Nature Forest Reserves in Tanzania and their importance for conservation

Since 1997 Tanzania has undertaken a process to identify and declare a network of Nature Forest Reserves (NFRs) with high biodiversity values, mainly from within its existing portfolio of national Forest Reserves, but with some new extensions. In recent years this expansion has accelerated, with ten NFRs declared since 2015. The current network of 19 existing NFRs covered 918,212 hectares by the end of 2020 (with an additional three reserves covering 34,862 hectares in the process of being declared). The coverage by NFRs of Tanzanian habitat types has increased to include the main forest types, wet, seasonal, and dry, and includes wetlands and grasslands. This has led to more than a doubling of the coverage of species ranges of vertebrates by the NFR network. Declared and proposed reserves now contain at least 178 of Tanzania’s 242 endemic vertebrate species, of which over 50% are threatened with extinction, and 553 Tanzanian endemic plant taxa (species, subspecies, and varieties), of which 61.3% are threatened. NFRs also support 41 single site endemic vertebrate species and 76 single site endemic plant taxa. Time series data show that NFR management effectiveness is increasing, especially where donor funds are available. Tourism, diversified revenue generation and investment schemes are required to create a network of economically self-sustaining NFRs able to conserve critical biodiversity values. Improved management and investment have reduced some threats in recent years, but ongoing challenges include illegal logging, charcoal production, firewood, pole cutting, hunting, fire, wildlife trade, and the unpredictable impacts of climate change.


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The creation of protected forest areas in Tanzania has a long history stretching back to the 82 resources have been deployed to the most important sites to achieve conservation goals, and 83 (iii) assessing the coverage of endemic and rare species by the NFR network and other 84 protected areas across Tanzania. We discuss the findings in light of our own insights into 85 management challenges in the NFR and ways that these might be addressed in the future.  correlation between the number of taxa and the date of declaration was tested using the non-

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parametric Spearman's rank correlation coefficient as our data were not normally distributed.

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The Management Effectiveness Tracking Tool (METT; [17]) was used to assess and compare 146 the effectiveness of each NFR, alongside tourist numbers, income generated, management 147 capacity, and forest disturbance. As previously, our data were not normally distributed; 148 therefore, the possible correlation was tested using the Spearman correlation test in R.

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To We found that older NFR sites support a larger number of recorded threatened taxa when 188 compared to recently declared sites ( Figure 2A and Table 3). Amani, Kilombero, and Uluguru Uzungwa Scarp, Rondo, and Magamba. Many of these species are also endemic to Tanzania 191 (see Figure 2B, Amani to Mangula). Predictably, as new reserves were added to the network

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This overall significant increase is also found in each taxon group separately (Spearman 197 correlation test, rho = 0.95, p < 0.001 for each taxon group). We found no significant correlation

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between the year of establishment and the reserve area (p = 0.8755).

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Including all types of protected areas present in Tanzania, the proportion of gap and poorly 294 bird species considering only the NFRs (Table 2). Almost 7% of endemic amphibian species 295 remain unprotected, compared with approximately 11 % in NFRs (Table 2).   (Figures 2: B, C, D). The network of reserves now covers most of the endemic and 322 threatened vertebrate species in Tanzania, however, not their full ranges. The most important 323 sites in terms of biodiversity value also show slightly higher METT scores, suggesting that 324 resources have been allocated to more important sites (Figure 3: B), even though the increase 325 is small.

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Do gaps remain in the NFR network?
328 As more reserves have been added to the NFR network over time, the proportion of gap 329 species has decreased for all species groups ( Figure 5). This is especially true for endemic 330 mammal and bird species, which respectively had 5% and 0 % of gap species remaining after 331 all NFRs were added to the network. However, the proportion of poorly covered species 332 increased for some groups such as birds, which had more than 30% of species poorly covered 333 including in all the NFRs compared to 26% including only Amani NFR ( Figure 5). Due to the 334 relatively small size of the NFRs and the large range of some Tanzanian endemic species,

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NFRs could not adequately cover the ranges of all the endemic species in the country. To 336 achieve a larger coverage of the ranges of these species we needed to include other types of 337 terrestrial protected areas in our analysis (Figure 7) [27].

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The major NFR gap area identified was in the coastal forests (Figures 6 and 7). Even after NFRs and increasing revenue collection, but the potential to pay the full management costs 372 remains low and care must be taken not to develop facilities that remain under used.

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The fact that forest disturbance (using the proxy of cut trees and poles) generally declined   protected areas is associated with lowered tropical mammal diversity. Animal