Rueff, H. 123, I. Rahim3, R. Khurshid3 & D. Maselli4
1School of Geography and the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY, United Kingdom; 2Centre for Development and Environment, University of Bern, Hallerstrasse 10, Bern 3012, Switzerland; 3Foundation for Research and Socio-Ecological Harmony, House #41, street 32, sector D17/2, Islamabad, Pakistan; 4Swiss
Agency for Development and Cooperation, Freiburgstrasse 130, Bern 3003, Switzerland.
Introduction
Crop encroachment over pastures is a global issue that affected the sustainability of pastoral systems and the livelihood of nomadic herders at risk. In the Pakistani Hindu Kush Himalayas, the degradation of high altitude rangelands occurs as pastoralists till pastures on steep slopes to crop off-season potatoes and peas. While during the first year of cropping the reward is much higher than keeping livestock, soil loss due to the lack ofterracing fosters a rapid yield decline (Khan et al., 2012; Harden, 1991). Resorting to evermore fertilizers as well as further reclaiming plots at higher elevation exacerbates pressure over pastures and herders who still keep livestock.
We analyse the socio-ecological impacts of crop encroachment in the mountain context of the Naran Valley in the Pakistani Himalayas and analyse a potential payment scheme compensating for the renouncement of cropping based on the REDD+ principles for avoided emissions (Tennigkeit & Wilkes, 2008). We posit that, by shrinking the available grazing area, crop encroachment leads to a reduction in herd size, changes in herd composition, and alterations of family labour divisions. It also compels sheep and goat herds to graze on higher elevation pastures and for longer durations. We further hypothesize that cropping over pastures reduces carbon (C) stores, and that avoide demissions from preventing the conversion of pastures into cropping fields may yield more C payment than conventional improved pasture mitigation activities.
Methodolgy
The study area located in the Naran valley (34.48°-34.55° North and 73.51°-74.02° East) of the Pakistani Himalayas receives an annual average of 819 mm of rain and 764 mm of snow.
Average temperatures remain below 0°C from November to March while frost may occur all year round. A geographic information system (GIS) was used to assess the extent of crop encroachment since the last 25 years discriminating for the extension intime, elevation and slope inclination and by means of mapping global positioning system way points. A questionnaire was administered to 126 respondents previously selected using participatory rural appraisal and divided in four groups: Group A herding sheep and goats as the sole occupation, Group B herding sheep and goats with occasional labour service in cropping, Group C engaged both in cropping and herding, Group D engaged mainly in cropping with only a few cattle for homestead milk. A paired t-Test between the current and 25 years back
133
situations was used to assess the impact of crop encroachment on herd size, herd composition and herding labour allocation.
A total of 72 soil core samples were collected discriminating land use (cropping, pasture), aspect (North, South), elevation (low 3000, middle 3100, and high 3200 ma.s.l.), and soil depth (shallow 0-10, deep 10-30 cm). Thirty six biomass samples were collected over the same independent variables (except for soil depth) using a 10x10x20cm steal box inserted in the ground for each sample. Above ground biomass and coarseroots were separated from the soil aggregate and oven-dried. Soil organic carbon (SOC) and biomass carbon (BC) were estimated through a potassium dichromate oxidation treatment. The samples were collected during the second week of October 2010 at the end of the grazing and cropping season and before the first snowfall. The data was statistically analyzed by means of a one-way analysis of variance.
Results
The GIS analysis shows that crop encroached on 3% of the grazing areas, mostly on prime pastoral niches. Cropping reduced herd sizes by at least 47%, halved the number of small ruminants, and shifted more than half of the family labour away from herding. Furthermore, sheep and goat herds increasingly have to graze at higher elevations for longer periods, despite a shorter plant growth period on those pastures. Although highly rewarding in the short run, crop encroachment endangers this pastoral system as the tilling of ever steeper plots causes the loss of soil and nurtures land abandonment.
Table 1. Distribution of crop encroachment by elevation and degrees of slope.
The one-way analysis of variance on mean soil organic C shows that all variables taken separately have a significant effect (P<0.01) (n=72) [g kg-1]: (land use) crop/pasture13.3/15.9, (aspect) North/South 16.1/13.2, (elevation) low/middle/high 10.9/16.2/16.8,(soil depth) shallow/deep 1.4/1.53. These preliminary findings suggest that preventing the conversion of pastures into cropping fields in the Naran valley avoids an average loss of 12.2 t C ha-1or 44.8 t CO2eq ha-1representing a foreseeable compensation of 672€ ha-1for the Naran landless pastoralists who would renounce cropping.
Conclusions
Although highly rewarding in the short run, crop encroachment endangers this pastoral system as the tilling of ever steeper plots causes the loss of soil and nurtures land
134
abandonment. The ongoing study shall provide a complete picture for carbon payment integrating key aspects such as the rate of cropping encroachment over pastures per year,the methane leakage from the system due to livestock enteric fermentation, the expected cropping income vs. livestock income and the transaction costs of implementing themitigation project, certifying it, and verifying carbon credits.
Acknowledgments
This study was conducted within the framework of the Joint Research Partnership fundedby the Swiss National Science Foundation (SNSF) and the Swiss Agency forDevelopment and Cooperation (SDC). It was also conducted within the framework of the Swiss National Centre of Competence in Research (NCCR) North–South: Research Partnerships for Mitigating Syndromes of Global Change. The NCCR North–South is co-funded by SNSF and SDC, and the participating institutions.
References
Khan, S. M., S. Page, H. Ahmad, and D. Harper. 2012. Anthropogenic influences on the natural ecosystem of the Naran valley in the western Himalayas. Pakistan J. Bot. 44:
231-238
Harden, C. P., 1991. Soil erosion and sustainable mountain development experiments observations, and recommendations from the Ecuadorian Andes. Mt. Res. Dev. 21: 77- 83
Tennigkeit, T. and A. Wilkes. 2008. Carbon Finance in Rangelands: An Assessment of Potential in Communal Rangelands. Nairobi: World Initiative for Sustainable Pastoralism– IUCN. pp29
135 Oral 2