INTRODUCTION
Ôanliurfa is situated in the south-east of Turkey (Fig. 2). Şanliurfa extended 36 41’ 28’= N latitude with 37 57’ 50’= N latitude and between 37 49’ 12’= E longitude with 40 10’ E longitude. The altitude of the area changes between 350-1200 m. The climate is cold and rainy in winter, hot and dry in summer. The economy of the province currently depends upon export demand. Its cultivable land is used mostly to grow cereals. Wheat is the main crop followed by barley and lentil (Anonymous, 2000). There is also chickpea farming and pistachio culture. Its industrial crops and cotton are sesame (Fig. 1).
Ôanliurfa has characteristic Irano-Turanian flora with some Mediterranean
elements also. The most common woody species in the vegetation as follows: Eleagnus
angustufolia, Prunus amygdalus, Platanus orientalis, Juglans
regia, Betula pendula, Amygdalus arabica, Fraxinus angustifolia
subsp. syriaca, Celtis tournefortii, Crataegus aronia,
Cornus mas, Morus alba, Paliurus spina-christi,
R. canina, Astragalus spp., Olea europaea, Pistacia khinjuk,
P. terebinthus, P. vera, Quercus infectoria, Q. brantii,
Ficus carica and Populus euphratica.
|
| Fig. 1: | Ombrothermic
diagram of Şanliurfa, Turkey |
Like as forests, desert, semi desert, pasture and phrygana, steppe vegetation
is widespread in Şanliurfa’s plant cover (Zohary, 1973; Türkmen
et al., 2005). 75.5% of Şanliurfa’s land which is 18.584 km2
is steppes spreading from 400 to 2000 m. Mostly in South and South-East side
steppes, xerophytic species of Artermisia, Stipa, Botryochloa, Koeleria,
Thymus, Astragalus, Ziziphora genus are dominant. This lands are rich
of CaCO3. Yearly rainfall is between 400-450 mm (Anonymous, 2004).
Semiarid mediterranean climate occurs in research area. According to Emberger the precipitation-temperature coefficient Q) is 42.94 (Akman, 1990). Annual mean temperature is 18.7°C. The maximum mean temperature (M) is 46.8°C, in July. The minimum mean tempereature (m) is -6.8°C, in February. Annual rainfall is about 457.8 mm (Anonymous, 2004) and the seasonal precipitation regime is Winter, Spring, Autumn and Summer. This is the first variant of the East Mediterranean precipitation regime. The ombrothermic diagram shows dry and rainy period (Fig. 1).
Especially, 463 species are with deflowers, 173 species are with monocotyledones. Angyosperms form 98.2% of steppe flora. According to the investigation results, 798 (14.4%) species in Turkey’s flora, which his represented with 4500 species, form the floristic composition of steppe vegetation (Atamov et al., 1996; Atamov et al., 1998). Poaceae, Asteraceae, Lamiaceae, Fabaceae, Liliaceae can be listed as the most important families of vegetation (Davis, 1965-1985).
Since, of steppe the vegetation is in different elevations from sea, their ecological environments is different and this coursed to differences in their floristic composition and differences in their phytosenologic structure. Regarding to this, Şanliurfa’s steppe vegetation is divided into four phytosenotypes.1; Main steppes 2; Xerophyte shrubs steppes 3; Semideserted steppes 4; Mountain kriophyl steppes.
The investigation of some kinds of phytocenose phytomass, with vertical distribution
and properties of fractions of phytocenose phytomass enable to determine the
importance of phytocenose phytomass in vertical structure of vegetation (Sukacov,
1972). Elaborately investigated layering of forest phytocenoses. Phytomass distribution
of plants in phytocenoses on the ground and underground is one of the seasonally
important elements. Except forests in grassland, especially steppe of the phytocenoses
layering is difficult to distinguish. For example, biomorphs, one of the steppe
phytocenoses and their morphological characteristics don’t show as very
certain differences as they do in forests. Vertical structure and phytomass
of the steppe phytocenoses hod been investigated and well understood by the
researchers: (Dokman, 1960; Şhalit, 1960; Makarova and Fartushina, 1972;
Korneyeva, 1974; Semyonova-Tyan Şanskaya 1977; Sims and Singh, 1978; Danilov,
1983; Rabotnov, 1983; Lebedeva, 1984; Atamov, 2000; Atamov, 2001; Titliyanova,
1977; Bazileviç et al., 1988), in this proposed research, suggest
that the consecutive investigations for formation steps of one layering and
every vegetation term of any phytosenoses should be investigated to determine
the distribution of phytomass on layers.
It is quitted difficult to place every plants of steppe phytocenoses into an certain layers by measuring optimum length of plants. Mostly, structures of some species that are rare in phytocenoses and phytocenologic role are ignored. For example, in the steppe vegetation of Şanliurfa Colchicum cilicium (Boiss.). Dammer, Colchicum persicum Baker, Vicia cordata Wulf., V. hybrida L. etc. have important role in the structure of phytocenoses in autumn.
Therefore, in the duration of vegetation common observable cover of phytocenoses and species, separately, need measuring more than once. This type of measuring enables to understand. Formation of vertical structure of vegetative organs in different species and phytomass dynamics of vegetation in different seasons. In addition to investigate the analytic relations of phytomass structure to vertical structure in steppe phytocenoses, investigations of separately dominant species and agrobotanic fractions, such as cereals, legumen and some grasses, for their productivity in layers are absolutely needed. As a result, this type of investigations will explicitly clarify the role of separately dominant species and agrobotanical fractions in the formation of vertical structure of steppe phytocenoses.
Similar analytic studies are important in terms of investigation of vertical structure of underground steppe vegetation (Şalit, 1960; Salit, 1958-1960; Makarova and Fartuşina, 1972; Sims and Singh, 1978; Danilova, 1983; Lapinskine, 1986; Atamov, 2001).
MATERIALS AND METHODS
The distribution of vertical and structure of steppe pytocenoses in Şanliurfa
were studied for the dominant formations, namely Artemisia herba albae-Teucrietum
poliae ass.nova, Thymo loucicaulisae-Phlomisetum kurdiae ass.nova
and Astragalo lamarki-Stipetum holocericeae ass.nova (Braun-Blanquet,
1965; Weber, 2000) in steppes of Tektek mountain, Fatik mountain, Birecik dam
arae, Karkamiş dam area, Mezra and Ceylanpinar State Farm similar destinations
during 2002-2005. Between 2002-2005, once a month, research tours have been
organized to Tektek mountain, Fatik mountain, Birecik and Mezra and Ceylanpinar
State Farm. These regions are important geobotanical regions. Research materials
include Artemiso herba albae-Teucrietum poliae ass.nova, Thymo loucicaulisae-Phlomisetum
kurdiae ass.nova and Astragalo lamarki-Stipetum holocericeae ass.
nova which are widespread in steppe formations in these regions (Fig.
2).
|
| Fig. 2: | Map
of the territory studied. Dashed curve specifies the territory, Which
was intensively studied. Distribution of the respective communities according
to the releve/ date is given |
The structure of phytomass fraction has been studied as annual green phytomass(G),
over soil dried phytomass (D), dried-litter phytomass(L), subsoil dead phytomass
in soil(R), total dead subsoil phytomass (D+L+V), dead subsoil phytomass(V),
total phytomass (G+R+D+L+V). Those parameters, as products of herbaceous ecosystems,
have been studied according the bu methods (Vagina and Şatochina, 1976;
Bazilevic et al., 1988) but subsoil phytomass has been studied according
to the method by according to (Şhalit, 1958-1960; Lapinskine, 1986). Over
soil phytomass in 1 m2 and subsoil phytomass in 0.25 m2,
5 times a month, were studied in Artemiso herba albae-Teucerietum poliae
ass. nova, Thymo loucicaulisae-Phlomisetum kurdiae ass.nova and Astragalo
lamarki-Stipetum holocericeae ass. nova formations. Obtained results have
been evaluated statistically (Lakin, 1973).
The researched species are very common in the research destinations at the elevations of 400-1200 m. The coldest month in the years was January and average monthly temperature ranges from 3.2 to 6.5°C, while the hottest month in the years is July and monthly temperature ranges from 32.4 to 39.4°C. Because rainfall events in Gobustan is lower that 34% of yearly evaporation summers are always dry. Rainfall events are very common in winter and fall. The yearly rainfall amount is between 316.5-458 mm in the region. The more the climate is cold and most, the more the climate is dry and hot in Tektek mountain and Fatik mountain (Anonymous, 2004).
Korcagina used conduct the research (Korcagina, 1976). The three formations of Artemiso herba albae-Teucrietum poliae ass.nova, Thymo loucicaulisae-Phlomisetum kurdiae ass.nova and Astragalo lamarki-Stipetum holocericeae ass.nova were investigated and measured in plots of 100 m2 size. Three measuring per month for each phenophase for each species in phytocenoses were done and 5 year results were obtained. Similarly, ground and underground phytomass in each layer of 10 cm thickness of soil were determined. These measuring was performed with 10 replications in 1 m2 plots for phytomass on the ground and in 50 cm2 plots for underground phytomass. The sampled grass mass on the surface soil was fractionated as cereals, legumes and other grasses.
RESULTS AND DISCUSSION
Subsoil and over soil phytomass change according to steppe phytosenotypes and
spread regions. This variation is seen according to meteorological conditions
of the year especially when it rains. Depends on the steppe phytocenotypes,
seasonal changes in climate properties separated from each other definitely.
As a result, plant is exposed to unclosed moisture depression. This depression
is high especially in deserted steppes but as it decreases in germinated Graminea
main steppes and xerophytic bushed middle mountain steppes it decreases more
in high mountain kriophyle pasture. This variation shows it in phytasenologic
properties as well as in subsoil and over soil phytomass of vegetation (Table
1).
As shown in Table 3 change ratio of over soil phytomass is different in various steppe phytosenotypes but this ratio is close in shrub mountain steppes (13.5-28.7 sent ha-1) and main stapes (12.6-24 sent ha-1). This similarity is also seen in undersoil phytomass (225.0-450.0 and 219.7-473.0 sent ha-1). However, when looked at quantities, this is a similarity between deserted steppes and kriophyle shrub steppes but this similarity is only at the base of quantity. The content of components of phytomass is definitely different. As total change of phytomass in Şanliurfa’s steppe vegetation is restricted about 40.9-497.0 sent ha-1.
In 2002-2005, according to seasons, between March-October, seasonal dynamic
of green mass, dried over soil phytomass, dried- litter over soil phytomass,
dead phytomass and general over soil phytomass in Artemiso herba albae-Teueritum
poliae ass.nova, Thymo loucicaulisae-Phlomisetum kurdiae ass.nova
and Astragalo lamarki-Stipetum holocericeae ass.nova formations are given
in Table 4. As seen in the Table, these parameters change
according to seasons and formations. In Thymo loucicaulisae-Phlomisetum kurdiae
ass.nova formation, phytomass of separate fractions are more than other
two formations (Artemiso herba albae-Teucrietum poliae ass.nova and
Astragalo lamarki-Stipetum holocericeae ass.nova). There for, in Thymo
loucicaulisae-Phlomisetum kurdiae ass.nova, over soil green mass (G) 2.8-18.9
sent ha-1 in Astragalo lamarki-Stipetum holocericeae ass.nova
1.2-14.9 sent ha-1, in Artemiso herba albae-Teueritum poliae
ass. nova 1.5-13.8 sent ha-1, appraise about these values (Fig.
3). As shown in Fig. 3 in each three formations, green
phytomass begins from March shows a clear increase and shows maximum increase
at the end of may and middle of June. In the fallowing months it decreases and
it is minimum in November. The reasons for this increase are high temperature
humidity in the soil, this factor give convenient environment to plants which
are in efermose 2. Amount of green phytomass and dynamic properties of Thymo
loucicaulisae-Phlomisetum kurdiae ass.nova and Artemiso herba albae-Teueritum
poliae ass.nova are close to each other but they are different from Artemiso
herba albae-Teucrietum poliae ass.nova. As seen in Table
4, Thymo loucicaulisae-Phlomisetum kurdiae ass.nova the amount of
phytomass (D) which dried but not separated from plant is higher and it is at
the border of 0.6-9.1 sent ha-1 but it changes at the border of 0.3-
6.3 sent ha-1 in Artemiso herba albae-Teucrietum poliae ass.nova.
In each three formations, from the beginning of Marc to middle of June there
is a gradual increase but from the middle of summer it increase gradually and
it reaches the maximum value in the beginning of Autumn (Fig.
3).
| Table 1: | Quantities
of total phytomass, over soil phytomass and subsoil phytomass in Şanliurfa
steppe vegetation |
 |
*-sent
= 100 kg, ha = hectare |
|
| Fig. 3: | Seasonal
dynamics of green phytomass elation |
In investigated steppe formations, quantity of phytomass. Fraction (C) of dried
litter plant leftovers in Thymo loucicaulisae-Phlomisetum kurdiae ass.nova
changes between 2.3-8.7 sent ha-1, in Artemiso herba albae-Teucrietum
poliae ass.nova between 1.4-5.8 sent ha-1 in Astragalo lamarki-Stipetum
holocericeae ass.nova between 1.5-5.3 sent ha-1 (Table
2).
In each three formations, seasonal change of dynamic of L decreases from the beginning of Marc to middle of summer gradually but later it increases until middle of Autumn (Fig. 5). This increases, in general is related to increased green phytomass in this period and dried over soil parts of efomerosez and efomeroseoid species which completed their short life period, that is, quantity of green phytomass and quantity of dried-litter phytomass have right ratio (Fig. 3-5). While seasonal dynamic of g changes Conversely in this case, in the maximum period of G, D and L are maximum valves G is minimum (Fig. 3-5).
D and L are separated fraction of dead over soil phytomass and their seasonal
total change is at the border of 2.9-17.3 sent ha-1 in Thymo loucicaulisae-Phlomisetum
kurdiae ass.nova, 2.3-10.3 sent ha-1 in Artemiso herba albae-Teucrietum
poliae ass.nova, 1.8-11.0 sent ha-1 in Astragalo lamarki-Stipetum
holocericeae ass.nova (Table 4). As seasonal change D+L
decreases from beginning of March until middle of summer but later it reaches
the maximum at the beginning of October (Fig. 6).
| Table 2: | Seasonal
dynamics of phytomass of green (G), dried (D) and dried-letter (L) in
Artemiso herba albae-Teucrietum poliae ass.nova (I), Thymo loucicaulisae-Phlomisetum
kurdiae ass.nova (II) and Astragalo lamarki-Stipetum holocericeae
ass.nova (III) formations |
 |
| Table 3: | Annual
dynamics of plant phytomass in germinated main steppes (Graminetum) |
 |
|
| Fig. 4: | Seasonal
dynamic of dried phytomass (D) in steppe vegetation |
Total green mass (G) and dried mass (D+L) give the general oversoil phytomass
(G+D+L) (Fig. 7). In investigated each formation, seasonal
change of G+D+L is minimum at beginning of spring and it is maximum at the lend
of summer and at the beginning of Autumn. G+D+L change at the border of 8.3-30.9
sent ha-1 in Thymo loucicaulisae-Phlomisetum kurdiae ass.nova,
6.3-17.6 sent ha-1 in Artemiso herba albae-Teucrietum poliae ass.nova
and 6.9-21.3 sent ha-1 in Astragalo lamarki-Stipetum holocericeae
ass.nova Seasonal dynamic of this change is given in Fig.
5. In each three formation, G+D+L increases from beginning of Spring until
June.
|
| Fig. 5: | Seasonal
dynamic of dried-litter phytomass (L) in steppe vegetation |
A stagnation is observed during July. Later, a decrease is seen from October.
From the point of were of phytomass, Thymo loucicaulisae-Phlomisetum kurdiae
ass.nova has more phytomass with respect to other two formations.
In addition to parameters (G,D,L) which have been shown since 2000, in subsoil phytomass, annual rust system, live(R) and dead (V) mass of root were investigated. In 1991-1998, change of dynamic was analyzed in formations and average values were found and these are given in Table 3.
As shown in Table 3, these parameters show changeability in some years. The important factor causing this changeability is that 2001-2002 years were rainless.
| Table 4: | Annual(2001-2005)
quantity (g/m2) change of phytomass in steppe vegetation |
 |
|
| Fig. 6: | Seasonal
dynamic of dried phytomass (D+L) in steppe vegetation |
|
| Fig. 7: | Seasonal
dynamics of over soil phytomass (G+D+L) in steppe vegetation |
Therefore, in steppe vegetation phytomass is minimum, but in 2001, 2004 and 2005 abundant rainfall caused an increase in phytomass. The results obtained in 4 year period of investigation are taken and properties of structure of phytomass fraction for Şanliurfa’s steppe vegetation were determined (Fig. 8).
Parameters (G+D+L+R+V) shown were studied separately in steppe phytosenotypes in 2000-2004, in deserted steppes (Artemiso-herba-albae-Linetum microfilae formations), in germinated Graminea main steppes (Stipetum holoseriserae), in middle mountain xeserophytic shrubs steppes (Thymo-Astragaletum strictifoliae) and high mountain kriophyle pasture steppes (Astragaletum lamarkiae) (Table 6). These parameters change according to the type of phytosenotypes of steppes. The general highest phytomass of these phytosenotypes gradually is in middle mountain shrub xerophytic steppes (Thymeto-longicaulisae) and then high mountain kriophyte pasture steppes (Stipetum holosericeae) and at the last in deserted steppe (Artemiso herba-albae-Linetum microfilae ) (Table 4).
Nual change of dynamic of these parameters (G,D+L,R,V) and change of each parameters show similarity in respect of years (Fig. 9). According to this, the amount of in comparison with the amount of V decreases in each formation of phytosenotype with respect to formations. İncrease in these parameters is according to the following sequence; Artemisio herba-alba-Linetum microphilae < Astragala lamarkiae-Thymbra spicatae < Stipetum holoseriseraeTeucrium-poliae < Thymo lancicaulisae-Teucrietum poliae In 2000-2004, the range limit of these parameters valuated to formations is between G-4.2-18.3 g m-2; D+L 10.3-22.6 g m-2; R-458-1477 g m-2; V-362-1156 g m-2 (Table 4 and Fig. 9).
As a result, due soil and subsoil phytomass of steppe vegetation change according
to meteorological condition of the year. Change between 5.0-28.7 sent ha-1
and subsoil phytomass change between 40.9-497.0 sent ha-1 values.
Green phytomass (G) begins from March increases continuously until end of May
and it reaches its maximum level later it decreases gradually until the end
of September. Dried phytomass (D) reduced from March until end of June but later
it increases gradually and it reaches its maximum level at the beginning of
November. Dried-litter phytomass (L) reduced gradually. From March until June
but later it shows an increase until November- D+L are dead phytomass and they
are added to formation of soil. As seasonal, D+L decrease from March until June
but later they reaches the maximum level. Subsoil phytomass and their ratio
change from 1:11 to 1:37.
|
| Fig. 8: | The
seasonal change in height of important species in Stipeto-varioherbosum
formation |
|
| Fig. 9: | (Fraction,
A-Various grasses) The vertical distribution of the over soil general
phytomass in formations of fraction |
|
| Fig. 10: | The
vertical distribution of the sub soil general phytomass in formations
of fraction |
|
| Fig. 11: | The
vertical fractional distribution of the soil general phytomass in formations
of fraction |
The ratio of phytomass of subsoil and over soil were low(1:4 to 1:8) in the
wet years (2001, 2002, 2005,) and high in dry year (2003, 2004). Due to grazing
and lawning, for both in drought and wet years, the ratio has decreased Atamov
(2004).
Vertical distribution of surface and subsurface soil phytomass fractions and
distribution of hygroscopic moisture in surface soil phytomass are registered
as in the Fig. 8-12.
Figure 12A-C The vertical fractional
distribution of higroscopic water in over soil phytomass of steppe vegetation
(Fraction A. Graminea B. Various herbs C. Fabaceae).
| Table 5: | The
vertical fractional distribution of hygroscopic water in overground phytomass
of Şanliurfa’s dominant formations of steppe vegetation |
 |
|
| Fig. 12A: |
The vertical fractional distribution of higroscopic water
in over soil phytomass of steppe vegetation |
|
| Fig. 12B: |
The vertical fractional distribution of higroscopic water
in over soil phytomass of steppe vegetation |
These results suggest that the roles of different agrobotanical fractions in
constituting the productivity in steppe phytocenoses enable and direct the researcher
to make an elaborately explicitly and scientifically essential multiple categorization
of a phytocenoses.
|
| Fig. 12C: |
The vertical fractional distribution of higroscopic water
in over soil phytomass of steppe vegetation |
On the stems of the most species in steppe vegetation leaves are set 10-30
cm above the ground. The rots harbour boring generative organs are set higher
than 10-30 cm on the stem. In our former research, we separated plant species
in a range of consecutive categories of heights. In terms of their height dominant
plants groups, determined by the number of individuals of similar heights. In
terms of their height dominant plant groups, determined by the number of individuals
of similar height from the each species different from the rest of the plant
population.
As shown in Fig. 6-10 the height of most of the plants in steppe phytocenoses of Azerbaijan is restricted due to moisture content and elevation of the land. Therefore, the most important physiologic body of the plant is in deeper soil profile rather than upper soil layer. However, vertical structure and distribution of phytomass in phytocenoses of the steppe vegetation is simpler than in the others. In temperature and moisture deficit conditions layering due to different height of individuals of plants in inter-layers increase.
During the vegetation period, vertical and horizontal distribution of phytomass and changes in physiologically active organs of a general plant group and its various species always because of the changes in botanical composition of the plants. Vertical structure of grass covers of Şanliurfa and therefore phytomass of steppe vegetation vary in very large extent in a year. Vertical structure of phytomass in steppe vegetation is determined by morphologic and biologic characteristics of the dominant species and composition of phytosenoses. These characteristics are strongly related to climate and soil conditions in the seasons of a year (Table 5).
In all of the three formations, the amount of phytomass of subsoil (547.5-1182.5 g m-2) and over soil (126.6-235.8 g m-2), respectively, was chanced depending on soil type and its moisture characteristics. Artemiso herba albae-Teueritum poliae ass.nova, Thymo loucicaulisae-Phlomisetum kurdiae ass.nova and Astragalo lamarki-Stipetum holocericeae ass.nova In the researched formations, distribution of vertical fraction of hygroscopic water in phytomass, over soil was investigated. For the three formations, in the leaves of cereals fractions the hygroscopic water content was 31.9-54.1 and 40.9-63.2% for various grasses. For the fractions from cereals, maximum hygroscopic water amount in three formations of species was between 52.0 and 51.4%. This amount of water was contained in second layer (10-20 cm) of phytocenoses. For various grasses of Artemiso herba albae-Teucrietum poliae ass.nova, Thymo loucicaulisae-Phlomisetum kurdiae ass.nova and Astragalo lamarki-Stipetum holocericeae ass.nova, the water content was 54.6, 59.6 and 62.7%, respectively. In Astragalo lamarki-Stipetum holocericeae ass. nova formation maximum moisture was contained in second layer (30-40 cm) (Fig. 11). Moisture contend increased from 10 cm depth through 40 cm depth in the soil. This increase is directly proportional to vegetative and generative organs growing in there phytomass of over soil and vertical fraction distribution of leaves.
Moisture content in grass cover, especially vertical distribution of moisture content in steppe vegetation is strongly related to fraction distribution of phytomass due to its roles in structure of agrobotanic fraction and vertical phytocenologic structure of cenose.
The investigation of vertical structure of steppe phytomass and vertical fraction
distribution is very important to find the way to use vegetation areas more
productive to evaluate their land use planning. For example, if the large amount
of phytomass of Festuceto- varioherbosum places the lowest layer.
These type areas are suggested to use as graze lands, while Artemiso herba
albae-Teueritum poliae ass.nova, Thymo loucicaulisae-Phlomisetum kurdiae
ass.nova and Astragalo lamarki-Stipetum holocericeae ass.nova have
vertical pytomass in the uppest layer, the areas occupied by these formations
should be used as lawn lands.
The maximum amount of phytomass over soil is contained in 10-30 cm layer, while the maximum is included in 40-50 cm layer over the soil. The amount of subsoil phytomass decreases as the soil depth. Hygroscopic water content of phytomass in over soil varies in relation to vertical fraction distribution of the phytomass.
This variation depends on, especially in various grasses, the ratio of phytomass of agrobotanic groups to each other, the amount of vegetative and generative fractions and their locations in the layers.
ACKNOWLEDGMENT
We are grateful to the Research Fund of Harran University for financial support (Project No: 294). Special thanks also go to the personnel of Şanliurfa Agricultural Administrative.
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