CC BY
17TETRACLINIS ARTICULATA REGENERATION (THE THUYA OF THE MAGHREB) AND ITS RESISTANCE TO HUMAN CAUSED DETERIORATIONS: CASE OF FIRE
F. Toumi, A. Rahmani, M. Benyahia, M. Aroussi
Faculty of Sciences Department of Environmental Science B. P. 89 de Sidi Bel Abbes 22000 ALGERIA *Author name: Fouzia Toumi BP 28, Adim Fatiha Post office - Sidi Bel Abbes 22000 - ALGERIA E-mail: [email protected]
Received: 1 Oct 2007; accepted: 27 Nov 2007
Tetraclinis Articulata (The Thuya of the Maghreb) is one of the threatened species, in its ecological area where it is endemic, not only under pressure of animal and human effects, but especially fire, currently, this formation knows an alarming regression although it has the ability to regenerate very often quickly, so it plays an important role preserving the vegetable covertures in the semi-arid areas.
The purpose of this work is to check the regeneration of Thuya through dendrometric characteristics: annual increase of height and diameter, this will allow us to know more about this vegetable formation bringing to light all its potentialities in the eco-development of spaces and to emphasize the degraded and marginalized zones. The results obtained in the three facies will prove the resistant aspect of Thuya against alternations such as fire meanwhile it's imperatively advised to fight against all risks of regression of this vegetable formation.
Keywords: increase, dendrometry, phyto-ecology, facies, forest of Tenira (west of Algeria)
Post: Teacher at the University of Djillali Liabes of Sidi Bel Abbes, Faculty of sciences (1995-2007). Scientific degree: Magister of applied ecology science.
Experience: Engineer in University (1988-1995); responsible of lessons (1995-2007). Scientific research project: Member of ecodevelopment spaces laboratory. Member of research projects nominate:
1. "Improvement of physicochemical characterised to the argillaceous soil";
2. "Improvement of cereals by method of varietal selection in the wilaya of Sidi Bel Abbes".
Fouzia Toumi
Abdelkader Rahmani
Post: Teacher at the University of Djillali Liabes of Sidi Bel Abbès, Faculty of sciences (1997-2007). Scientific degree: Magister of applied ecology science.
Experience: President of scientific club (1993-1998), Engineer in Nature agency (1999-2001), Engineer in Agriculture (2001-2003); responsible of lessons (2003-2007). Scientific research project: Member of biotoxicology laboratory. Member of research projects nominate:
1. "Study of the biodiversity urban and periurbane of the town of Sidi Bel Abbès";
2. "Ecological diagnosis of the liminic sites".
Introduction
Thuya covers about 143,000 hectare [1], this is one of the rare species in Algeria, and it is going to disappear because this useful rustic forest which needs to be given more care is permanently harmed, (cutting -
degradation, fire) [2], its resistant aspect makes it one of the most important and dense species which needs more effective studies.
A wide field of Thuya still dominates the national forest of Tenira which is situated in the mountains of Dhaya. Its superficies counted about 16630 hectare [3] while it
is now only 8800 hectares. The degradation of forest ecosystems is a problem that worries all searchers in general and ecologists in particular. The main cause of this degradation is the antropozoogene pressure: many searchers such as [4-6], [7-9] were interested in studying the causes of the forest ecosystem degradation, both [10] and [11] studies were established in western Algeria.
Fire keeps its dominating pressure with a destructive impact on the Tetraclinaie, which is the only vestige of the Thuya species, it's a warning diminution in which Thuya formations are dealing with. The danger of fire is a notion resulting of the combined action of many factors; we can mention the most important factors responsible of the wide sensitivity of Algerian forests:
- The length of the dry season of summer.
- Structure and nature of the vegetation.
- Frequency of the stormy dry winds
- Uneven relieves.
- Eroded ground which is often over-passing.
- Terrorism taking the forests as a refuge in the 1990, especially in Tenira.
Fire is an important factor that affects the vegetation because of its high frequency; many authors agreed that the successive regression of vegetation is due to it, however, it is necessary to follow the evolution of this vegetation for a period of time either controlling it with an experimental devices or in nature where the vegetation came under fire but in both cases, the exact date of when fire happened must be known [12]. According to him - [12] - the evolution may be done within four ways:
- Checking the different steps of the previous vegetation remaining to a long time.
- The gaps that became more overt than they was before the fire, associated to decreased proportion of ligneous vegetables.
- Instant checking the previous vegetation with no transition.
- Progressive evolution to different vegetations
Presentation of the studied area
Climate and soil The forest of Tenira is 16 km south of Sidi Bel Abbes, 12 km from Teghalimet and 9 km from Boukhanifis; it is crossed by the national road No. 13 linking Sidi Bel Abbes to Telagh.
The forest lies on the secondary Jurassic, relieves are bad enough and formed of porous calcareous layers giving the ground a superficial aspect, the forest lies on superficial enclaved soil between emerged rocks. The superior horizons are constituted of a mixture of sand and calcareous pebbles. The local climate has been realized through two meteorological stations; of Sidi Bel Abbes and of Teghalimet (Table 1). According to [13] the forest of Tenira has a superior semi-arid bio-climate [14].
Table 1
Climatic data of the studied area
Station Altitude, m Rainfall, mm M - m, °C Q2
Sidi Bel Abbès 476 395 33.2 - 1.9 43.2
Teghalimet 650 334 34 - 1 34.8
Tenira
PH 840 468 30.6 - 2.8 57.7
PB 628 393 32.1 - 3.6 47.2
PH: It's the most high point of area. PB: It's the most low point of area.
M: The avearge of maximals temperature of the hot month. m: The avearge of minimals temperature of the cold month.
Vegetation
The forest consisted on a populating of young and old timber-trees of Pinus halepentis Mill and Tetraclinis Articulata Wahl before the fire took place, in under-stages with an average covering of 20 % as a dense high copse. Thuya formed in the particular stationary conditions, pure formations with some vestiges of forest. Quercus Rotundifolia L., it was third in position with a rate of covering of 10 %. The secondary species were especially dominated by Quercus Coccifere L., Phillyrea media L. and Pistacia Lentiscus L. Tetraclinis articulata reached in this forest the treelike stage with an under-wood characteristic of this formation with three different facies: The first one to Rosmarinus tourneforti L. The second to Ampelodesma mauritanica L. The third to Stipa tenacissima L. In spite of a quasi-permanent animal and human pressure, the Thuya formed a plant grouping and dominated the pine of Alep relegating it to secondary specie.
Tetraclinis articulata is present essentially in the form of copse in under-wood of Pinus Halepensis in such conditions the Thuya vegetates and this is what explains its strong density [15]. Tetraclinis articulata presents three facies:
* Ampelodesma when the ground is deep, slightly muddy, in the north and in depressions.
* Rosmarinus when the ground is of type rendzine, strong presence of limestone in the south.
* Stipa in the most extreme conditions [16].
Identification of Tetraclinis articulata
Monographic quality of Tetraclinis articulata
The Thuya of North Africa (Tetraclinis articulata Vahl.) has been defined by (Vahl, 1979) under the name of Thuya articulata, it is one of the spermaphyte gymnosperme branches, belonging to coniferous family [17]. The botanic characters as given by [3] are: the Thuya of Maghreb (North Africa) is resinous with a light foliage,
Международный научный журнал «Альтернативная энергетика и экология» № 5 (61) 2008 © Научно-технический центр «TATA», 2008
particular in the Maghreb countries where its density floats from the east to the west [2]. However [20] consider that Thuya in North Africa covers a surface of million hectares, all the searches that studied this specie: [1, 2, 3, 16, 19, 21-26], and others have agreed that Thuya does not require edaphic factors, it is indifferent to the chemical nature of the substratum, can be found in poorest and dries soils, meanwhile it seems that it prefers more calcareous and deep soils.
(see Fig. 1) when it's still young plant, its port is pyramidal, leaves are reduced to two opposed scales, fruits are like a cubic cone, can be opened by four valves in hot conditions, giving away six seeds, the longevity of Thuya can exceed 400 years, it's reproduction is generally done with rejects or sowing [18].
The Thuya of North Africa is an endemic essence of the southern occidental Mediterranean sea [17, 19], in
Fig. 1. Picture of different parts of Thuya three (Tetraclinis articulata)
It is doted with a faculty of adaptation to different types of bio-climates, hot semi-arid in particular, temperate or subhumid and cool [24], it supports the drought and hot weather conditions but not cool humid weather. Adapted to extreme conditions, the Thuya of the Maghreb can
develop on an annual pluviometric slice of 300 mm, an annual average temperature of 15.2 °C and a minimal temperature of 2 °C, average of the temperatures of the warmest month (M) is 32.5 °C [15], [25-27].
Dendrometric characteristics
Thuya is present, as underlined previously, whether in the form of copse or of timber-tree. Exceptionally, the following dendrometric parameters (density averages, height, diameter and volume) for every type of formation
and for every facies give an outline onto these populating. Small squares m2 among 3 types of formation informing about the dendrometric characteristics of the formations of vegetable as showed in Table 2 [23].
Table 2
Dendrometric characteristic of the Thuya formations
Evaluated parameters Copse Timber-tree
Fl F2 F3 Average Fl F2 F3 Average
Density 1680 1120 510 1100 320 210 130 220
Height in cm 2.60 2.10 1.60 2.10 3.70 2.90 2.30 2.90
Diameter in cm 10 8 6 8 21 16 11 16
Volume in cm 34.20 11.80 2.30 16.10 12.20 2.80 18.60 17.30
F1: Facies of Ampelodesma; F2: Facies of Rosmarinus; F3: Facies of Stipa.
These averages of dendrometric data constitute ecological indicators and inform about the dynamism, the potentialities and the development of this plant grouping threatened in its three facies before the fire destroys them. The obtained results constitute a reference in western Algeria where no work is carried on.
Phyto-ecologic Statements
The floral characterizations of these three facies were recapitulated through three representative average statements of the floral composition of this grouping. The phyto-ecologic description of the forest of Tenira confirms these statements of vegetations for the same period [24] (Table 3).
Table 3
Phyto-ecologic average of facies
Facies Constant species
Ampelodesma Rosmarinus Stipa
1 2 3 1 2 3 1 2 3
2.1 1.1 2.1 1.1 + +
2.2 2.1 2.1 2.1 1.1 1.1 +
+ 1.1 1.1 1.1 2.1 2.2 1.1 2.2 2.2
+ + +
1.1 + 1.1 1.1 1.1 2.2 2.1 2.1 2.2
+ + + 1.1 + 2.1 1.1 1.1
+ 1.1 + + 1.1 1.1
+ 1.1 + + 2.1 1.1 2.1 3.2 2.2
1.1 + 1. 1
+ 1.1
2.2 2.1 2. 2 1.1 1.1 +
+ + 1.1 + + 2.1 1.1
+ + 1.12.2 2.1 2.2 1.1 + 2.1
+
+ 1.1 + 2.1
+ + 1.1 1.1
1.1 + 1.1
+ 1.1 +
Quercus coccifera Phillyrea angustifolia Pistacia lentiscus Cytusus triflorus Cistus villosus Vhamaerops humi Juniperus osycedrus
Differential species
Stipa tenacissima Arbutus unedo Genista quadriflora Ampelodesma Mauritanicum Globularia alypum Rosmarinus tournefortii
Campaign species
Astragalus lusitanicus
Asphodelus
Microcarpus
Elichrysum stoechas
Helanthemum
Halimifoliums
Международный научный журнал «Альтернативная энергетика и экология» № 5 (61) 2008 © Научно-технический центр «TATA», 2008
Materials and methods
The objective of this work is follow the dynamism of Tetraclinis atriculata after the 1991 fire that affected most of our forests (the case of Tenira forest in this study), this dynamism needs a long period of time to obtain satisfactory results, concerning the regeneration, development and their comparison with other neighbourhood species.
As we have seen previously, the Tetraclinetum is affected with human and animal alterations, it became more fragile after being affected by fire in 1991, due to terrorism who took the forest as a refuge. This vital plant grouping for a perpetuity of the vegetable cover in semi-arid conditions, its capacities of rejecting and to colonize space every time it is destroyed needs to be protected.
The work will be methodologically based on observing Thuya in the forests of Tenira (western Algeria) after it was destroyed by fire and to know its behaviour, these observations will be taken in a period of 15 years along, with a periodicity of 5 years in which we will determine the number of stalks, as well as the height and diameter of two formations which are (timber-tree and copse) and
Dendrometric parameter 5 years
then of three identified facies: F1, F2, F3, then we will determine the annual increase of height and diameter taking into account their age.
The observations of 15 years from 1991 to 2006 took place some months after the fire of 1991, with a periodicity of 5 years, which means three measures concerning:
- The number of copses by hectare.
- The number of stalks by copse by hectare.
- The average diameter of stalks.
- The height averages stalks.
Obtained results
Three years after fire took place, Thuya started rejecting and colonizing destroyed spaces, after some floral sorts of its procession The dendrometric parameters measured after five years on small squares of 100 m2 and those measured after ten years and fifteen years began to give refusals and to colonize the space as shown in Table 4, 5 and 6 respectively. Table 7 constitutes the global result of our study, and then we have to underline annual growth average in height, and in diameter of this specie.
Table 4
er fire on small squares of 100 m2
Evaluated parameters Copse Timber-tree
F1 F2 F3 Average F1 F2 F3 Average
Number of copse 530 460 290 426 310 260 160 243
Number of stalks of copse 2120 1380 870 1456 1550 1300 960 1270
Height average of stalks in cm 55 48 37 46. 6 83 76 65 74.6
Diameter average of stalks in cm 2.8 2.1 1.8 2.2 4.3 3.5 2.2 3.3
Annual growth average in height 11.0 9.6 7.0 9.3 16.6 15.2 13.0 14.9
Annual growth average in diameter 0.5 0.4 0.30 0.4 0.8 0.7 0.4 0.6
F1: Facies of Ampelodesma; F2: Facies of Rosmarinus; F3: Facies of Stipa.
Table 5
Measure of dendrometric parameters ten years after fire done on the same small squares of 100 m2
Evaluated parameters Copse Timber-tree
F1 F2 F3 Average F1 F2 F3 Average
Number of copse 510 430 270 403 290 230 140 220
Number of stalks of copse 2550 1290 1620 1820 1740 1150 840 1343
Height average of stalks in cm 112 103 81 98.6 178 157 137 157.3
Diameter average of stalks in cm 4.9 4.6 4.1 4.5 5.1 4.9 4.3 4.7
Annual growth average in height 11.2 10.3 0.8 9.8 17.8 15.7 13.7 15.7
Annual growth average in diameter 0.49 0.46 0.41 0.45 0.51 0.49 0.43 0.4
International Scientific Journal for Alternative Energy and Ecology № 5 (61) 2008
© Scientific Technical Centre «TATA», 2008
Table 6
Dendrometric parameter 15 years after fire
Evaluated parameters Copse Timber-tree
F1 F2 F3 Average F1 F2 F3 Average
Number of copse 510 420 250 393 280 230 120 210
Number of stalks of copse 2040 1260 1000 1433 840 920 480 746
Height average of stalks in cm 162 145 98 135 251 237 214 234
Diameter average of stalks in cm 6.7 6.2 5.8 6.2 7.3 6.8 6.1 6.7
Annual growth average in height 10.8 9.6 6.5 9.0 16.7 15.8 14.3 15.0
Annual growth average in diameter 0.4 0.4 0.3 0.45 0.4 0.4 0.4 0.4
Table 7
Annual growth average in height and in diameter
Growth average in cm Under copse Under timber-tree
Age, years 5 10 15 5 10 15
Height 9.3 9.8 9.0 14.9 15.7 15.0
Diameter 0.4 0.45 0.45 0.6 0.4 0.4
The obtained results over a relatively short period are interesting and allow appreciating the evolution of Thuya after fire destroyed the formation of copse and forest. The data obtained by stuffed and by type of formation help to better understand the dynamics of this plant grouping.
Synthesis and interpretation of the results
Five years after fire, the regeneration is strongly present but the dominant sort is not Tetraclinis articulata, because its increase in height is weak compared with the other sorts affected by the fire as Phillyrea, Pistacia, Cistus.
The annual average increase both in height and in diameter remains considerable compared with other species often used in reforestations. The forest where Thuya was destroyed by fire presents a lower regeneration than that of the copse which is 15 %. Ten years after fire, the registered differences are constant and the average increases both in height and in diameter remain rather stable. The same observations would be made on the results obtained 15 years after fire.
15 years after fire of the copse of Thuya, stalks stemming from refusal among 1433 present an average height of 135 cm and an average diameter of 6.2 cm while in forest, the averages are sharply superior, the height is 234 cm while the diameter is 6.7 cm and the number of stalks is 746. The growth in height and in diameter remains superior to 30 % in the results obtained in the destroyed copse.
The annual average growth in height and in diameter of all Thuya facies is recapitulated in the Table 7. The growth in height remains sharply superior for the developing forest after fire. They are 9 cm for the copse and 15 cm for the young forest. The density or the number of stalk by hectare constitutes a determining parameter in the growth average especially in height. The growth remains relatively stable for the diameter no matter what conditions of the destroyed vegetable formation are.
The increases both in height and in diameter and under three fancies and type of formation (copse or timbertree) affected by fire remain slightly lower than those of other species considered as fast growing in semi-arid floor and which remain widely used in Algeria. In this range we can mention Pinus Halepensis Mill. Quercus ilex L, Pinus pinaster L.
Comparison with other species After fire, growth in height and in diameter are respectively estimated at 9.3 cm and 0.4 cm: for the pine of Alep (the most used specie in reforestation and afforestation and repopulation) under bioclimatic semiarid conditions, the floor the average increases in height and in diameter and is estimated for the first one between 14 and 18 cm and for the second between 1 and 2 cm. Analyzing the development in height and in diameter of the Pinus halepinsis of 13-year-old in the green dam [28], advance an annual average growth of 0.2 cm in diameter and 17 cm in height.
Conclusion
The fire does not seem to modify in any important way the floral composition the vegetable training formations of Tetraclinis articulata. It is competed by species with strong power of covering as Pistacia lentiscus, Quercus coccifera, Phillyrea angustifolia, Rosmarinus tourneforti, Thuya, with its small domination of space starts again slowly but certainly its colonizing area. Thuya, after fire develops and to reconstitute its plant grouping in all climatic, edaphic, and antropozoogene pressure conditions.
Международный научный журнал «Альтернативная энергетика и экология» № 5 (61) 2008 © Научно-технический центр «TATA», 2008
The results of growth in height and in diameter obtained under three facies of Thuya confirm the resistance of this specie to changes in general and fires in particular. Annual growth average in height and in diameter oscillates respectively between 9.3 and 15.7 cm for the first parameter and between 0.4 and 0.6 cm for the second.
The hasty condemnation of which Thuya was the subject, imputed to its very slow growth, seems to be wondering by comparing the results obtained after fire to other species. The difference is not important, the faculty of refusal and resistance of Thuya often militates in favour of this relegated specie giving a second plan in all repopulations and reforestations.
References
1. Letreuch Belarouci N. Reafforestations in Algeria and their future prospects O. P. U. 1991. Vol. l. P. 294.
2. Benabdeli K. Thuya: a disappearing noble essence, issue Al-Ardh. 1992. No. 20: P. 38-42.
3. Boudy. North African forest Economy. Tome I: monography and forest essence treatment, Paris, 1950. P. 483.
4. Gaussen H. Conifer of North Africa, ecology and reafforestation. Issue of Applied Botany. 1952. P. 361362, 504-532.
5. Ruellan A. The role of the climate, and the rocks in the repartition of soils, in Moulaya hills. (Morocco), 1965. P. 2386.
6. Decourt N. Primary Production, useful production: methods of evaluation, fire of production. Forest annals. 1973. No. 30. 219-238.
7. Gaouar A. Hypothesis and reflection on forest ecosystem degradations, in the area of Tlemcen. Forest Med, 1980. No. 2. P. 131-146.
8. Gaouar A. Forest ecosystem degradation and development conceptions, university of Oran. 1980 b, 19. P. 151-163.
9. Pouget M. Soil - vegetation relationship in the area of Algiers. PHD thesis - ORTOM - Paris. 1980. P. 555.
10. Dahmani M. Contribution To the studies of Quercus ilex, in Tlemcen Mountains (west of Algeria). Phyto-ecologic and phytosociologic approach. PHD thesis, university of Algiers. 1984. P. 286.
11. Djelouli Y. et al. Climate and flora in the south west of Algeria. Bull. Soc. Bot. Fr 134, 1987. P.376-384.
12. Trabaud. Biologic and ecologic impact of fire on organizations, the structure and the evolution of vegetation the area of Gaigues of Bas-Langue. PHD thesis. 1980. P. 208.
13. Stewart P.H. Pluviometric quotient and bio aspheric degradation: some reflections// Bull. Soc. Nat. Afr. North. Alger. 1969. P 23-26.
14. Benouda Z. Phytoecologic and edaphic diagnostic and the establishment of a soil-vegetation relationship in the forests of: Touazizine - Khoudida - Tenira. 1994.
15. Kadik B. Contributions in the study of the pine of Alep (Pinus halfpennies Mill) in Algeria: dendrometric and morphology ecology. O. P. U, Algiers. 1987. P. 575.
16. Letreuch Belarouci, N. Reflection around forest development. (Zones with potential of production). O. P. U. Algiers. 1995. P. 51.
17. Quezel P. Biogeography and ecology of conifers in the Mediterranean surrounding - forest ecology. GAUTHIER-VILLARS. 1981. P. 205-255.
18. Maatoug M. Effects of factors stational on the mechanical physical properties and the paper-maker of the wood of Thuya-the Maghreb. Thesis of a doctorate University of Sidi Bel Abbes; 2003. P. 140.
19. Benabid A. Ecologic, phytososiologic and sylvopastoral study of Tetraclinaie in Amsittene, PHD thesis, university of Aix-Marseille. 1976.
20. Bachoua and Voreux C.H. Tetraclinaie adjustment in Amsitteme (Morocco) ENGREF, Nancy. 1986. P. 12.
21. Treep L. The choice of species. Paris, 1976. P. 195.
22. Alcaraz C. vegetation of western Algeria, PHD thesis, university of Perpignan. 1982. P. 415.
23. Letreuch Belarouci. N. Dendrometry: estimation methods of the stational productivity. Photocopied, institute of Forestry of Tlemcen. 1994. P. 70.
24. Benabdeli K. Introduction to Algerian forest politics. Scientific open-day of ONTF. Oran. 1976. P. 25.
25. Benabdeli K. Physiognomic, structural and dynamic aspect of forest ecosystems facing anthropozoogene pressure in the mountains near Tlemcen and Dhaya mountains (Western Algeria), PHD thesis, university of Sidi Bel Abbes. 1996. P. 356
26. Boudy P. Forest guide in North Africa, edition maison rustique. 1952.
27. Quezel P. Biogeography and ecology of conifers in the Mediterranean surrounding - forest ecology. 1980.
28. Benabdeli K. First dendrometrics results of the pine of Alep plantations (Pinus HalepensisMill.) in the Green dam (Zone of Aflou, Algeria). Ecologia mediterranea. 1998. No. 24 (1). P. 43-51.
International Scientific Journal for Alternative Energy and Ecology № 5 (61) 2008
© Scientific Technical Centre «TATA», 2008
