December 2015

This is autumn – reflections on the seasons of the year in Israel, following the autumn blooming

Uzi Paz

Keywords: spring,  first rainfall,  geophytes, winter, harbingers of rain, harbingers of winter, harbingers of autumn,  winter bloomers, summer

How many seasons are there in the year? In the literature there are those who dispute the division of the year into four seasons, and reject the autumn and the spring as "legitimate" seasons. In their opinion there are only two seasons in Israel: summer and winter, or the rainy season and the hot season.  The nature of the seasons of the year in Israel is different to that in Europe, but this does not justify the rejection of the existence of autumn and spring in Israel as well.
The shortening of daylight in autumn is a basic signal, which causes more than 30 species of geophytes to flower then.  However, they also require a short-term signal.  For some of them, which are called "autumn harbingers", this is a dose of cold. Others require the first rains – irrespective of its date. These are the "first rain plants".

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Reaction to the article "Criteria for defining invasive plants in Israel and risk assessment" (November 2015)

Ofer Steinitz, Israel Nature and Parks Authority,
Margareta Walczak, Israel Nature and Parks Authority
Noam Lieder, Israel Nature and Parks Authority
Anna Trachtenbrot, Ministry for the Environment
Yehoshua Shkedi, Israel Nature and parks authority

Keywords: invasive species, biological invasion, Acacia saligna, Acacia salicina

Cohen's and Riov's article (2015) proposes a new definition of invasive species.  In reaction to the article we point out the problems involved in this definition, and reject it. The Book of Invasive Plants in Israel (Dufour-Dror, 2010)  includes the common definition for invasive plant species, and constitutes the professional basis for work that is already being carried out on the terrain today to confront the biological plant invasions.

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Species of Biarum in Israel: summary of the knowledge and innovations

Dar Ben-Nathan, hiker and plant lover, Arad
Oz Golan, The Center for Materials Engineering and Processes, Afeka College for Engineering in Tel-Aviv
Shimon Dadon, hiker and member of the Kalanit circle,
Aharoni and Yael Mor, members of the Kalanit circle, Kibbutz Kinneret
Uri Stein hiker and member of the Kalanit circle,
Avi Shmida, the Department of Evolution, Ecology and Behavior, and the Federmann Center for the Study of Rationality at the Hebrew University in Jerusalem, Givat Ram.

Keywords: Biarum pyrami, Biarum negevensis sp. nova, Biarum bovei, geophytes,  beetle polination, Araceae, vicarious species, autumn bloomers, black flowers, Israeli flora, allopatric distribution

Following the article About the Biarum: the genus and species that grow in Israel and its environs in Kalanit (October 2014), many populations of the Biarum pyrami (Sec. Ischarum) were examined throughout Israel, and especially the structure of the pollination chamber and lower rachis.  The results presented in this article focus on the  Bove's Biarum (Biarum bovei), the Galilee Biarum (Biarum pyrami), and the Yellow Biarum (Biarum auraniticum), and describe a new species – the Negev Biarum (Biarum negevensis sp. nova). Additional information is presented on the various species of Biarum, and the relations among them.  We prefer to call most of the species common in Israel Biarum pyrami, and leave the question whether Biarum bovei grows in Israel to when peace will prevail, when we shall be able to compare the populations of the northern Golan Heights and the Galilee with those in Lebanon from whence it was described for science.  The Negev Biarum is described here as an endemic species to the northern Negev.

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Avinoam Danin 1939-2015

Hagar Leschner

On Saturday, December 13, 2015, Professor Avinoam Danin passed away, following a fatal illness.
Avinoam was a man of Israel's vegetation and flora in both body and soul.  He was extremely knowledgeable, eager to teach whatever he knew, and bequeath the wonders of the botanical sciences, and familiarity of plants to his students and  everyman. In the ceremony in which he was granted a award by the Israel Society of Ecology and Environmental Sciences  for his life achievement, Avinoam Danin said of himself that love of flowers had been an inseparable part of him since he started to walk.
The flora guide that Avinoam Danin wrote together with Prof. Naomi Feinbrun-Dothan is the "yellow Bible" of all wild plant lovers in Israel.  The website and database  which he created, are a highly important tool of getting to know plants that is a precious heritage for the knowledge of Israel's flora.

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A new site for the Dwarf Maresia in Tel-Aviv – Jaffa

Ori Fragman-Sapir, the University Botanical Garden, Jerusalem

Keywords: sand dunes, bilogical diversity, Coastal Plain, Malcolmia, Maresia, endangered plant

The Dwarf  Maresia (Maresia nana), an endangered species in danger of extinction that grows in the Sand Dunes of the Southern Coastal Plain and in the Sharon, has been found in a new site in eastern Jaffa. This is the only site known today in Tel-Aviv – Jaffa. In the past there were several sites within the limits of Tel-Aviv where the plant has become extinct.  However, in the Holon sand dunes there are a few more ties where the plant still survives.

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Defining invading plants, and a discussion of the status of Eucalyptus camaldulensis as a possible invader in Israel

Jean-Marc Dufour-Dror, ecologist specializing in introduced alien plants and invasive plants and their eradication

Keywords: Eucalyptus camaldulensis, seed dispersal, invasive trees, introduced plants,  Acacia saligna

Following the article by Dr. Oded Cohen and professor Yossi Riov on "criteria for defining invasive plants in Israel and assessing risks" a reaction has been presented  that explains the theoretical basis for defining an invasive plant species, accompanied by examples of plants from the world and from Israel. The definition includes quantitative indices, and is accepted by most experts in the world in the field of the ecology of invasive plants.  An explanation is provided for why it is preferable to a theoretical definition, which details the quantitative ecological components of distribution distance, rate of invasion and consolidation of introduced plants: an incidental  stage, a naturalization stage, and an invasive stage. Examples are offered of such plants abroad and in Israel.  The status of  the River Red Gum (Eucalyptus camaldulensis) as an invasive species into the natural ecological systems in Israel is discussed in great detail, as an example for the need to apply clear and quantitative criteria.

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