In attempts to clarify conservation efforts for African lions, two workshops were held by the IUCN, one in 2005, the second in 2006 [1,12]. An outcome of these workshops was to identify Lion Conservation Units (LCUs), defined as “an area of known, occasional and/or possible lion range that can be considered an ecological unit of importance”. Listed LCU's were also assigned population trends although it is not possible to derive the basis of such assignations. As such, the population trends must be considered speculative in a scientific sense.
Although not specifically stated within the publications from these workshops that each LCU is ecologically independent, it is assumed as such as defined by Chardonnet (2002). He describes units similar to the identified LCUs stating that sub-populations were “distinct populations separated by: natural barriers such as large rivers or mountain ranges, and/or; extensive areas of human settlements, and/or; very large distances”.
The long-term importance for lion conservation of many LCUs is questionable, as viability is highly dependent on free population interchange. The Gorongosa / Marromeu LCU in Mozambique, for example, covers an area of 42,000km2 with an estimated “increasing” population of 100 – 250. Gorongosa NP, one of two protected areas within the range, has an estimated population of 34 – 60 lions  with little or no possible natural immigration due to the Park’s isolation by community areas with an estimated 250,000 population .
Similar criticisms apply to the multi-country LCUs (Guinea/Guinea-Bissau/Mali/Senegal in the case of the Niokolo-Guinea LCU and in Botswana, Zimbabwe and South Africa in the case of the Shashe-Limpopo LCU). While the contiguous LCUs (Serengeti/Mara, Okavango/Chobe/Hwange, Ruaha, Selous and Greater Limpopo) can be viewed as containing populations of significant importance to overall conservation plans for the species by far the largest percentage of LCUs were designated based on incomplete, unsubstantiated, and anecdotal information on lion numbers. This applies especially to countries like Sudan, Democratic Republic of Congo, Angola, and Somalia from which no reasonable lion numbers can be expected to be produced in the foreseeable future. As an example of such uncertainty, of 109 locations reported by Bauer and van der Merwe  to contain lion populations, 76% of estimates were based on various categories of “guesses”. In only 14% of locations could numbers be confidently estimated using recent surveys and/or data based on actual counts.
LCUs were assigned trends that acknowledge levels of confidence of future viability of the populations, but overall, the LCU approach is currently flawed and compromised by reliance on population data with little hope of substantiation.
In 39% of LCUs, populations were considered as stable or increasing with 43% decreasing and 17% of unknown trend. The latter populations are typically in areas of civil strife, such as Somalia; lion populations in these areas are likely to be in decline. As an example of further concerns over the accuracy of the LCU approach; of the four LCUs wholly or partly within Kenya, two were identified as having stable populations whilst one was identified as having an increasing population. These trends contradict latest estimates of lion numbers provided by the Kenyan Wildlife Service  further raising concerns over the validity of the trend assignations for other LCUs.
Further, recent surveys  in West and Central Africa produced alarming results; lion presence could be confirmed in only 2 of 12 IUCN identified LCUs studied in the West African region. The authors concluded that “It is unclear whether our results indicate a true deterioration in lion status since 2005-6 or whether the LCUs in question were delimited based on out dated or inaccurate information. Our survey results suggest a combination of both.”