climate change on UAE - Stockholm Environment Institute-US Center

5. Important flora in
Abu Dhabi
Abu Dhabi has a remarkable number and
variety of habitats, plant and animal species.
Many habitats and species have come under
severe threat, primarily due to the rapid rate
at which the emirate has developed, and
continues to develop. According to Kürschner
and Boer (1999), the flora of the UAE contains
more than 630 species, and comprises elements
from both Asia and Africa. In addition to about
20 bryophyte species, they highlighted that the
greatest number of species recorded in the UAE
are therophytes. The therophytes appear after
rains and disappear in dry periods. In general
terms, the natural UAE flora could be classified
according to the following ecological categories:
seagrass, mangrove, salt marsh, reed swamp,
sand dune, gravel plain, desert wadis, and
rocky-mountainous vegetation.
formation below the high-tide mark. They exist in
coastal ecosystems in a transitional environment
between land and marine, characteristic of
tropical regions subject to the action of tides. It
is constituted of woody tree species and many
micro and macroalgae adapted to fluctuations
in water salinity, shifting sediments with low
levels of oxygen and naturally occur in the
intertidal zones (Chapman, 1976).
Impacts, Vulnerability & Adaptation for
Dryland Ecosystems in Abu Dhabi
Apart from these, there are several oases with
date palm vegetation, and urban green areas
within the UAE. Because of the prevailing
desert like conditions, the flora of the UAE is
widely scattered across different habitat types
e.g. coastal, mountain, wadis etc. Moreover,
the soils of the UAE are characterized by their
aridity, sandy nature, low water retention
capacity, nutrients and organic matter (Boer
and Sargeant, 1998). The arid environments
have their impact on the plant structure and life,
as the flora of the UAE mainly comprises thorny
shrubs, therophytes (ephemerals, annuals,
biennuals), xerophytes, psammophytes and
halophytes.
Also, there are some hygrophytes growing in
the shaded humid wadis of the mountains, and
some hydrophytes in the inundated ecosystems
of the UAE. A recent study in Abu Dhabi (UAE,
2008) indicated that Abu Dhabi is a home to
approximately 400 species of vascular plants, 50
species of mammals, 416 bird species, 55 species
of reptiles, and between 4,000 and 5,000 species
of invertebrates. More details on some floral
and faunal types is given in the subsequent
sections.
5.1. Mangroves
Walsh (1974) defines mangroves as a woodland
Mangroves require a fine-grained alluvial
substrate and shores that are not exposed to
strong wave activity that could otherwise wash
the seedlings away by the action of currents.
It is also widely known that, coastal processes
such as tidal mixing and coastal currents may
also influence mangrove distribution through
affecting dispersal ability (McLeod et al., 2006).
Climatic factors such as temperature and
moisture affect mangrove distribution (Duke,
1992; Saenger, 1993). Temperatures above 35°C
have led to thermal stress affecting recovery
rates following the disturbance. (Ning et al.,
2003).
Mangroves are known to be important
biomass producers and exporters to coastal
environments (Dahdouh-Guebas et al. 2000).
They provide protection and refuge for juvenile
fish and are important in increasing fishery
production on the coastline (Laegdsgaard and
Johnson, 2001). Only one species of mangrove,
Avicennia marina occurs naturally in the UAE,
possibly due to the harsh summer <strong>climate</strong>,
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