Phenology, morphology and variability in pollen viability of four woody species (Cordia boissieri, Parkinsonia texana, P. aculeataandLeucophyllum frutescens) exposed to environmental temperature, north-eastern Mexico

The research, in 2004, was focused on the whole population of Anemone sylvestris (Snowdrop Windflower) present in the area of a kettle hole (0.8 km2) in north-eastern Poland (52°50’00’’N; 23°11’20’’E). The location of 56 clumps of generative specimens was surveyed. They numbered from several to approx. 1500 specimens. The number of generative specimens in this population exceeded 10 000. On account of this, it is a unique stand of A. sylvestris in Poland. The relationship between the occurrence of the Snowdrop Windflower and the presence of kame hills and ridges has been proven. Low slopes of kame with an inclination of 10-20o, and a north-eastern or eastern exposition has been found as the local ecological optimum for this species. Research carried out in 1970-2001 on 5 permanent plots (25 m2 each) has shown that: 1) Anemone sylvestris is an essential element of xerothermic grasslands of the order Festucetalia valesiacae; 2) the species suddenly withdraws from the parts of land on which woody species have already reached the shrub layer; 3) the greatest danger for the population of A. sylvestris in this area is the process of secondary succession initiated by the discontinuation of grazing on the kame hills.

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Floristic diversity and demographic structure of the Sidi R'Ghies forest, north-eastern of Algeria

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d210304 ◽

2020 ◽

Vol 21 (3) ◽

Author(s):

MALIKA RACHED-KANOUNI ◽

KARIMA KARA ◽

Hichem Khammar ◽

LABED ABABSA

Keyword(s):

Floristic Composition ◽

Woody Species ◽

Diversity Indices ◽

Mature Stage ◽

Arid Zones ◽

Floristic Diversity ◽

Demographic Structure ◽

Plant Resources ◽

North East ◽

North Eastern

Abstract. Rached-Kanouni M, Kara K, Khammar H, Ababsa L. 2020. Floristic diversity and demographic structure of the Sidi R'Ghies forest, north-eastern of Algeria. Biodiversitas 21: 875-881. In Algeria, the degradation of the ecosystems induces a loss of biodiversity and an increase in the adverse effects of climate change and anthropogenic actions, especially at the level of the ecosystems of semi-arid zones. This study aims to determine the floristic composition and demographic structures of different stands within the Sidi R'Ghies forest, north-east of Algeria. Data were collected using floristic surveys, diameter measurements at 1.30 m and total height for trees in four plots with size for each plot of 1000 m2. The diversity indices have been calculated on the basis of specific frequencies. The analysis revealed a low floristic richness with 6 woody species belonging to 5 families with the most dominant are the Cupressaceae and Fagaceae (29%). The low density of woody trees (97.78 individuals/ha) was found in Plot 1 and the high density of 205.56 individuals/ha was found in Plot 4. The diametric structure adjusts to the Weibull distribution and shows a predominance of young individuals. The distribution of trees in height classes shows a single distribution with an asymmetric curve. This positive distribution reveals a predominance of individuals with a height between 2 and 8 m (sapling to mature stage). This work, which provides an overview of the state of the floristic diversity of the Sidi R’Ghies forest, allows taking appropriate measures to safeguard our plant resources.

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