BBC地球系列：非洲（2013）

The Sahara is too large to go around.
家燕别无选择 只好迎面而上
The swallows have no choice but to meet it head-on.
他们将展开自然界最伟大的迁徙之旅
It will take one of nature's greatest feats of navigation
飞越这片毫无生机的荒漠
to cross this lifeless wasteland.
狂沙漫漫 一眼望不到边
A wilderness that stretches not just to the horizon,
广袤到无法想象
but almost beyond imagination.
它是地图上一片巨大的空白
It's an immense blank space on the map.
尽管撒哈拉以沙漠着称
In spite of the Sahara's reputation,
但沙地的面♥积♥还不到五分之一
less than one-fifth of it is sand.
其余的则是石头和风蚀岩
The rest is stone and wind-scoured rock.
烈日不仅炙烤着大地
The sun not only bakes the land,
也肆意地扭曲着地貌
it warps its appearance.
过热的空气从沙漠的地面上升起
The superheated air, rising upward from the desert surface,
扭曲了远处的景象
distorts the distant scene.
天边的映像在沙漠中闪烁
A reflection of the sky shimmers on the sands,
呈现出海市蜃楼
a mirage.
太阳就是一位迷幻大♥师♥
The sun is an illusionist.
对饥渴的旅者来说
To thirsty travellers,
海市蜃楼呈现出湖的幻像
a mirage can resemble a lake
每将接近它时 它却后退 令人苦闷
which agonisingly recedes as it's approached.
而摇摇摆摆前来救援的骆驼
And swaying camels coming to the rescue
却变成了干枯多刺的刺槐
transform into dry, spiny acacia trees.
要穿越这个迷惑闪烁的沙漠
To cross this confused, shimmering landscape,
家燕需要在海市蜃楼间寻找真正的水源
many swallows will need to find real water amongst the mirages.
即使在撒哈拉沙漠 有时候也会下雨
Even in the Sahara, rain does sometimes fall
只要植物有顽强的适应力
and that is sufficient for plants to survive
就能够存活下来
providing they have the right adaptations.
沙漠中出现了一个枝叶干枯缩卷的小球
Rising from the sand, a dried-out ball of twigs.
强风中 它随风而行
In strong winds, it can travel.
它可能已经死去了100年
This plant may have been dead for 100 years.
然而从名字看来 它的生命并没有结束
Yet its name suggests that all is not lost,
因为它是一株复活植物
for this is a resurrection plant.
在这里 一年只可能会下一两次雨
Around here, rain might only fall once or twice a year.
但对于已经寻觅水源数十载的植物来说
But if you're searching for decades,
那点雨水就已经足够了
that might be enough.
死去的枝干吸收水分
Dead limbs absorb water
大约几分钟内它就展开了
and unfurl in a matter of minutes.
但这株复活植物还需要一个奇迹
But the resurrection plant needs one more miracle.
在它再次干枯萎缩之前
Rain must fall on its branches
雨必须落到它的枝干上
before they dry out and close up again.
几小时之内 嫩芽破土而出
Within hours, shoots emerge.
只要几周 它们便会开花结果
In just a few weeks, they flower and develop seeds of their own.
然后 在它们长得更大之前
Then, before they can grow any larger,
烈日又杀死它们了
the sun kills them.
但是它们的种子存活下来了
But their seeds live on,
等待着上天再次降雨
ready for when the rains return,
即使又是一个百年
even if that is a century from now.
北非的环境并非一向如此恶劣
North Africa wasn't always so brutal.
撒哈拉沙漠中零星散落着生命的遗迹
Scattered across the Sahara are glimpses of life
正是大灾难之前生命存在的证据
before the apocalypse swept over the land.
在北部 有一座石化森林
In the north, a petrified forest,
树木变成了石头
trees turned to stone.
那是来自遥远湿润历史的遗迹
Remains from a far distant, wetter past.
撒哈拉沙漠中♥央♥的白色沉积物
White sediments in the heart of the Sahara
正是湖泊干涸后的痕迹
are the dried-out remains
那曾是世界上最大的湖泊
of what was once the world's largest lake.
在东部 古城废墟
In the east, ruined cities
提醒着人们那曾经繁荣的时代
hark back to a time of plenty.
在利比亚的中心地区
And here, deep inside Libya,
在麦萨克塞塔菲特
is Messak Settafet.
岩石上刻满了数百幅动物图像
Carved here are hundreds of images of animals,
全都源于生活
all drawn from life.
古时的幽魂
Ghosts from a greener time.
古老北非的残迹竟有一处幸免于难
Remarkably, a remnant of this old North Africa survives.
突尼斯布哈德玛国家公园依靠山地降雨而生
Bou-Hedma, in Tunisia, is sustained by mountain rains.
那是曾覆盖整个北非的大草原最后的遗迹
It's a relic of the savannah that once carpeted North Africa.
当地球运行轨道移♥动♥
The vast grassland vanished
使雨水南移时 辽阔的草原也随之消失
when a shift in the Earth's orbit drove the rains south
而仅仅过了几个世纪
and, in perhaps only a matter of centuries,
撒哈拉沙漠就吞没了整个北非
the Sahara Desert overwhelmed North Africa.
有证据表明 这一切发生在6千年前
The evidence suggests this took place around 6,000 years ago.
在进化过程中 那算不上什么
In evolutionary terms, that's no time at all
生灵们几乎没有可能适应这个新环境
and life has had little chance to adapt to this new world.
只有少数的强手
Only a few tough specialists
才能找到在沙漠中的生存之道
can cope with life amongst the dunes.
骆驼有时被称为"沙漠之舟"
Camels are sometimes called "Ships of the desert"
但就像家燕一样
but, like the swallows,
他们也只是过客
they're really only visitors here.
那些"舟"可以穿越撒哈拉
These "Ships" can certainly cross the Sahara,
但他们也无法在这种严酷的环境里生活
but even they can't make their home in the harshest places.
如果任由他们在沙漠漫行
Left to wander the desert by themselves,
骆驼是无法存活的
camels would not survive.
他们得依靠人类的导航才能找到绿洲和水井
They depend on their human navigators to find oases and wells.
撒哈拉的民间传说中 有许多都是关于
Saharan folklore is full of tales
商队因错过几百米外的水井而失踪的故事
of caravans that missed a well by a few hundred metres and disappeared.
眼前是埃及境内的白沙漠
This is the White Desert, in Egypt.
此处遍布着巨大的柱形白垩
The landscape is littered with giant chalk pillars,
是由长♥期♥的风沙侵蚀而成
carved by innumerable sandstorms.
这些耀眼的白岩石极其炙热
This glaring white oven is lethally hot.
在这里根本无法找到食物
Food here is almost non-existent.
但路过此处的骆驼会留下珍贵的小礼物
But there's a rare gift from a passing camel.
粪便的气味能够引来数英里外的蜣螂
The smell has lured dung beetles from miles around.
对他们来说 这就是天上掉下的馅饼
For them, this is manna from heaven.
一个粪球足以供这只雌蜣螂
One dung ball could provide enough food
享用一辈子了
to last this female beetle the rest of her life.
但她面临一个问题
But she has a problem.
为了保持粪便的新鲜
To keep it fresh,
她必须把粪球埋入潮湿的土壤中
she must bury it in moist ground.
那可不容易找到
And that's not easy to find.
此时 温度已上升了10度
The temperature has already risen ten degrees.
这只蜥蜴逃离了炽热的沙地
This lizard avoids the roasting sand.
虽然离地面只有30厘米
Only 30 centimetres above the surface,
但已经凉快多了
it's significantly cooler.
蜣螂采用的"倒推式"技术
The 'reverse-pushing' technique
绝对是持续前进的最快方法
is certainly the fastest way to keep the ball rolling.
但也有一个缺点
But it does have one drawback.
无法看到前方的情况
You can't see where you're going.
太不幸了
Disaster!
她被困在了两个沙丘之间
Stuck between two dunes.
那粪球是她自身的两倍重
The dung ball is twice her weight,
但这依然无法打消她继续前进的念头
but the urge to keep pushing is inextinguishable.
气温已经升到了41摄氏度
Now, it's 41 degrees Celsius.
她很快就会被烤死
Soon, she'll be baked alive.
最终 求生本能超越了她对粪球的热爱
Her survival instinct, in the end, over-rides her love for dung.
撒哈拉大部分区域都不适合居住
Much of the Sahara is uninhabitable,
但也有极少数的地方可以生存
but there are rare places where there is some possibility of survival.
比如那些在偶然情况下囤积了水源的地方
Places where, by strange chance, there is water.
瓦安纳姆斯是一座死火山
Waw An Namus is an extinct volcano.
从太空中看
From space,
它就像利比亚撒哈拉上的一块黑色疤痕
it's a remote, black scar on the Libyan Sahara.
但也有其他颜色
Yet there are other colours here,
一些极少在沙漠中看到的颜色
colours rarely seen on the desert floor.
蓝和绿
Blue and green.
几千年前的撒哈拉还是一片绿色
Rain fell thousands of years ago, when the Sahara was green
雨水下落渗入地下
and percolated deep into the ground.
现如今 水从这片广阔而古老的水库
And here water, from this vast ancient reservoir
升至地面
rises to the surface.
这些水池再一次展现了撒哈拉往昔的风貌
These pools offer another glimpse of the Sahara's past.
在北非 只要是有水源的地方
Wherever there's water in North Africa,
就是那些幸存的古老生物的依附之地
living relics from this wetter time have a chance to cling on.
这片绿洲依赖于炙热的火山温泉