Introduction

For millions of people around the world, forests are the vital basis of life for national economic development as well as a carbon sink that will later contribute to climate protection. In all respects the peoples of the world are dependent on either wood or other forest products. Obtaining individuals who are free from addiction to forest products is equivalent to obtaining electrons for free. The viability of restoration choices can be affected by the differences in ecological and socio-economic conditions, political and authentic settings, and level of management¹. By excluding invasive species (negative factors in land restoration), land exclusion plays an important role in balancing the ecological and human foundations of life. Before establishing the exclusion, the surface/land should be scanned for pre-existing invasive alien species. Enrichment plantings should also be carried out after the introduced species have been checked for invasiveness. The establishment of restricted livestock areas or species protection support agricultural growth because they protect water catchment areas, stabilizes the local climate and the hydrological system. Community cooperation could be an essential ingredient for land restoration ventures to enhance the level of residential fulfilment and to progress its victory rate². Nevertheless, there are socioeconomic and demographic components, which decide the level of interest in such projects. The absence of advantage from the preserved zone, level of education, and sexual orientation are among the basic variables of community interest in land reclamation. Therefore, this review paper is aimed to create awareness through providing information and documenting files on the socio-economic and soil nutrient improvement role of previously established exclosure land uses.

Development

Exclosure on soil erosion reduction and fertility improvement. In Ethiopia, inadequate agricultural practices such as cultivation on steep slopes, clearing of vegetation and overgrazing are the main factors leading to soil erosion and nutrient loss^3-5. For instance, cultivation on the steep slopes in northern Ethiopia resulted in a loss of 35 tons of soil per hectare of land annually⁶. But today such a devastating loss of soil is being reduced by exclosures. For this reason, it was established as a form of land management with a spatial focus to improve environmental conditions and control soil erosion^5,7.

The role of exclosure on soil fertility is measured through considering the availability of essential nutrient (micro and macro nutrient) for plant growth. Nitrogen (N), Phosphorus (P), Potassium (K), Sulfer (S), Calcium (Ca), Magnesum (Mg), Iron (Fe), Zinc (Zn), Manganese (Mn), Cuppor (Cu), Borun (B), Molybdenum (Mo), and Chlorine (Cl) are among the essential nutrient for plant growth⁸. Mekuria et al⁹. and Conant et al.¹⁰ reported that variation in soil type, land-use history, land cover, climate, topography and vegetation cover creates difference in the content of soil organic carbon stock of a converted grazing lands (exclosure land). Due to such variability the contributions of exclosure for soil physical and chemical properties were studied in different way by different authors.

For instance, Abay et al.¹¹ reported that converting open grazing land into an exclosure improved most soil properties except soil pH, avP and EC. They reported that exclosure had a significantly (p <0.05) higher SOC which shows an improvement of 46.5 or 61.3 % compared to grazing land. Besides, they said that, it increases CEC, TN and avK levels significantly (p <0.05) by 16.8, 45.5 and 34 %, respectively.

Mekuria and Aynekulu¹² reported that the availability of N, P and CEC is varying with the age of exclosure and soil depth. They said that prevention of grass harvesting leads to raise the available soil P and N. Damene et al.¹³ also recently reported that management of degraded land by converting open grazing land to exclosure land with chomo grass sowing practice significantly enhances the total available N and SOC than open grazing lands (Table 1).

Table 1
Summery of Soil fertility role of Exclosure land use

CEC= Cat ion exchange capacity, EC=electric conductivity, TN= total Nitrogen, avP=available phosphorus, avK= available Potassium, SOC=soil organic Carbon.

Macro and micro nutrients	Its availability in the exclosure land relative to adjacent open grazing land	Suggested reason	Reference
TN	Insignificant change ( but 0.45 times better than AOG land)	High SOC and legumes plant availability might enhance TN in the exclosure.	7,11
avP	Insignificant change (but 0.15 times higher than AOG land)		11
avK	increase(0.34 times better than AOG land)		11
SOC	Increase(>0.5 times of open grazing land)	High litter fall from tree/shrub	7,11,16
PH	No significant change is observed	Different temperature and rain fall varies SOM decomposition rate	1,11
CEC	Insignificant change(but 0.16 times higher than AOG land)	Different temperature and rain fall varies SOM decomposition rate	11
EC	Decrease (0.14 times lower than AOG land)	Might be due to high vegetation cover that optimize evaporation and infiltration	11

The presence of improved soil structure (high level of leaf litter and vegetation cover) in the exclosure land reduces the soil erosion better than open grazing land^11,13.

Study done in the upper Blue Nile basin of Ethiopia shown that the use of area exclosure with trenches is a best option for soil erosion and runoff reduction¹⁴. While for soil loss reduction issue alone, use of area exclosure is suitable land management practices¹⁴. The improvement in canopy and ground cover in area exclosure with increasing age of exclosure reduces sediment associated nutrient loss through lowering raindrops and soil erosion^4,12,15.

Socio-economic impact of exclosure land. In this review paper, the socio-economic role of exclosure land focus on family size, gender, income, occupations, culture, perception and attitude of the society, educational status of the society. The contribution of forests to total household income in the northern highlands and southern Ethiopia was 27 % and 34 %, respectively^17,18. Although such benefits are obtained, deforestation due to population pressures in Ethiopia is severe and has a long history, particularly in the central and northern highlands¹⁹.

To avoid such problems, the rehabilitation of degraded forests and woodlands by ecological and environmental viable (area exclosure and enclosure) land management practise is currently seen as a critical issues^19,20. In addition to its role in regulating ecosystem services, the exclosure has socio-economic benefits for the livelihood of the community^18,21-25. For example, the preservation of tree species in the vicinity of the church boundary is considered a heritage and offers spiritual benefits to society. Their role in demarcating the affected country and expressing the culture of a society is great as the facility requires less manpower^26,27. The establishment of the exclusion had negative^23,25 and positive^4,28, attitudes towards the local community. Accordingly, the positive attitude of the local community is crucial for the sustainability of the exclosure and future rehabilitation measures.

The economic role of exclosure can be direct or indirect. Its direct role for the local community is expressed through the provision of animal feed, bee fodder, fuel and other non-wood forest products^17,21 (Table 2). A study conducted in Biyo-Kelala Area Enclosures, Ada`a District, Eastern Shewa Zone, Oromoia Region, showed that income from exclosures was approximately 3.07 % of total annual household income²⁹. The indirect benefits of excluser have also been achieved through improving land productivity and regulating environmental services³⁰. Studies done in the semi-arid lowlands of northern Ethiopia showed that converting communal grazing land into exclosure land over 30 years was achieved the US $ 3.071 per hectare³⁰. The conversion of the aboveground carbon stock into the monetary value of a relatively older excuser also creates a lot of economic benefit to a community and natural environment improvement. Conservation includes the preservation, maintenance, sustainable use, restoration and improvement of the natural environment. In this regard, Exclosure helps support the sustainable use of natural resources there by generating environmental, economic and social benefits for the rural communities³¹. This allows the local community to alleviate poverty by extending the vegetation cover on the degraded land.

Table 2
Summery of socio economic role of exclosure

hh=household

Reviewed Socio economic parameters	Reference
Protect cultural heritage.	32
Shelter to several wild animal.	32
Act as esthetical value.	32
Spiritual significance.	32
Provision of fruit and medicine.	33
Provides fodder for livestock.	34
Improve hh (household) income.	17,34
Create Job opportunity to hh (wild fruit collection, fodder sell, bee keeping, mushroom collection, guard, grass cut and carry).	33
Improve the communal resource management skill of community.	35

hh=household

Conclusion

Extensive dependence of rural household on the natural resource leads to resource degradation. Equitable resource distribution among end-users is important to sustainable forest land reclamation. Medicine, fuel wood, fruit, honey, aesthetic value, cultural value and spiritual uses were some of the socioeconomic uses of exclosure land to the rural households. Participation of local community on integrated soil erosion control practice in the exclosure land use enhances soil fertility when it is governed by local bylaws. Generally, the household who got benefit form land reclamation practice more motivated to protect other similar featured lands. In doing so, communities’ attitude towards exclosure land use improves with improved ecological systems. Further studies of the use of exclosure land use on gender, education level and age group should be done and documented for end-users. In addition to this studies on the equal distribution of resource to the community should be done to reduce conflict among exclosure land user households and get benefits sustainably. Studies on enhancing the advantage of local communities, their preferred tree/shrub, grass and spice species that should be planted in the exclosure land uses is also needed.

Cited Literature

1. Munie Shiferaw AM. Effect of plantation forests on soil chemical properties, soil temperature and regeneration of woody plants: a comparative analysis [thesis dissertation]. [Brno]: Mendel University in Brno; 2013 [cited 2020 Oct 18]. Available from: https://www.academia.edu/35550541/effect_of_plantation_forests_on_soil_chemical_properties_soil_temperature_and_regeneration_of_woody_plants_a_comparative_analysis

2. Fakere AA, Ayoola HA. Socioeconomic characteristics and community participation in infrastructure provision in Akure, Nigeria. Cogent Soc Sci 2018;4:1437013. DOI: https://doi.org/10.1080/23311886.2018.1437013

3. Lemenih M, Karltun E, Olsson M. Soil organic matter dynamics after deforestation along a farm field chronosequence in southern highlands of Ethiopia. Agric Eco-syst Environ 2005;109:9-19. DOI: http://doi.org/10.1016/j.agee.2005.02.015

4. Mekuria W, Veldkamp E, Haile M, Gebrehiwot K, Muys B, Nyssen J. Effectiveness of exclosures to control soil erosion and local community perception on soil erosion in Tigray, Ethiopia. Afr J Agric Res 2009;4(4):365-77.

5. Abebe T, Hunde Feyssa D, Kissi E. Area ex-closure as a strategy to restore soil fertility status in degraded land in Southern Ethiopia. J Biol Chem Research 2014;31(1):482-94.

6. Keyzer MA, Sonneveld BGJS. The effect of soil degradation on agricultural productivity in Ethiopia: a non-parametric regional analysis. In: Heerink N, van Keulen H, Kuiper M, editors. Economic policy and sustainable land use. Switzerland: Springer Nature; 2001. p. 269-92. DOI: https://doi.org/10.1007/978-3-642-57558-7_16

7. Yimer F, Alemu G, Abdelkadir A. Soil property variations in relation to exclosure and open grazing land use types in the Central Rift Valley area of Ethiopia. Environ Syst Res 2015;4:17. DOI: https://doi.org/10.1186/s40068-015-0041-2

8. Akenga P, Salim A, Onditi A, Amir Y, Waudo W. Determination of selected micro and macronutrients in sugarcane growing soils at Kakamega North District, Kenya. J Appl Chem 2014;7(7): 34-41. DOI: https://doi.org/10.9790/5736-07713441

9. Mekuria W, Langan S, Noble A, Johnston R. Soil restoration after seven years of exclosure management in northwestern Ethiopia. Land Degrad Dev 2017;28(4):1287-97. DOI: https://doi.org/10.1002/ldr.2527

10. Conant RT, Ogle SM, Paul EA, Paustian K. Measuring and monitoring soil organic car-bon stocks in agricultural lands for climate mitigation. Front Ecol Environ 2011;9(3):169-73 DOI: https://doi.org/10.1890/090153

11. Abay K, Tewolde-Berhan S, Teka K. The effect of exclosures on restoration of soil properties in Ethiopian lowland conditions. SN Appl Sci 2020;2 :1771. DOI: https://doi.org/10.1007/s42452-020-03538-9

12. Mekuria W, Aynekulu E. Exclosure land management for restoration of the soils in degraded communal grazing lands in northern Ethiopia. Land Degrad Dev 2013;24(6):528-38. DOI: https://doi.org/10.1002/ldr.1146

13. Damene S, Bahir A, Villamor GB. The role of Chomo grass (Brachiaria humidicola) and exclosures in restoring soil organic matter, total nitrogen, and associated functions in degraded lands in Ethiopia. Reg Environ Change 2020;20:92. DOI: https://doi.org/10.1007/s10113-020-01680-z

14. Ebabu K, Tsunekawa A, Haregeweyn N, Adgo E, Meshesha DT. Aklog D, et al. Effects of land use and sustainable land management practices on runoff and soil loss in the Upper Blue Nile basin, Ethiopia. Sci Total Environ 2019;648:1462-75. DOI: https://doi.org/10.1016/j.scitotenv.2018.08.273

15. Tefera B, Sterk G. Land management, erosion problems and soil and water conservation in Fincha'a watershed, western Ethiopia. Land Use Policy 2010;27(4):1027-37. DOI: https://doi.org/10.1016/jlandusepol.2010.01.005

16. Okolo CC, Gebresamuel G, Zenebe A, Haile M, Eze PN. Accumulation of organic carbon in various soil aggregate sizes under different land use systems in a semi-arid environment. Agric Ecosyst Environ 2020;297:106924. DOI: https://doi.org/10.1016/j.agee.2020.106924

17. Mamo Bahiru K. Enclosure as a viable option for rehabilitation of degraded lands and biodiversity conservation: the case of Kallu Woreda, Southern Wello. [thesis masters]. [Etiopía]: Addis Ababa University; 2008 [cited 2020 Oct 18]. Available from: http://213.55.95.56/handle/123456789/6185

18. Babulo B, Muys B, Nega F, Tollens E, Nyssen J, Deckers J, et al. The economic contribution of forest resource use to rural livelihoods in Tigray, Northern Ethiopia. For Policy Econ 2009;11(2): 109-17. DOI: https://doi.org/10.1016/j.forpol.2008.10.007

19. Lemenih M, Kassa H. Re-greening Ethiopia: history, challenges and lessons. Forests 2014;5:1896-909. DOI: https://doi.org/10.3390/f5081896

20. Mengistu T. The role of enclosures in the recovery of woody vegetation in degraded hillsides of biyo and tiya, central and northern Ethiopia [thesis masters]. Sweden: Ethiopian MSc in Forestry Programme thesis; 2005.

21. Muys B, Gebrehiwot K, Aerts R, Haile M, Deckers J. Perspectives for the rehabilitation of dryland forests in Ethiopia. J Dry-lands 2006;1(2):217-20.

22. Tilahun M, Olschewski R, Kleinn C, Kindeya G. Economic analysis of closing degraded Bosewellia papyrifera dry forest from human intervention-a study from Tigray, Northern Ethiopia. For Policy Econ 2007;9(8):996-1005. DOI: https://doi.org/10.1016/j.forpol.2006.09.004

23. Tekalign M. The role of area exclosures for biodiversity conservation and its contribution to local livelihoods: The case of Biyo-Kelala area exclosures in Ada`a Wereda [thesis masters]. [Addis Abeba]: Addis Ab-aba University; 2010 [cited 2020 Oct 18]. Available from: http://thesisbank.jhia.ac.ke/4115/

24. Veldkamp E, Mekuria W, Tilahun M, Olschewski R. Economic valuation of land res-toration: the case of exclosures established on communal grazing lands in Tigray, Ethiopia. Land Degrad Dev 2011;22:334-44. DOI: https://doi.org/10.1002/ldr.1001

25. Mulugeta G, Achenef M. Socio-Economic challenges of area exclosure practices: A case of Gonder Zuria Woreda, Amhara Region, Ethiopia. J Nat Sci Res 2015;5(13):123-32.

26. Dudley N, Higgins-Zogib L, Mansourian S. The links between protected areas, faiths, and sacred natural sites. Conserv Biol 2009;23(3):568-77. DOI: https://doi.org/10.1111/j.1523-1739.2009.01201.x

27. Birhane E. Actual and potential contributions of enclosures to enhance biodiversity in drylands of eastern Tigray, with particular emphasis on woody plants [thesis masters]. [Sweden]: Swedish University of Agricultural Sciences; 2002.

28. Heitschmidt RK, Vermeire LT, Grings EE. Is rangeland agriculture sustainable?. J Anim Sci 2004;82(E Suppl): E138-46. DOI: https://doi.org/10.2527/2004.8213_supplE138x

29. Manaye A. Contribution of exclosures for restoration of woody species diversity and regulating ecosystem services in Ethiopia. Environment and Forest Research Center: Mekele, Ethiopia. J Nat Sci Res 2017;7(13):28-35.

30. Mekuria W. Conversion of communal grazing lands into exclosures restored soil properties in the semi-arid lowlands of Northern Ethiopia. Arid Land Res Mang 2013;27(2):153-66. DOI: https://doi.org/10.1080/15324982.2012.721858

31. Gebregziabher D, Soltani A. Exclosures in people's minds: perceptions and attitudes in the Tigray region, Ethiopia. For Policy Econ 2019;101:1-14. DOI: https://doi.org/10.1016/j.forpol.2019.01.012

32. Amin A, Zaehringer JG, Schwilch G, Koné I. People, protected areas and ecosystem services: a qualitative and quantitative analysis of local people's perception and preferences in Côte d'Ivoire. Nat Resour Forum 2015;39(2):97-109. DOI: https://doi.org/10.1111/1477-8947.12069

33. Gebregziabher D, Soltani A, Hofstad O. Equity in the distribution of values of outputs from exclosures in Tigray, Ethiopia. J Arid Environ 2017;146 :75-85. DOI: https://doi.org/10.1016/j.jaridenv.2017.07.003

34. Soltani A, Angelsen A, Eid T. Poverty, forest dependence and forest degradation links: evidence from Zagros, Iran. Environ Dev Econ 2014;19(5):607-30. DOI: https://doi.org/10.1017/S1355770X13000648

35. Ostrom E. Self-governance and forest resources. Occasional Paper [Internet]. 1999 [cited 2020 Oct 10];20:2-15. Available from: https://www.cifor.org/publications/pdf_files/OccPapers/OP-20.pdf

Notes

Author notes

Alternative link

http://www.scielo.org.bo/scielo.php?script=sci_arttext&pid=S2308-38592021000200092&lng=es&nrm=iso (html)