.0866 0.0771 0.0541 0.0621 0.0546 0.0547 0.4905 0.0613
Volume
19 J OURNAL OF FOREST PRODUCTS & INDUSTRIES, 2013, 2(1), 13-20 ISSN:2325 – 4513(PRINT) ISSN 2325 - 453X (ONLINE )
Plate (4): Coppice of A.seyal variety seyal 20 years old. Photo courtesy: Mohamed Tom (2009) IV. CONCLUSIONS The study results confirmed the importance of felling period and type in A.seyal growth and production. This may gave the way for proper management of Acacia seyal in order to increase production and replanting operation. Since the results showed that commercial yield of A.seyal is possible from coppicing and lopping sprouts. This process will reduce the cost of replanting, tending operation and loss of crop during felling in unfavourable periods. The study result also revealed that the best felling of A.seyal was at age 15-20 years, which is recommended for tree rotation
REFERENCES [1] Maydell. H,J (1990).Trees and shrubs of the Sahel, their characteristics and uses. GTZ. Weikersheim Pp. 137-139. [2] NFTA (1994). Quick guide to useful nitrogen fixing trees from round the world. NFT highlights. Pp 94-107. [3] Abdel Magid, T D and Badi, K H (2008). Ecological zones of the Sudan. Nile Trans-Boundary Environmental Action Project. A paper presented in the workshop on the importance of wetland in Sudan. Khartoum. Pp. 2-3
[4] National Academy of Sciences (1979). Tropical legumes: Resources for the future, Washington DC p. 123. [5] ICRAF. (2009). Agro-forestry data base. Nairobi, Kenya [6] Abdel Nour. H.O (2008). Integrated pest management in Sudan’s Forests, A strategy to protect what is left of Sudan’s Forest pp.15. [7] FNC (1995). The forest product consumption survey in the Sudan. Forest Development Project FAO-GCP-SVO047/net. Pp. 20-24 [8] Inventory Sector. (2009). Inventory Sector of the Eastern states (Gadarif, Kassala, and Red Sea States). Pp 1011 [9] Vink, A.T. (1990). Growth of Acacia seyal: analysis of 1987-1990 measurement in Rawashda forest Field document No. 38. Fuelwood Development Project for energy in Sudan. [10]Goda,S.Bayomi,A.Abdalla, Ead lmola, A. and Abdel Magid, T.D (1989). Report on social and economical impact of large scale Eucalyptus planting. Forest AdministrationKhartoum. Pp. 80-82. [11] Yasin.B.M.(2008). Regeneration of Acacia seyal variety seyal in Gedarif state, M.Sc. Thesis, Faculty of forestry, University of Khartoum. Pp. 30 [12] Hussein,S.G.(1998). Afforestation in arid lands with particular reference to the Sudan. Desertification and desert cultivation studies Institute. UNESO chair of desertification. University of Khartoum. [13] Orwa et al. (2009) Acacia seyal. Agroforestry database 4.0. A tree reference and selection guide. www.winrock.org/forestry/factnet.html pp. 1-5
20 J OURNAL OF FOREST PRODUCTS & INDUSTRIES , 2013, 2(1), 13-20 ISSN:2325 – 4513(PRINT) ISSN 2325 - 453X (ONLINE ) Appendixes: App1: Correlation between volume (m3) per tree of A.seyal buffer and volume per tree coppice (20years old)
Charcoal felling period
Nomads lopping felling period
Charcoal felling period
Nomads lopping felling period
per tree of exp. volume cubic meter
per tree of buffer volume cubic meter
Pearson Correlation
1
1.000(**)
-.231
.(a)
Sig. (2-tailed)
.
.
.769
.
Sum of Squares and Cross-products
5.000
5.000
-.021
.000
Covariance
1.667
1.667
-.007
.000
N
4
4
4
4
Pearson Correlation
1.000(**)
1
-.231
.(a)
Sig. (2-tailed)
.
.
.769
.
Sum of Squares and Cross-products
5.000
5.000
-.021
.000
Covariance
1.667
1.667
-.007
.000
4
4
4
4
Pearson Correlation
-.231
-.231
1
.(a)
Sig. (2-tailed)
.769
.769
.
.
Sum of Squares and Cross-products
-.021
-.021
.002
.000
Covariance
-.007
-.007
.001
.000
N
4
4
4
4
Pearson Correlation
.(a)
.(a)
.(a)
.(a)
Sig. (2-tailed)
.
.
.
.
Sum of Squares and Cross-products
.000
.000
.000
.000
Covariance
.000
.000
.000
.000
4
4
4
N per tree of exp. volume cubic meter
per tree of buffer volume cubic meter
N
4 ** Correlation is significant at the 0.01 level (2-tailed). a cannot be computed because at least one of the variables is constant.