Toshiya Okuro

Indigenous ecological knowledge and natural resource management in the cultural landscape of China’s Hani Terraces

Indigenous ecological knowledge (IEK) can contribute to the management of local ecosystems and landscapes. Cultural landscapes are produced by and reflect the long-term interactions between humans and nature in indigenous societies. Yunnan Province, located in southwestern China, is the homeland of many ethnic groups, and is also a refuge for numerous species of wild plants and animals. Indigenous people in Yunnan, who have rich ecological knowledge, play an important role in the conservation of local biodiversity and the region’s unique terraced agricultural landscapes. We used the Hani people and their outstanding cultural landscape of rice terraces in Yuanyang County of Yunnan Province as a case study to describe their worldview and discuss their formation of IEK; their roles in the preservation of rice landraces and in pest regulation; their management of water, forest, and soil resources; and the vertical landscape pattern and resource-circulation system that has evolved in the areas managed by the Hani. We also discuss the challenges and threats facing the Hani, their IEK, and their cultural landscape, as well as discuss the potential for integration of the Hani’s IEK with modern conservation efforts.

Threshold Distinctions Between Equilibrium and Nonequilibrium Pastoral Systems Along a Continuous Climatic Gradient

Abstract In equilibrium environments where rainfall is relatively stable, grazing animal–vegetation dynamics are density-dependent; it is therefore appropriate to calculate carrying capacities and use them to define sustainable animal populations. In contrast, nonequilibrium environments are characterized by fluctuations in characteristics such as rainfall, resulting in fluctuations in plant biomass and in the corresponding carrying capacity. Herders adapt to such environments by moving opportunistically to pastures with better conditions. Studies since the 1990s have significantly improved our understanding of the continuity and integration of equilibrium and nonequilibrium systems. However, it remains unclear how and where such continuous, integrated rangeland systems result in qualitatively different land use patterns by local herders along a climatic gradient. Here, we developed a simple model that uses key environmental factors to predict a threshold representing the boundary between equilibrium and nonequilibrium land use systems, and we used an area of Mongolian rangeland as an example. We found a threshold in the proportion of usable pasture that corresponded to a specific range of rainfall values. Comparison of our results with previous ones supported our hypothesis about this threshold. The threshold behavior suggested that it is important to identify and monitor the boundary between equilibrium and nonequilibrium land use systems so that managers can respond to climatic change. National governments and aid agencies must understand the threshold process before they can identify focal areas where management regime change is required and propose appropriate policies that will support herders in the long term. Our study provides a simple, low-cost tool to evaluate ecosystems in this context.

The potential of, and threat to, the transfer of ecological knowledge in urban areas: the case of community-based woodland management in Tokyo, Japan

Urban dwellers often have little knowledge of local ecosystems, but community groups that actively manage local ecosystems can acquire a rich ecological knowledge. Understanding the knowledge transfer process within community groups contributes to the continuous improvement of urban ecosystem management. In this paper, we address three main questions: (1) How is ecological knowledge acquisition linked to boundary and intra-group interactions? (2) Does holding knowledge mean the involvement in actual management activities? (3) Does the aging of community group members threaten the continuity of activities? We selected satoyama woodlands (seminatural woodlands) in peri-urban Tokyo, Japan as a study site. We used a mixed method approach that combined a qualitative interview with a quantitative questionnaire. We found that boundary interactions were particularly important at the start of an urban ecological management process, to obtain basic knowledge relating to management activities. Intra-group interaction contributed to knowledge transfer after the starting period. We found that participants possessing considerable ecological knowledge do not necessarily participate in management activities. Findings also indicated that the aging of group members in groups established for more than 10 years was an area of concern for the continuity of group activities. New members did not necessarily solve this aging issue. We conclude that further measures and actions are needed to ensure long-term knowledge transfer among the participants of community groups in urban ecosystem management.

Degraded rangeland dominated by unpalatable forbs exhibits large-scale spatial heterogeneity

The spatial heterogeneity of vegetation and soil increases in response to land degradation caused by grazing mainly at a large spatial scale. This increase has been frequently associated with shrub invasion, but shrub invasion does not necessarily accompany land degradation. Instead, dominance by unpalatable forbs has been reported in some regions, but the spatial heterogeneity of such degraded rangeland has not been studied. We investigated the spatial heterogeneity of rangeland dominated by unpalatable forbs at a large spatial scale using Mongolian rangeland as an example. Spatial heterogeneity of the total vegetation cover and community heterogeneity were analyzed for three levels of land degradation. We found that the least-degraded site had homogeneous total vegetation cover and community, that the site with intermediate degradation exhibited low heterogeneity of the total vegetation cover but significant community type variation, and that the most degrade sites exhibited a periodic pattern of total vegetation cover as a result of a mixture of dense and sparse patches of unpalatable forbs. These different responses can be used to assess land degradation levels and may have potential to monitor land degradation at a large scale by satellite images.

Detection of vegetation trends in highly variable environments after grazing exclusion in Mongolia

Question Environmental variability (e.g., in precipitation) has a large effect on vegetation dynamics, and this often makes it difficult to assess the recovery of vegetation after a disturbance. In this study, we assessed vegetation recovery trends in response to grazing exclusion while considering for the annual environmental variability. Location Two regions with highly variable precipitation: a steppe near Mandalgobi (45°46′N, 106°16′E), in Mongolias Central Gobi province, and a desert steppe near Bulgan (43°54′N, 103°31′E), in Mongolias South Gobi province. Changes in vegetation were observed along grazing gradients at these two sites, and vegetation thresholds were identified. Methods We established reference plots in pre-threshold areas along the grazing gradients. We removed the impact of livestock grazing at various locations along the grazing gradients by establishing exclosures, and investigated vegetation from 2005 through 2013. We developed a smoothed hierarchical model within a Bayesian framework, and examined the effect of grazing exclusion on vegetation, focusing especially on the extent of grass cover recovery. In addition, we compared soil nutrient conditions in the reference plots and inside and outside each exclosure along the grazing gradients. Results Temporal trends in the cover of perennial grass in each plot inside and outside of the exclosures largely coincided, irrespective of grazing intensity, and exclosure had no effect (Bulgan) or a negative effect (Mandalgobi) on vegetation recovery. Soil nutrient content was not significantly affected by exclosure at a given distance from the grazing source, but decreased significantly with decreasing grazing intensity. Thus, recovery of the land from a post-threshold state may not be apparent even after 9 years of grazing exclusion in environments with highly variable precipitation. Conclusion The effect of exclosure duration on perennial grass cover was limited, even after controlling for environmental variability. Once a vegetation threshold has been crossed, merely removing livestock from the landscape may not be sufficient for that area to recover. This article is protected by copyright. All rights reserved.

Role of tussock morphology in providing protection from grazing for neighbouring palatable plants in a semi-arid Mongolian rangeland

Background: Palatable plants in rangelands may be protected from herbivore grazing by the presence of less palatable neighbouring plants. The protective role of benefactor species on palatable species often collapses under heavy grazing, but the underlying mechanism—the relationship between the reduced protective role and grazing damage to benefactor species—remains unclear. Aims: To clarify whether the protection of surrounding palatable species conferred by a less palatable tussock grass (Achnatherum splendens) is reduced under heavy grazing, focusing on the changes to tussock morphology caused by grazing. Methods: In the Mongolian steppe, we measured the morphological traits of A. splendens tussocks, plant density of palatable graminoids and grazing damage in three A. splendens microhabitats (inside, adjacent to, and outside tussocks) under light and heavy grazing areas. Results: A. splendens tussocks had smaller basal area and culm height, and greater culm density under heavy grazing. The densities of palatable graminoids adjacent to and inside tussocks were equal to or lower than those outside, but grazing damage decreased inside tussocks. Additionally, plant establishment inside tussocks was negatively related to A. splendens culm density, probably owing to competition for space within the tussocks. Conclusions: Our results indicate that the collapse of positive grass–grass interactions results from the decline in neighbouring benefactor plants through the morphological changes caused by grazing.

Ecosystem Services and Biodiversity of Traditional Agricultural Landscapes: A Case Study of the Hani Terraces in Southwest China

The traditional agricultural landscape has many ecosystem services as well as a rich biodiversity. This paper analyzes the multiple ecosystem services provided by the Hani Terrace landscape in southwestern China. The results indicate: the Hani Terrace landscape is a traditional sustainable rice agriculture landscape which has multiple ecosystem services and a rich biodiversity that are generated from the close relationships between the landscape elements/ecosystems that are maintained by local farmers. However, although the Hani Terrace landscape has almost maintained its original status, it is facing continuous pressures from social and economic development so adequate adaptive management strategies should be developed to meet the challenges.

Relationship Between Pastoralists’ Evaluation of Rangeland State and Vegetation Threshold Changes in Mongolian Rangelands

Abstract Applying the threshold concept to rangeland management is an important challenge in semi-arid and arid regions. Threshold recognition and prediction is necessary to enable local pastoralists to prevent the occurrence of an undesirable state that would result from unsustainable grazing pressure, but this requires a better understanding of the pastoralists’ perception of vegetation threshold changes. We estimated plant species cover in survey plots along grazing gradients in steppe and desert-steppe areas of Mongolia. We also conducted interviews with local pastoralists and asked them to evaluate whether the plots were suitable for grazing. Floristic composition changed nonlinearly along the grazing gradient in both the desert-steppe and steppe areas. Pastoralists observed the floristic composition changes along the grazing gradients, but their evaluations of grazing suitability did not always decrease along the grazing gradients, both of which included areas in a post-threshold state. These results indicated that local pastoralists and scientists may have different perceptions of vegetation states, even though both of groups used plant species and coverage as indicators in their evaluations. Therefore, in future studies of rangeland management, researchers and pastoralists should exchange their knowledge and perceptions to successfully apply the threshold concept to rangeland management.

Effects of Changes in Soil Hydraulic Properties after Crop Abandonment on Co-Occurring Perennial Species in a Semi-Arid Grassland in Mongolia

18 The objective of this study was to investigate successional changes in water flow as a 19 result of changes in soil hydraulic properties after crop abandonment under drought and non20 drought conditions, and under water uptake by co-occurring perennial plant species to clarify the 21 observation that typical perennial grass species are seldom observed in abandoned fields. Soil 22 hydraulic properties were measured in croplands which had been abandoned for different periods (2, 23 9, and 18 years from abandonment) and in a grazed grassland site. Hydrological processes in the 24 soil profiles were simulated with soil hydraulic properties under drought and non-drought summer 25 conditions with water uptake from perennial grass species Suction in the surface soils increased 26 with the period of abandonment, with this trend being particularly obvious in a drought year. 27 Available water appears to be restricted in the later successional stage of abandoned fields and in 28 grazed grassland for plants that have drought tolerance. Dry soil and climate conditions are 29 important factors determining the intrusion of the typical perennial grass, S. krylovii, into degraded 30 abandoned fields. This abiotic interaction between soil hydraulic properties and climate conditions 31 may play an important role for plant succession in abandoned cropland. 32 33

Prescribed burning experiments for restoration of degraded semiarid Mongolian steppe

Prescribed burning has been a successful ecosystem restoration tool worldwide. In this study, we burned two different degraded Mongolian grasslands in spring: sparsely vegetated Argalant (ARG) and Hustai National Park (HNP), dominated by the unpalatable forb Artemisia adamsii. We investigated soil properties, seed bank, seedling density, vegetation, biomass, and forage quality before and/or after burning in the grasslands. Burning weakly affected soil properties and significantly reduced seed bank density. Seedling density of Chenopodium aristatum was greater and that of Cleistogenes squarrosa was lower in burned than in unburned plots of HNP, although C. squarrosa showed greater vegetative growth in burned plots. The floristic composition showed small changes after burning, depending on the pre-burning vegetation, but cover of A. adamsii decreased after burning in both ARG and HNP. Thus, the reduced seed bank density by burning led to weak responses of vegetation composition to burning due to strong vegetative growth. However, burning suppressed the unpalatable forb (A. adamsii) and hastened palatable grass (C. squarrosa) productivity, which would be attractive for livestock production, especially for overgrazed areas with low forage palatability. Our findings illustrate the possibility of using spring prescribed burning as a restoration tool in degraded Mongolian steppe, as well as the importance of site-specific conditions for understanding postfire recovery.