Tag: travel

THE FORESTS OF NGORONGORO

THE FORESTS OF NGORONGORO

1965: Northern Highlands Forest Reserve, Tanzania

Suddenly, ahead, a soft clunk sounded. Cowbell! The chief forest guard, an older man whose stiff curly hair was sprinkled with white, whispered that we should be especially quiet now. He and I were leading a group of forest guards and game scouts on a patrol for livestock trespassing in the forest reserve. Easing our way slowly around stumps, we carefully pushed branches aside to look ahead, studying each clearing before entering it, tense with anticipation.

“Wewe! Simama!” You! Stop!

“Kamata yeye!” Catch him!

Guards and scouts alike charged into the bushes . . .

Buffaloes by My Bedroom: Tales of Tanganyika.

Now that I’ve grabbed your attention, and you’re wondering what happens next, I’m taking the opportunity to introduce some important background information before resuming the story. In my previous post, I promoted the scenery and wildlife of Tanzania’s Ngorongoro Conservation Area (NCA) to the extent that some readers probably wondered why, if it was so great, it wasn’t a national park. The answer is that it once was. From 1951-1959 it comprised the western part of the Serengeti National Park.

However, difficulties encountered from having people, in this case Maasai pastoralists and non-Maasai cultivators, living in an area strictly devoted to the conservation of wildlife forced the then territorial government to remove the eastern Serengeti Plains and Crater Highlands from the park and place them within a separate entity, the Ngorongoro Conservation Area. This allowed the Maasai to continue their pastoral existence while the government controlled the use of certain key areas, including Ngorongoro and Empakaai craters, the eastern Serengeti Plains, and the archeological site at Oldupai Gorge. Thus, the Ngorongoro Conservation Area became a multiple-use management area, the only one in Tanzania to protect wildlife while allowing human habitation.

A relief map of the Ngorongoro Conservation Area (NCA). Yellow (grassland), gray (bushland and woodland), green (forest), and brown (agriculture). Courtesy of David Bygott and Jeannette Hanby.

The NCA’s montane forests provide an example of multiple use. Ranging in elevation from 5,000-10,000 ft (1,600-3,000 m), most forest cover occurs within the Northern Highlands Forest Reserve, a 50 mile (80 km) band of green on the southern and eastern slopes of the Crater Highlands. Here, monsoonal air masses off the Indian Ocean 200 miles (320 km) away are forced to rise, cool, and condense into mist, clouds, and rainfall. This, together with cool high-elevation temperatures, is conducive to a moist environment. Thus, unlike elsewhere in the Ngorongoro Conservation Area, where green foliage is a seasonal phenomenon, montane forest remains green throughout the year.

Lichens and other epiphytes trailing from branches are associated with abundant mist.

The first thing that struck me upon entering an undisturbed (by cutting, fire, etc.) stand of montane forest was the dim light filtering through the dense canopy 50 to 60 feet overhead. Only here and there did a beam of sunlight slant down to brighten a patch of he forest floor. The next was how a dense understory of shrubs and small trees often hampered my movements, while at other times it was so scattered (or absent) that I could walk freely across the forest floor, the latter made soft and springy by several inches of decomposing organic matter. This made it easier to appreciate the trees, which I differentiated by their many types of bark, which ranged from silver to black, and from smooth to rough, including fissured, corrugated, scaly, flaking, and peeling.

Montane forest within the Northern Highlands Forest Reserve.

Ngorongoro’s forests comprised many tree and shrub species. Some were worthy of note, if only for their descriptive names, including pillar wood (Cassipourea malosana), cheese wood (Pittosporum viridiflorum), brittle wood (Nuxia congesta), and black ironwood (Olea capensis). The latter, also called Elgon olive (for Mt. Elgon on the Kenya-Uganda border), stands out because it is so dense and heavy that it will not float. (Check out the world’s ten heaviest woods at https://www.wood-database.com/top-ten-heaviest-woods/).

Cape chestnut.

Cape chestnut (Calodendron capense) has beautiful flowers. East African pencil cedar (Juniperus procera) is the largest species of Juniper in the world. Mountain bamboo (Arundinaria alpina) is a very large woody grass. The fresh leaves and shoots of Khat or Miraa (Catha edulis) were chewed as a stimulant throughout much of eastern Africa, especially the Horn of Africa. Podo (Podocarpus milanjianus), African mahogany (Entandrophragma angolense), and East African pencil cedar woods were highly prized for construction and other uses. However, these species were not abundant enough in Ngorongoro’s forests to attract commercial operations.

East African pencil cedar forms pure stands in high-elevation ravines within the NCA. The wood of this species was once extensively used to make pencils.
Photo by Sema Tu. Creative Attribution-Share Alike 4.0 International License.
Dense stands of mountain bamboo on Oldeani Mountain (Oldeani is the Maasai word for bamboo). Mountain bamboo has the strange habit of gregariously dying out over large areas every 15 to 40 years or so.

In the case of the Northern Highlands Forest Reserve, a lack of commercially exploitable tree species didn’t matter because its principal purpose, ever since its establishment in 1927, was the protection of forest catchments for water production. Thus, although the forest fulfilled local domestic wood product needs, such as building poles, and firewood, it was far more important for the water (twenty-four small streams and seven springs) it provided beyond its boundaries to coffee and wheat estates, tourist facilities, Mbulu farmers, and Maasai pastoralists. Water infiltrating into the forest’s soils also sustained important groundwater forest habitat over ten miles (sixteen km) away in Lake Manyara National Park (see earlier post, On the Road to Ngorongoro: Part III)

Farms abutting the Northern Highlands Forest Reserve. Most are new since 1965. Photo by David Bygott.

However, the main reason for including the Northern Highlands Forest Reserve in the Serengeti National Park (1n 1951) and then the Ngorongoro Conservation Area (1959), was its value as wildlife habitat, especially for buffaloes, elephants, and rhinos. At the time it was thought that the large animals living in the forest seldom left it, although tourists would often see them along the road. However, subsequent studies revealed that rhinos often traveled back and forth between the forest and the floor of Ngorongoro Crater. Furthermore, before their access routes were blocked by new farms, elephants once moved between the Northern Highlands Forest Reserve and the Rift Valley floor near Lake Manyara .

Picture encountering this while pushing your way through dense undergrowth.
Photo by David Bygott.

Finally, the montane forests of Ngorongoro supported yet another use, a great deal of it illegal. Much of the forest within the Northern Highlands Forest Reserve was discontinuous, separated by secondary scrub and grassy glades. Possible causes included cultivation carried out many years ago, fire, and grazing/browsing by livestock. Maasai herders were sometimes allowed, under permit, to pasture their livestock in forest glades during droughts. Fires, set in the glades to remove dry grass often escaped into the forest, damaging trees. Browsing by livestock destroyed tree seedlings. Trampling hooves compacted soils, reducing their ability to absorb rainfall. These impacts had the potential to seriously reduce the forest’s water catchment value.

It was for this reason that Henry Fosbrooke, the conservator of the Ngorongoro Conservation Area, wanted me, the NCA’s assistant conservator (forests), to stop forest trespass by Maasai livestock. “The forest guards aren’t doing their job properly. You must shape them up.” This explains why, in the first paragraph of this post, I and a group of forest guards and game scouts are portrayed sneaking through the trees trying apprehend trespassing herders and their animals. We now return to that story.

Cattle illegally grazing a glade within the Northern Highlands Forest Reserve. The tall grass, manyatta grass (Eleusine jaegeri), is unpalatable to livestock. The other grasses have been grazed and trampled so heavily that in places only bare soil remains, Fires set in the glade have, in the past, burned away parts of the adjacent forest, giving it an irregular, often open appearance.

The person caught by the scouts and guards was a Maasai herd boy. Soon afterward, they caught another herder, and then another. We nabbed six herders and roughly a thousand cattle that day. Together with those apprehended a few days earlier in another part of the forest, this made ten people and two-thousand cattle. No wonder the forest reserve was degraded. Three days later, the herders and I appeared in a magistrate’s court in the town of Karatu where the African magistrate levied such a small fine that a relative of the herders paid it on the spot.

“They treat these fines as grazing fees” whispered a senior staff member of the NCA, Solomon ole Saibull, into my ear. “They would willingly pay even greater amounts.” Keeping his voice low, he told me that in his experience, African magistrates seldom imposed heavy fines for forest trespass because they didn’t think it was a very important offense. Most Africans, educated or not, considered forest reserves to be relicts of colonialism, set aside by the ‘wazungu’ for their own purposes, not the African’s. “He [the magistrate] probably thinks the reserve should be converted to farms,”Solomon hissed.

Buffaloes by My Bedroom: Tales of Tanganyika.

Here was another factor contributing to degradation within the forest reserve. Now I understood why the forest guards weren’t interested in braving elephants and buffaloes to catch trespassing livestock. Why bother if it did no good? Consequently, despite our efforts, I and the forest guards were to have little impact on the numbers of trespassing livestock during my time at Ngorongoro.

Maasai herders caught trespassing with their livestock in the Northern Highlands Forest Reserve. They were so engrossed in chewing honeycombs that they didn’t hear us approach.

We now jump ahead thirty years. The Ngorongoro Conservation Area Authority (NCAA) general management plan, published in 1996, emphasized, among other things, the continuing need to better control both fire and forest grazing. Apparently, the NCA foresters who came after me also had trouble controlling forest trespass.

Furthermore, the management plan also stated that Ngorongoro’s forests were under considerable pressure from illegal harvesting of trees for local domestic use. This to the extent that Mafu (Fagaropsis angolensis) and Khat or Miraa (Catha edulis) were listed as ‘threatened’ tree species in the Ngorongoro Conservation Area due to extensive logging of the former for building materials, and heavy harvesting of the latter for its drug properties.

This undoubtedly reflects rapid population growth, both within and outside the Ngorongoro Conservation Area (Tanzania’s population approximately tripled from 1960 to 1996), which has created a higher demand for forest products. (For information on population growth in Tanzania, go to https://worldpopulationreview.com/countries/tanzania-population.)

I wonder what the situation is now, twenty-six years later.

ON THE ROAD TO NGORONGORO: PART III (ELEPHANTS AND TREE-CLIMBING LIONS)

ON THE ROAD TO NGORONGORO: PART III (ELEPHANTS AND TREE-CLIMBING LIONS)

Henry and I were enjoying the view from the veranda of the Lake Manyara Hotel. Perched atop the escarpment above Lake Manyara National Park, the hotel commanded sweeping views to the east, south, and north. The Park began almost at our feet, a jumble of trees, shrubs and rocks tumbling down a steep 1800 ft (545 m) escarpment to a narrow, irregular plain of forest, woodland, and grassland bordering the shallow muddy waters of Lake Manyara. Beyond stretched the dry, withered vastness of the Maasai Steppe, its occasional hills and dry stream beds obscured by a haze of smoke from dry-season grass fires.

Figure 1. Lake Manyara National Park begins at the top of the escarpment, extends across Lake Manyara and halfway to its distant southern tip. The building on the right is the Lake Manyara Hotel.

It was 1964. I was a newly arrived U.S. Peace Corps volunteer and Henry was Henry Fosbrooke, old Tanganyika hand and conservator, Ngorongoro Conservation Area. He was driving me to Ngorongoro where I was to take up my duties as assistant conservator (forests). While Henry finished drinking his tea, I gazed over the park. Twenty-five miles long, it was only a few miles wide, and much of this was steep, rugged escarpment. This made me wonder what was important about the park besides a striking view. “Tree-climbing lions,” Henry stated, setting down his tea cup with a forceful clink. “Unique to this park; the only place in Africa where lions climb trees.” (Note: since then, populations of tree-climbing lions have been found elsewhere, including Ngorongoro, Tarangire, and the Serengeti in Tanzania as well as Queen Elizabeth National Park in Uganda.) Beckoning for a waiter to bring the bill, he added, “There also are rather a lot of elephants.” That did it: I would visit the park the first chance I got.

Figure 2. A tree-climbing lioness in Lake Manyara National Park.
(Photo by David Bygott, co-author with Jeanette Hanby of the book, Spirited Oasis:Tales from a Tanzanian village.)

Lake Manyara National Park is a good example of how the escarpments, lakes, and volcanic highlands of East Africa’s eastern rift valley have influenced the region’s biological diversity, not to mention its scenery.

At 123 sq. miles (318 sq.km), 70% of them water, the park was small. In comparison, the Serengeti National Park, 55 miles to the west, could contain 46 Lake Manyara National Parks.

Figure 3. Lake Manyara National Park includes the northern half of Lake Manyara. The Tarangire Game Reserve (now a national park) lies to the southeast, across the Great North Road.

Nonetheless, it was ecologically diverse. The combination of rocky escarpment composed of ancient basement system and younger volcanic rocks, large shallow lake, and narrow plain watered by perennial streams and springs has created habitats ranging from closed canopy forest through deciduous woodland and thicket, to open grassland and swamp. Examples of three of the most important habitats follow:

Figure 4. Elephant dreaming in a forest glade.
(Photo by David Bygott.)

Forest: Fed by springs flowing from volcanic rock at the base of the escarpment, groundwater forest consists of plants that could not grow under the existing rainfall. It also contains grassy glades and swamps. The spring water originates outside the park, from rainfall falling on the forested outer slopes of the Crater Highlands thirty miles away.

Figure 5. Acacia woodland.
(Photo by David Bygott.)

Acacia woodlands: haunt of tree-climbing lions. No one knows for sure why they spend so much time resting in trees. The more plausible theories include keeping away from herds of buffaloes and elephants and/or from biting flies. (Another, possibly tongue-in-cheek, suggestion is that the trees are simply easy to climb.)

This raises a question: buffaloes are the principal prey of the park’s lions, so why should lions avoid them? Buffaloes are big, mean, and hard to kill. They can put up a real fight when attacked. Consequently, Manyara lions lead harder lives than their Serengeti cousins, who frequently feast off hyena kills. This probably accounts for their desire to keep clear of buffalo herds until hunger drives them to hunt again.

Figure 6. Open grassland.
(License:: Attribution-Share Alike 4.0 International [CCBY-SA 4.0]) OLYMPUS DIGITAL CAMERA

Grasslands support a large proportion of the park’s animal biomass. One of the more important types is strongly influenced by Lake Manyara in that it occurs on alkaline soils of periodically flooded mud flats. Alkali grassland fluctuates widely in area depending on the level of the lake, but is, nonetheless, heavily grazed by buffaloes, gnus, and zebras.

Large and shallow (max. depth 12 ft or 3.6 m), Manyara, like other rift valley lakes, has no outlet, losing its water only through evaporation. Therefore, its area and depth can vary significantly over time. For instance, in 1961, the lake was so dry it could be crossed in a Land Rover, whereas in 1962 rising waters killed many trees along the shore and forced zebras and wildebeests, the latter then the principal grazers on alkali grasslands, into the woodlands where they were easy prey for lions. This destroyed the wildebeest population, which took several years to return. The lake gives, but can also take away.

The varied habitats of Lake Manyara National Park provide optimal conditions for many species of wildlife: klipspringer and Kirk’s dik dik on the rocky escarpment, impala and giraffe in the woodlands, various waterbirds (at times an estimated two million) on the lake . . . However, none benefit more from this habitat diversity than elephants, which can use them all (except perhaps the lake). They can pull up tussocks of grass, forage branches up to 20 ft (6 m) high, wade into swamps to eat aquatic plants, and even carefully negotiate parts of the escarpment. Therefore, it wasn’t surprising that there were a lot of them in the park.

Figure 7. Elephant browsing an umbrella acacia (Acacia tortillis).
(Photo by David Bygott.)

However, there was another, more ominous, explanation for their high numbers: hunting and loss of habitat to agriculture might be driving elephants into the park. If so, they could become so numerous as to outgrow their food supply. In such cases it’s the trees and shrubs that are most affected. If short on forage, elephants will strip bark and eat the cambium, push trees over to get at out-of-reach foliage , dig up tree roots, and gouge holes into baobab trees to access water stored in their trunks. Thus, the most visible impact of elephant overpopulation is the destruction of forests and woodlands.

Furthermore, this already was happening elsewhere. For instance, in Uganda’s Murchison Falls National Park some 1000 sq miles (2290 sq km) of woodlands would be destroyed by 1969. Worse yet, there were signs of damage to trees in Lake Manyara National Park where many Acacia tortilis (umbrella acacia) trees had been knocked down and/or stripped of their bark.

Figure 8. Elephants in the Serengeti browsing the upper branches of a fever tree (Acacia xanthophloea) they have pushed over.

This led Tanganyika National Parks to ask a young British zoologist, Iain Douglas-Hamilton, to study the situation. Iain spent the next few years identifying individual elephants and studying their behavior. He recorded what they ate and their impact on the vegetation. He learned how to age them and monitor their growth. He recorded births and when one died tried to find out why. He counted them and followed their movements. Large as they were, elephants still were hard to spot in areas of dense vegetation, so Iain immobilized a few of the big animals, fitted them with radio collars and tracked them from an airplane, which he also used to census their numbers.

Figure 9. Iain Douglas-Hamilton’s camp on the Ndala River

And, along the way, he had some exciting experiences. A partial list includes being hospitalized by an encounter with a rhino while on foot in dense bush, being swept downstream from a causeway while trying to cross a river in flood, and, on three occasions having his vehicle bashed up by elephants. As described in Among the Elephants, these incidents were scary enough to make a prospective wildlife biologist choose another career. That said, except for the rhino encounter, it was Iain’s Land Rover that sustained the most damage. Holed, ripped, bent, and lifted by angry elephants, its fenders were crumpled, roof squashed, and windows broken; the big animals sometimes pushed it around like a baby carriage. It’s a wonder the vehicle lasted through Iain’s study. Nonetheless, it did and here are some of Iain’s findings:

(a) Manyara had the densest elephant population of any park in Africa, well over 10 / sq. mile (3.0 / sq km). Elephants dominated the park’s large-mammal biomass (with buffaloes coming in a close second);

(b) Fortunately, the park’s elephants were not completely confined to the park but had access to the Marang Forest Reserve above the escarpment to the southwest. This reduced the chances, at least for the time being, of their numbers overwhelming the food supply;

(c) Nonetheless, Manyara’s elephant population still might someday outgrow their food supply, destroy their habitat, and starve.

Therefore, Iain proposed the acquisition of land owned by European farmers (many of whom were already leaving the country) at the south of the park. This would provide more room for the park’s elephants but also allow them access, across lightly settled land south of the lake, to the Tarangire Game Reserve (now national park) ten miles to the east (Fig. 3).

Over thirty years later, in 2009, Tanzania National Parks finalized this acquisition, providing hope for the future of Manyara’s elephants.

Iain’s Land Rover did not get bashed in vain.