Bark hive beekeeping and forest maintenance - Part 1

Bees for Development Journal 140 September 2021

Janet Lowore, Programme Manager, Bees for Development

Bark is a marvellous and versatile material and is widely used to make bee hives, particularly in miombo forest areas such as north-western Zambia. The use of bark is much criticised by foresters, and development professionals, as being harmful to forests. In this series of articles, we examine these criticisms in detail and propose an alternative paradigm.

Bark bee hive making involves peeling the pliable bark off a tree and allowing it to re-form into its natural cylinder shape, then pegging the overlapping edges together. Both ends are closed using a circle of bark or wood and the hive is allowed to dry before hanging in a tree to attract a swarm of bees. Only certain tree species are suitable for making bark hives. In the North Western Province (NWP) of Zambia the preferred species include Brachystegia boehmii, Brachystegia spiciformis and Julbernardia paniculata. Trees of the right size and shape must be selected but some trees which appear suitable do not have the necessary crossgrained fibres to give the resulting hive its strength.

Beekeepers test a small part of the bark before harvesting and if the grain is vertical, and not crossgrained, they leave it. These factors: size, species, form and grain mean that only a small percentage of trees in a forest meet the exacting requirements.

Sustainability

Hives are placed many metres apart, a pattern which reflects the dispersed way trees are used for hive making – tree use is not intensively concentrated

Images @ Bees for Development

Dimas Sakalechi making a bark hive in Ikelenge. In NWP Zambia there is no evidence that after generations of bark hive making, beekeepers are obliged to use smaller trees. Hive making activities have not led to a shortage of suitable trees. Some beekeepers report shifting working locations in response to localised shortages and returning once smaller trees reach maturity

The main criticism of bark hives is that the removal of bark causes the tree to die. Yet cutting trees to make planks also causes trees to die and top-bar hives and frame-hives, often promoted as ‘better’ alternatives to bark hives, are made of planks. So, killing trees is not the problem here – we also use trees for many other purposes! Is the rate of use equal or less than the rate of replenishment? The answer is a function of how many hives are made each year, from a hectare of a given forest and the rate of re-growth. It is rare for any human activity to have no impact on the environment. With bark hive beekeeping, we accept that making hives harms individual trees, but what about the forest as a whole? Is the forest harmed, or indeed helped, by the sum of all the activities of bark hive beekeepers? The focus of these articles is Zambia, where miombo forest beekeeping has been most studied - miombo forest beekeeping extends also throughout Angola, DR Congo, Mozambique and Tanzania.

Some people argue against bark hive beekeeping because of the colony management limitations posed by fixed-comb hives. We refer you to other articles which report on the bee health advantages of fixedcomb hives and their success in yielding very large volumes of honey, visit www.resources.beesfordevelopment.org

Offtake versus replenishment

A way to consider whether the rate of use is matched by the rate of replenishment is to analyse data about the number of beekeepers, the area of forest from which they harvest bark, the number of hives they make each year (a function of longevity of each hive and number of hives owned) and the rate of tree growth.

Bark is removed from the stems of living trees to make hives. The trees do not recover but the rate of use in NWP Zambia is sustainable

Bark hives underpin a beekeeping system where beekeepers efficiently manage the resources they have – bark, bees, bee forage and their own labour and skills to harvest high quality honey and beeswax

This question, in relation to NWP Zambia was considered by Clauss (1992). His results indicated that 3.1 trees were used per km 2 , while the estimated number of suitable specimens to be 224 trees per km 2 . At this rate of use, given the availability of suitable trees, a regrowth period of 72 years would allow for sustainability, and it is likely that hive-sized trees are less than 72 years old. A subsequent estimation using data from IFAD in 1999 concluded ‘the overall number of trees remain in a range that implies relatively low levels of damage, which are likely to be within the limits of replacement’. These estimates were updated (Mickels-Kokwe, 2006). Her assumptions included an increase in number of beekeepers, an increase in number of hives made per beekeeper and a decrease in forest area. As a consequence of her extrapolations she concluded that by 2006 the rate of tree use per km 2 had risen from 3.1 to 4.9 which pushed the necessary regrowth period from 72 years down to 45 years, whereas other data (Stromgaard, 1985) suggested that trees of bark-making dimensions are 50 years old.

Mickels-Kokwe warns against jumping to conclusions that bark hive beekeeping causes deforestation and explains that the selective nature of the harvest minimises the overall impact of the activity. It is important to remember that while Clauss estimated there to be 224 suitable trees per km 2 , there are thousands of other trees in the same area which are not impacted by hive-making because they are not suitable. Mickels-Kokwe (2006) does suggest four possible concerns:

• Trees suitable for hive-making may become scarce, obliging beekeepers to use smaller trees

• The constant off-take of suitable trees may erode the genetic base

• Removal of trees for hive-making may reduce nectar availability

• Pressure on specific trees may change the woodland composition

We examine this question again, but not by trying to recalculate the current rate of use, through measuring and counting trees, hives and beekeepers, because there is significant room for error. In my research (Lowore, 2016-2018) I learned that the largest honey buying company in NWP Zambia, Forest Fruits Ltd (FFL) buys from 3,000 registered beekeepers, a far smaller number than the 17,640 beekeepers estimated by Mickels-Kokwe in 2006 – although of course not every beekeeper sells to FFL. The area of forest used for beekeeping in Zambia is estimated but does not consider that Zambian beekeepers extend their activities into DR Congo and Angola (confirmed by beekeepers I worked with in 2018). The number of hives made each year by one beekeeper varies depending on the prevailing honey prices and the reliability of the honey market, but there is a selfimposed limit set simply by the effort of the beekeeper. Most beekeepers do all their own work, with possibly one helper. They do not have time to make and maintain hives in ever greater numbers. In 1992, Clauss recorded the average hive ownership of beekeepers in Mwinilunga to be 110, my research suggested that the average ownership was 89-115 hives each, so no significant increase in the intervening years. Have the concerns posed by Mickels-Kokwe in 2006 materialised in NWP Zambia?

Are beekeepers using smaller trees to make bark hives?

In my research (2018) I measured trees used to make hives. The average diameter over bark of trees used to make hives was 35cm with average hive diameter 30cm. Clauss (1992) reports that in Mwinilunga, hives are typically 20-25cm in diameter, whilst Simplified beekeeping with bark hives (Forestry Department, n.d.) states that hives should be 120cm long and 30cm in diameter. These results suggest that hives made in 2018 are no smaller than in previous years and suggest that Mickel-Kokwe’s first warning that beekeepers will be constrained by lack of hive material and be forced to user smaller trees is not the case – or at least not in this location. During interviews, beekeepers explained that if they face difficulty in finding trees suitable for hives, they do not use smaller trees because that would be a waste of effort. Smaller hives may not attract or accommodate a bee colony which results in lower honey yields or total failure. Their tactic is to look for trees elsewhere. In Ikelenge and Mwinilunga beekeepers are not constrained provided they are willing to walk long distances: maybe a problem for the beekeeper, but not for the forest – this is a well – established conservation tactic: desist from harvesting from places of scarcity and shift to places of abundance.

A typical hive site in Mwinilunga, Zambia. Most trees are unsuitable for hive-making – crooked or the bark is not useable – but are maintained for their nectar, pollen, and other benefits

Changes to genetic base and woodland composition?

Does the constant removal of suitable trees erode the genetic base and hinder natural regeneration? Information about the age of seed-bearing of miombo species is hard to find. One report notes that ‘Julbernardia globiflora reproduces while still a small sapling and Brachystegia only reproduces when the plant emerges in the canopy’ (Campbell, 1996). Trees of diameter 34cm, 135m above ground, are between 40-60 years old (Stromgaard, 1985) and have had several years of seed bearing by the time of harvest. On B. spiciformis it is noted that ‘The ground under the trees is frequently saturated with seedlings’ (Bingham, 2010). The tree species used for hive-making are not uncommon and not endangered: B. spiciformis is reported to be the most widespread of the Brachystegia sp (Bingham 2010) and a recent Zambia land cover report records that B. spiciformis and J. paniculata are the two most abundant species in Zambia (ILUA II, 2016). These are two of the most preferred tree species for hive-making. Bark hive making has been occurring at scale for decades in Zambia and these two tree species are still abundant, suggesting that fear that they are failing to regenerate because seed-bearing trees have been removed is unfounded.

It is widely understood by forest ecologists that miombo woodland withstands moderate harvesting pressure without regeneration potential being harmed. Work done by Chidumayo (2013) reports, ‘Where these [biomass] losses were relatively small in relation to the standing biomass, no obvious impact was observed in standing biomass stocks. A decrease in tree population appeared to reduce competition and enhanced the growth of the surviving trees and in many cases the standing biomass either remained the same or actually increased’.

The impact of light canopy removal on seedling recruitment is also noted by other forest scientists. ‘The high level of recruitment of saplings from the seedling pool that have been stunted suggests that further development of seedlings with well-established roots is suppressed by the woodland canopy. Lees (1962) also observed that old but stunted seedlings of many miombo woodland trees are heliophytic and require high light intensities to develop and grow’. The implication of this capacity to sustain regrowth is that miombo woodland can sustain heavy cutting pressures (Campbell 1996).

Reduced nectar availability?

The largest honey buying company in NWP Zambia is FFL. In the years since they began buying honey their year-on-year purchases exhibit growth and not decline. With exceptions due to poor weather, the supply of honey is increasing. A major driver of honey supply in miombo countries is the reliability and accessibility of the market. Where the market is good, beekeepers supply honey. During 2009-2013, FFL bought 500 tonnes of honey a year, by 2019 this had risen to 1,000 tonnes – all from beekeepers using bark hives. This strongly suggests bark hive beekeeping is not reducing nectar availability.

Beekeepers are not wasteful: where possible they make several hives from one tree

Conclusion

There is no evidence that using bark to make hives has a negative impact on the health of the forest ecosystem.

In the next article we recognise that the first people to notice shortage of hive-making trees will be the beekeepers themselves and we will report their experiences.

In the final article we will return to the question of trade-offs and consider the wider impact of bark hive beekeeping on the environment, rather than looking narrowly at hive making alone, and explore whether the forest is helped or harmed, by the sum of all the activities of bark hive beekeepers.

References

BINGHAM,M.G. (2010). Notes on Zambian trees: Brachystegia spiciformis - Muputu. Black Lechwe, 17(1), 16–18.

CAMPBELL,B. (1996). The Miombo in Transition: Woodlands and Welfare in Africa. The Miombo in Transition: Woodlands and Welfare in Africa. Bogor: Center for International Forestry Research. Retrieved from http://books.google.com/books?hl=nl&lr=&id=rpildJJVdU4C& pgis=1

CHIDUMAYO,E.N. (2013). Forest degradation and recovery in a miombo woodland landscape in Zambia: 22 years of observations on permanent sample plots. Forest Ecology and Management, 291, 154–161. https://doi.org/10.1016/j.foreco.2012.11.031

CLAUSS,B. (1992). Bees and beekeeping in the North Western Province of Zambia. Ndola: Mission Press, Zambia.

IFAD (1999). Republic of Zambia. Forest Resource Management Project. Post- appraisal report. Volume II Annexes. IFAD Africa Division II, Programme Management Department.

ILUA II. (2016). Integrated Land Use Assessment Phase II – Report for Zambia. Lusaka: Forestry Department, Ministry of Lands and Natural Resources. Retrieved from https://prais.unccd.int/sites/default/ files/2018-08/ILUA II_Final Report_Zambia_19062016.pdf

LOWORE,J. (2021). Forest beekeeping in Zambia: analysing the nexus of sustainable forest management and commercial honey trade. Unpublished PhD thesis, University of Huddersfield, UK.

FORESTRY DEPARTMENT. (n.d.). Simplified beekeeping with bark hives. Lusaka, Zambia.

MICKELS-KOKWE,G. (2006). Small-scale woodland-based enterprises with outstanding economic potential: the case of honey in Zambia. Bogor: Center for International Forestry Research.

STROMGAARD,P. (1985). Biomass, growth and burning of woodland in a shifting cultivation area of South Central Africa. Forest Ecology and Management, 12, 163–178.

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Dimas Sakalechi making a bark hive in Ikelenge. In NWP Zambia there is no evidence that after generations of bark hive making, beekeepers are obliged to use smaller trees. Hive making activities have not led to a shortage of suitable trees. Some beekeepers report shifting working locations in response to localised shortages and returning once smaller trees reach maturity