Last ancient Huarango and Algarrobo forests. Fog oasis, desert woodlands.
Peru’s southern coast is […]
[a]n extension of the famous Atacama desert of northern Chile, it is one of
the driest places on Earth, with an average annual rainfall of 0.3 mm,
or barely more than one tenth of an inch.
[…]
This story of deforestation is in fact almost complete, with nearly 99% of the original vegetation having been removed.
[…]
The other unique feature of the southern coast is an inland archipelago
of sorts, made up of coastal fog oases, or lomas, in Spanish. Fed by the
moisture provided by coastal fogs, they rise from the surrounding
desert and harbor herbaceous vegetation and in some cases various kinds
of trees, all of which show high rates of endemism.
“The last remaining stretch of Prosopis limensis riparian forest near Copara, Ica region, southern Peru.”
“A female Andean condor (Vultur gryphus), in the Lomas de San Fernando reserve, the only place in Peru where this raptor roosts near sea level.”
“The amazing vegetation supported almost entirely by coastal fogs in the Lomas de Atiquipa, home to an endemic very endangered Myrtaceae: Myrcianthes ferreyrae.”
“There once were countless Prosopis trees such as this one, which has probably lived for a thousand years on this sand dune, near Copara.”
500 years ago, the river valleys were occupied by dense woodlands or
veritable forests of Prosopis limensis (local name – Huarango), which is
often misidentified as Prosopis pallida, teeming with wildlife in the
canopy and understories. Today, most of the Prosopis
are gone, the excellent charcoal produced from their wood having been
used up to fuel the stream engines of the now defunct coastal railway
[…].
Here more than in nearly any other desert, life is almost entirely confined to areas with some amount of moisture. As a result, the few river valleys that come down from the Andes form spectacular green ribbons among the dunes. They carry some water down from the rainstorms high in the mountains but the critical driver here is El Nino. It brings down tremendous amounts of water and sediment once every 6 to 15 years, thereby rejuvenating the whole system […].
“The remarkable woodlands dominated by Prosopis pallida (Algarrobo), in the Pomac Forest Sanctuary, Lambayeque Region, northern Peru.”
“A seed-ball with 4 native species, including Algarrobo, being prepared at a community nursery, near Salas, Lambayeque region.”
[Restorationists] are also engaged in restoration efforts the tropical northern coast of
Peru, where the circumstances are rather different. The north coast
receives significantly more rainfall than the south, i.e., about 100 mm
per year (!), that is 4 inches. This permits the vegetation to climb out
of the river valleys, and in fact, the local Algarrobo (Prosopis pallida and in the extreme North only P. juliflora along with hybrids between the two), and Capparis
species, among others, still form true woodlands. […]
However, a still poorly understood plague, apparently resulting from the
combination of a small fly and a fungus, are decimating the woodlands;
in some areas over 80% of the Algarrobo have apparently died. Just like
in the South, El NiNo is paramount in keeping the system healthy and, in
particular, no Prosopis seedlings have been seen germinating in the
last 50 years, except during El Nino years.
The Algarrobo, like the Huarango, is a remarkable tree, fantastically
well adapted to its environment, capable of living 1000 years of more,
and clearly the keystone species of the riparian and related ecosystems
where it occurs. It forms remarkable canopies, and in areas where it is absent, we did
not see the other tree species present produce anything like it, rather
forming a much more open low savanna.
“A thousand-year old Prosopis pallida in the Pomac Forest Sanctuary, possibly the oldest of its kind still alive in northern Peru …”
—
Text,photos, captions:
James Aronson and Thibaud Aronson.
“The Huarango and Algarrobo forests of coastal Peru: rays of hope.” Missouri Botanical Garden - Ecological Restoration. 3 January 2016. Italicized heading: me.
