November 2016

Variance in yield and production of nectar, and their effect on the visit of pollinators to the Rosemary, a Mediterranean shrub

Tamar Keasar – The Department for Biology and Environment, Haifa University-Oranim
Adi Sadeh, – Southern R&D,  Besor Farm
Avi Shmida – the Department of Evolution, Systematics and Behavior, and the Federmann Center for the Study of Rationality at the Hebrew University in Jerusalem, Givat Ram.

Keywords: honey bee, pollination, alien pollination, nectar yield, nectar production, Rosemarinus officinalis, variance in nectar yield, Lamiaceae

Different flowers that grow on the same plant, frequently contain very different quantities of nectar. These differences may result from the foraging activity of the pollinating insects in the plant's flowers. Alternatively, they might reflect the effect of natural selection that grants an advantage to high variance in the nectar production among flowers. This variance is expected to shorten the sequence of visits by "risk hating" pollinators to a single plant, to cause them to go over to a neighboring plant and thus reduce the risk of self-pollination.  In this study we examined the contribution of the pollinators and of the plants themselves to variance in the nectar yield on the Rosemary (Rosemarinus officinalis) shrub of the Lamiaceae family, that is pollinated primarily by bees. We measured the rate of nectar production, nectar yield (the quantity of nectar in flowers) and the visits of the insects to three plants from a single population, over the course of 17 days during a single flowering season. We found high variance in the rates of nectar production (the variance coefficient=1.48), which was greater after rainy days.  The variance of the nectar yield was even higher (variance coefficient=2.16). It fell with the temperature and rose with the time that went by since the last rain. The rate of the bees' visits fell as the differences in the nectar yield grew, rose upon the increase in the number of open flowers on the shrub, was not affected by the variance in the rate of nectar production in the flowers. Repeated sampling of marked flowers that were emptied of nectar, did not show a distinct correlation between nectar yields in the flowers, and the rates of nectar production later on.  From these results we conclude that high variance in the nectar yield among flowers of the same plant reduces the number of the bees' visits of the shrub before they move on to another shrub. However, the plants do not have full control over this variance, which is regulated particularly by the foraging of the pollinators.  The partial control of pollinators regarding the variance in quantities of nectar is expected to reduce the evolutionary advantage of the plant from the creation of nectar reward among different flowers on the same plant.

Full Hebrew version

The Box-elder Maple  – a new alien tree along the River Jordan: could it turn into an invasive tree?

Avi Shmida – the Department of Evolution, Systematics and Behavior, and the Federmann Center for the Study of Rationality at the Hebrew University in Jerusalem, Givat Ram.
Jean-Marc Dufour-Dror – ecologist, researcher, and expert of invasive plants
Photographs: Ohad Cohen – and Yaki Ashkenazi, the Land of Israel Studies Department at the Kinneret College on the Sea of Galilee

Keywords: Aceraceae, river banks, dioecious, samara, wind pollination, waste habitats, Sapindaceae, colonizing plant, cultivated plants, invasive plants,  introduced xenophytes

The Box-elder Maple (Acer negundo), a tree of North American origin, has spread over the last 130 years in many temperate regions outside the American continent. The tree is characterized by rapid growth, extremely strong renewal capability, and high spreading capacity in space despite its being a dioecious tree that is wind pollinated. It grows and spreads along rivers and damp canals on road-sides, in temperate climates without a dry season.  During a trip held by the Land of Israel Studies Department in the mountainous Jordan, under Jacob's Ford on November 10 2016, we found two mature, seed-bearing Box-elder Maple trees, which had settled on the Jodan River bank. This is the first discovery of this invasive species in Israel, in a natural, undisturbed habitat.

Full Hebrew version

The uses of the Syrian Mesquite for food and remedy

Avivit Bercovic – instructress for foraging and cooking in nature, the Israel Foraging Center of Excellence
Participated: Tzvia Shapira-

Keywords: liver diseases, recipe, diabetes, polyphenols, fruit, flavonoids, edible plants, medicinal plants, legumes, popular medicine, Mimosaceae, folklore, traditional medicine

The leaves and fruit of the Syrian Mequite (Prosopis farcta) are used for food and traditional-popular medicine among Arabs and Bedouins in Israel, as well as additional countries in the Middle East. A recipe for a dish made of the Syrian Mesquite's fruit is presented in the article. Traditional medicine attributes to the essences of the Mesquite a variety of medicinal effects. Several studies, in which laboratory animals were treated with the essences of the Mesquite fruit, and studies under in-vitro conditions showed an improvement is diabetes, an effect on the liver in the direction of reducing the level of harmful blood fats, and anti-inflammatory  activity against bacteria and fungi.

Full Hebrew version

Summary of the Kalanit study tour in the Jerusalem Corridor – November 24, 2016

Avi Shmida – the Department of Evolution, Systematics and Behavior, and the Federmann Center for the Study of Rationality at the Hebrew University in Jerusalem, Givat Ram.
Atai Yoffe – Israeli garden at Nativ HaLamed Heh
Gadi Pollak – Kalanit editorial

Keywords: Biarum bovei, Pistacia atlantica, the four species, Hirbet Adulam,  Ne'ot Kdumi, Nahal Natuf,  Autumn flowering,  the seven species, Ziziphus spina-christi

The study tour took place against the background of the dry weather conditions of the current autumn season, and  the paucity of rain. Consequently, the flowering of the geophytes  that bloom in November and the beginning of December following the downfall of the first rain, has been delayed.  At the Land of Israel Garden at Netiv HaLamed-he we learnt about the special booming biology of the Blue Star Water-lily (Nymphaea nouchali) and the species of the fern species that grow wild in Israel. We learnt about the biology and ecology of the Mount Atlas Mastic Tree (Pistacia atlantica) at Hirbet Adulam.  At the botanical garden of Ne'ot Kdumim we focused on the Syrian Christ's Thorn (Ziziphus spina-christi) and the Sycamore, and we ended the study tour touring the park at Ne'ot Kdumim and Nahal Natuf – where special emphasis was placed on the natural vegetation, which was enriched with additional elements based on the bible and cliff flora.

Full Hebrew version

The Desert Bindweed – an extremely rare endangered plant, which is to be found in the Jordan Valley Rift

Bar Shemesh – Unit for Surveys of Nature and Open Spaces, at the Deshe Institute
Amir Perelerg – Unit for Surveys of Nature and Open Spaces, at the Deshe Institute
Amos Sabah – Judea and Samaria district, the Nature and Parks Authority
Mimi Ron – Unit for Surveys of Nature and Open Spaces, at the Deshse Institute

Keywords: Wetland, the Jordan River floodplain Convolvulus prostratus, Convolvulaceae, salt marsh, Lisan formation, nature conservation and endangered species, distribution of plants in Israel

In the course of an ecological survey in the Jordan River floodplain on April 21, 2016, a population of the Desert Bindweed  (Convolvulus pilosellifolius) was observed. This species was defined in the Red Book of plants in danger of extinction in Israel, as a species that is extinct (Shmida and Pollak, 2007).  The population that was found numbers dozens of items that grow in a natural and damp habitat in the Jordan River floodplain, in the company of salt marsh plants. This is unlike the habitat in which the species was collected in the past – fields and irrigated date groves. A systematic inquiry led to the conclusion that the identification of the Desert Bindweed as Convolvulus pilosellifolius is correct, and is not to be confused with the Bushy Bindweed (Convolvulus prostratus), as was suggested in the Red Book of Israeli plants. The systematic proximity of the Desert Bindweed and the Bushy Bindweed is discussed in the article, as well as their phytogeographic affinity to the Irano-Turanian region on the one hand, and the Sudanian region on the other.

Full Hebrew version

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