Patterns Of Land-use Intensity Research Articles

SOCIOECONOMIC DRIVERS OF LAND USE INTENSIFICATION IN FIJI ISLANDS: A GEOGRAPHICAL APPROACH

Abstract. Shifting cultivation is a common agricultural practice in the Pacific Islands rarely sustainable today since fallow periods are ever shorter due to the demographic growth, farms fragmentation, uncertain land tenure, and pressures from the market economy among other factors (drivers). Official statistical data and maps were utilized to build up chloropleth maps indicating the areas of high land use intensity (LUI) according to farm size ranges and socioeconomic parameters (treatments) for the country. Twenty vector layers were digitized from published maps for eight ranges of farm sizes (from less than 1 to more than 100 ha), and converted to raster format with a 170 m2 pixel size. Critical maps were then built by boolean operations displaying areas in which both the land use and the socioeconomic driver were simultaneously ranked as high or very high. Treatments showed significant differences among them (p < 0.05), being the most influential those related to human demography. In farms smaller than 3 ha size land use is intense when (in order of importance) Indo-fijian population, household size and land availability values are high; while in farms of 20–50 ha size it is intense when the values of (in order of importance) population change, Indo-fijian population, land availability, fishing and sugar farming are also high. LUI patterns normally decrease with the increase of farm size, but increases on farms over 20 ha size. It is recommended to propose policies that will des-accelerate the rates of land use, such as the facilitation of land ownership over farms of bigger sizes, the gradual replacement of mono cropping by agroforestry systems, and the creation of more employment opportunities in the industry, tourism and services sectors.

Spatial and temporal dynamics of shifting cultivation in the middle-Amazonas river: Expansion and intensification

Shifting cultivation is the main land-use system transforming landscapes in riverine Amazonia. Increased concentration of the human population around villages and increasing market integration during the last decades may be causing agricultural intensification. Studies have shown that agricultural intensification, i.e. higher number of swidden-fallow cycles and shorter fallow periods, reduces crop productivity of swiddens and the regrowth capacity of fallows, undermining the resilience of the shifting cultivation system as a whole. We investigated the temporal and spatial dynamics of shifting cultivation in Brazilian Amazonia to test the hypotheses that (i) agriculture has become more intensive over time, and (ii) patterns of land-use intensity are related to land accessibility and human population density. We applied a breakpoint-detection algorithm to Landsat time-series spanning three decades (1984–2015) and retrieved the temporal dynamics of shifting cultivation fields, which go through alternating phases of crop production (swidden) and secondary forest regrowth (fallow). We found that fallow-period length has decreased from 6.4 to 5.1 years on average, and that expansion over old-growth forest has slowed down over time. Shorter fallow periods and higher frequency of slash and burn cycles are practiced closer to residences and around larger villages. Our results indicate that shifting cultivation in riverine Amazonia has gone through a process of agricultural intensification in the past three decades. The resulting landscape is predominantly covered by young secondary forests (≤ 12 yrs old), and 20% of it have gone through intensive use. Reversing this trend and avoiding the negative consequences of agricultural intensification requires land use planning that accounts for the constraints of land use in riverine areas.

Industrialization, urbanization and land use in China

Rapid industrial development and urbanization transfer more and more land away from agricultural production and affect the patterns of land use intensity. This paper analyzes the determinants of land use by modeling arable land and sown area separately. An inverse U-shaped relationship between land use intensity and industrialization is explored both theoretically and empirically. The findings highlight the conflict between the two policy goals of industrialization and grain self-sufficiency in the end. Several policy recommendations are offered to reconcile the conflict.

Plant species richness in grasslands: the relative importance of contemporary environment and land‐use history since the Iron Age

The richness of vascular plants in all patches of dry semi‐natural grassland within a landscape was investigated. The patch level richness was scaled up to the level of parish to match data on land‐use intensity from Iron Age through historical time. Three measures of diversity were obtained: the local species pool, an area‐independent diversity measure (the slope of the species number vs log area regression line), and the β‐diversity, A gradient through the study area in the density of grassland and a corresponding clinal variation in grassland plant species diversity were found. Explanatory models were built by partial least squares regression and conventional stepwise multiple regression. Data on contemporary environmental conditions in the grassland patches and in the parish as a whole were added first, and then data on continuously older times in sequence. In the stepwise regression analyses the variables were also added in the opposite sequence. The results show that contemporary conditions are able to explain the major part of the variation in all diversity measures. Variables concerning former land‐use do, however, add significantly to the explanation of variation in local species pool and in the area‐independent diversity, but not in β‐diversity. It is concluded that patterns of land‐use intensity from the Iron Age and onwards have contributed significantly to the shaping of local species pools, and thereby the richness of grassland communities.