TITLE:
Succession of the Plant Communities of the Ustyurt Eastern Cliff (Republic of Uzbekistan) in Connection with Climate Change
AUTHORS:
Adilov Bekhzod, Rakhimova Tashkhonim, Shomurodov Khabibullo, Rakhimova Nodira, Vokhidov Yusuf
KEYWORDS:
Ustyurt Plateau, Eastern Cliff, Climate Change, Species Diversity, Total Projective Cover, Invasive Species
JOURNAL NAME:
Journal of Environmental Protection,
Vol.9 No.13,
December
19,
2018
ABSTRACT: A decrease in the amount
of precipitation is observed on average 18 - 20 mm compared with the
periods before the Aral crisis and the average annual temperature rise over the
long-term period is 2.0°C in the Central part of Ustyurt. An increase in the Si index meaning an increase in the
degree of drought every ten-flight
is clearly expressed in the months March-July. Data Analysis 1981-2017 shows
that within 36 years the species diversity in the monitoring sites of Kabanbay
decreased by 2 - 3 times. In 1981 the number of
species fluctuated between the values of 9 - 50, and in 2017 this figure
is 4 - 17. The results of the
analysis show that the forecast indicators of the old-current state (1981) of
the vegetation coverage and number of species were stable or had tendencies
with a low regressive character (r2 = 0.01). However, the current-state (2017) of the vegetation coverage and the
species composition of the monitoring plots showed a low progressive trend (r2 = 0.03), i.e. in the future, the formation of
plant communities with low vegetation coverage and species composition has a
dominant status. The results show that in 1981, 65% - 80% of the species
composition of plant communities consisted of halophyte and xerophyte groups.
In 2017, this figure reaches 80%
- 100%, i.e. this claims to increase xerophytization and halophytization of territories. An
interesting fact is established with mesophyte group. In general,
theoretically, the decrease in the number of mesophyte group of plants for
1981-2017 would have a direct correlation with the vegetation coverage and
their active share in it. However, for 36 years, their active share in the
vegetation coverage remained unchanged—amounting to 0% - 20%. Of course, in these
years, the decrease in the number of mesophyte plants led to an increase in the
number of plant communities, in which the proportion of vegetation coverage of mesophyte
group is insignificant—0% - 5%. Despite the drought,
the active part of the vegetation cover of mesophytic invasive species, such as Poa bulbosa, is consistently
maintained.