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To assess the state of coenopopulations of rare and endemic plants, it is important to evaluate the age index, efficiency index, and delta-omega analysis. For this, we studied the age composition of six coenopopulations of Lipskya insignis (Apiaceae) located in the south of the Republic of Uzbekistan. The results showed that in all studied coenopopulations generative individuals prevail, the number of which in most cases is more than half of the total. The calculation of the age index showed that the state of all coenopopulations is mature. Delta-omega analysis also confirmed the result, and deviations were observed only in hundredths of an age index.
Introduction
The southern regions of Uzbekistan have a diverse relief, which includes both desert and alpine regions. Therefore, despite the arid conditions, a wide variety of plants can be found here. Among them, there are poorly studied and endemic species that are very popular among the local population.
Lipskya insignis (Apiaceae) is one of such endemic species of the Pamir-Alai, which has a strong specific smell and is used as a spicy plant. This is a perennial polycarpic herbaceous plant with a torn area. The altitude range of growth is quite narrow – from 800 to 1300 m.
The generative shoot is monocarpic, 30–40 cm high, most often having branches of the 1st and 2nd order, rarely 3rd order. The rod-shaped root, extending to a depth of 1 m, is at the same time a place of storage of nutrients. The neck is thickened due to the lamellar remains of dead basal leaves. Leaves of a generative shoot are sessile, basal leaves on long petioles. The flowers are small, white, collected in a complex umbrella. Central flowers are bisexual, sessile or with short pedicels, the uttermost flowers are male, on long pedicels.
In our previous studies, lipids and lipophilic compounds of seeds and aerial parts of L. insignis were identified, and the horizontal structure of coenopopulations was determined (Buranova Citation2012, Citation2014, Citation2015).
The aim of our next researches is to study the age composition and assess the current state of L. insignis coenopopulations.
Materials and methods
Coenopopulations of L. insignis located in the southern part of Uzbekistan were selected as research materials (Table 1).
Table 1. Geographic coordinates of coenopopulations of L. insignis.
The age composition of coenopopulations was determined by the results of counting all individuals located inside census sites with a size of 1×1 m. Census sites were set at equal distance from each other and were located along the gradients of coenopopulations. Gradient types were selected based on the geometry of each coenopopulation.
The individuals were counted in the month of April.
The age index of each coenopopulation is calculated based on the results of the delta-omega analysis proposed by Zhivotovsky (Citation2001). To calculate the delta, the following formula was applied, taking into account the contribution of each ontogenetic group to the total age of coenopopulation
(1)
(1)
where ki is the number of the i-th ontogenetic group; mi is the contribution of the age of one individual of the i-th ontogenetic group; N is the number of individuals of coenopopulation.
The following formula is used to calculate the omega or efficiency index:
(2)
(2) where ni is the absolute number of plants of the i-th age state; ei – the efficiency of plants of the i-th age state;
– total number of plants.
Results and discussion
According to our researches, the ontogenesis of L. insignis consists of latent, pre-generative, generative, and post-generative periods. The latent period occurs inside of fruit in the form of seeds (se). The pre-regenerative period is divided into the states of seedlings (p), juvenile (j) and virgin (v) plants. The generative period consists of a single generative state (g), as well as the post-generative period from the senile state (s).
During our researches, the duration of these conditions was established. In particular, the state of the seedlings lasts 9–14 days, juvenile – 16–27 days, virgin – 1–3 years, generative – more than 6 years, senile – 1–2 weeks.
In the coenopopulation of Jingil-1, the average number of individuals in transects was 13.3 ± 0.27 pcs/m2. Of these, 1.61 ± 0.05 pcs/m2 or 10.58% were in the state of seedlings, 1.63 ± 0.05 pcs/m2 or 10.99% were in a juvenile state, 2.27 ± 0.09 pcs/m2 or 15.45% were in the virgin state, 7.71 ± 0.21 pcs/m2 or 57.79% were in the generative state, 1.35 ± 0.05 pcs/m2 or 15.45% were in the senile condition.
As you can see, the largest number of L. insignis individuals are in a generative state. The reason for this is that usually the generative period lasts much longer than all other periods combined.
A similar state was observed in all studied coenopopulations. So, in the Jingil-2 coenopopulation, the share of generative individuals amounted to 64.10% of the total, in the Qoradahana-1 coenopopulation – 68.29%, in the Qoradahana-2 coenopopulation – 61.21%, in the Khujamahmud coenopopulation – 58.55%, and only in the cenopopulation of Beshquton, their share was below half of the total – 43.23% (Figures and ).
Figure 1. Proportion of individuals of L. insignis.
Figure 2. Quantity of individuals of L. insignis.
The total number of individuals ranged from 4.68 pcs/m2 (cenopopulation Khujamahmud) to 22.67 pcs/m2 (cenopopulation Qoradahana-1). Of these, seedlings – 1.16–1.61 pcs/m2, juvenile – 1.24–1.79 pcs/m2, virgin – 1.98–3.91 pcs/m2, generative – 2.74–15.48 pcs/m2, senile – 1.00–1.65 pcs/m2.
The basic spectrum of L. insignis is full-membered, monomodal, right-handed, with a predominance of generative plants, which is characteristic of herbaceous perennials propagating by seeds.
The calculation of the age index of coenopopulations showed that the range of the age coefficient (Δ) of all studied coenopopulations of L. insignis was in the range of 0.4–0.6. On the Zhivotovsky scale, this type of coenopopulation is mature.
The results of calculating the efficiency index (ω) of cenopopulations were in the range of 0.56–0.77 (Table 2).
Table 2. Status of coenopopulations of L. insignis.
Delta-omega analysis showed that Jingil-1 and Beshquton are transitional coenopopulations, Jingil-2, Qoradahana-1 and Qoradahana-2 are mature coenopopulations, and Khujamahmud is senescent coenopopulation.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Data availability statement
Data and materials supporting the results or analyses presented in this study freely available. The name of dataset is ‘Buranova M.O. DAS.xlsx’ which is assessable via https://doi.org/10.17632/ghtp3cmfb8.1
References
- Buranova MO. 2012. Lipids and lipophilic constituents of the aerial part of Lipskya insignis. Chem Nat Compd. 48:301–302. doi:10.1007/s10600-012-0227-z. Springer US.
- Buranova MO. 2014. Lipids from Lipskya insignis seeds. Chem Nat Compd. 50: 122–123. doi:10.1007/s10600-014-0883-2. Springer US.
- Buranova MO. 2015. Horizontal structure of some coenopopulations of Lipskya insignis (Koso-Pol.) Nevsky. Nat Techn Sci. 6(84):128–130. Sputnik +.
- Zhivotovsky LA. 2001. Ontogenetic states, effective density and classification of plant populations. Ecology. 1:3–7.