As integral parts of terrestrial ecosystems, forest ecosystems conserve soil and water, sequester CO2, release O2, help purify the environment, mitigate hazards, mediate climate, and maintain biodiversity. These functions are crucial to life on earth. However, long-term forest exploitation due to human activities has caused serious problems such as biodiversity loss, decline in forest quality and stability, habitat fragmentation across forest landscapes, and decline in forest ecosystem services. These problems have threatened the integrity of ecosystems in China. To address these problems, IAE has been devoting attention to research on the structure, function, processes, and regulation of forest ecosystems designed to reveal the interactive mechanisms between forest and environment under global climate change and increasing human activities. We monitor and evaluate the ecological and environmental effects of state key projects such as the Natural Forest Protection Program, the Shelter Forest Program, and the Conversion of Cropland to Forest and Grassland Program. We also study the methods of optimizing the configuration of forest landscapes, develop theories and technical solutions for forest resource protection, management and restoration, and provide technical support for ecological construction in China.
In response to the need for ecological management and supporting research programs, IAE has identified the following three research foci in the area of Forest Ecosystem Functions — Sustainable Management: 1) Ecological processes and functions of natural forests; 2) Ecology and management of plantation forests; and 3) Forest landscape processes and controls.
1 Ecological Processes and Functions of Natural Forests
Natural forests are major components of forest resources with distinctive characteristics of rich biodiversity, high productivity and stability and sustainable ecological functions. Natural forests are complex ecosystems comprised of multiple species of different age cohorts. To examine their ecological processes and functions, we focus on the following research areas in the natural forests of Northeast China: (1) Mechanisms that maintain biodiversity in natural forests; (2) Approaches for improving ecological services of forest ecosystems; (3) Multiple objectives within sustainable management utilizing technologies based on digital forest management and decision support systems; and (4) Development of eco-boundary system theory and its applications in global climate change research. These studies help us to 1) better understand the biological and ecological characteristics of various tree species in natural forests, providing theoretical and technical support for biodiversity conservation; 2) understand the formative mechanisms of forest ecosystem services, and propose technological approaches for their management; 3) manipulate forest structure and optimize ecological functions; 4) construct digital forest management and decision support systems; and 5) reveal the mechanisms and effects of element cycles and energy fluxes in forest ecosystems.
2 Ecology and Management of Plantation Forests
Plantation forests account for about 7% of the world's forest area, some 264,000,000 ha, about a quarter of which are found in China. These forests have become crucial to solving problems such as shrinkage of forest areas, loss of biodiversity and degradation of forest environments. Based on their primary functions, plantation forests in China can be roughly divided into timber production forests and shelter forests. Due to the need for extensive management and lack of theories and technologies related to management of these forests, plantation forestry in China is far less sophisticated than its practice in developed countries. Consequently, degradation and decline in ecological service functions challenge the management of these forests.
How to improve the ecological services and productivity of plantation forests through scientific management is the major challenge for plantation forest research. The roles of plantation forests in the global carbon budget have become an important research focus in this area. Utilizing current domestic and international research, and taking national needs into account, we focus on: (1) Mechanisms and restoration processes of degraded plantation forests; (2) Prescriptions and technologies for management of Three North Shelter-forests; and 3) Carbon cycle processes in plantation forests.
3 Forest Landscape Processes and Controls
Landscape processes are major forces driving landscape change and shaping landscape pattern. They are one of the core areas of landscape ecological research. Forest landscape processes are spatially explicit, temporally discrete natural and anthropogenic processes including seed dispersal, seed migration, forest fire, windthrow, harvesting, tree planting, and insect and disease outbreaks. They operate at large spatial (1,000–1,000,000 ha) and temporal (10–1,000 years) scales. They are the key processes that drive the dynamics, pattern, productivity, and biodiversity of forest ecosystems. Contemporary research on landscape composition (e.g., land cover types or dominant species) and function (e.g., ability to sequester carbon) in response to climate change emphasizes the direct impact of warming climate while paying less attention to the effects on forest landscape processes. Recent studies suggest that the effects of these processes on landscape pattern and function are non-negligible and can be larger than the direct effects of climate warming. This is especially true for forest landscapes in Northeast China, where fire and harvesting are predominant landscape processes. Regional predictions of total forest carbon under changing climate will have a high degree of uncertainty without considering the effects of these processes. Thus, how to incorporate forest landscape processes in forest ecosystem studies, how to study the response of those processes to climate change at regional scales, and how to control landscape processes are important research areas in landscape ecology and global change ecology. These issues require immediate attention with respect to forest industry and sustainable forest management in China.
Based upon our previous research and future directions, the focal area of forest landscape processes and controls has the following priorities: 1) Forest landscape modeling; 2) Effects of ecological processes on forest landscapes; 3) Urban forest structure and function; and 4) Urban planning and forest landscape design. Specifically, we will target forest ecosystems of Northeast China, utilizing integrated approaches of field inventory, landscape modeling, remote sensing, GIS, and spatial statistics to address the following research questions: 1) How pattern, function, and ecological benefits of forests in urban and natural landscapes will change in Northeast China; 2) How climate change and forest landscape processes interactively affect and control forest landscape change and functions; and 3) How to improve forest ecosystem functions and mitigate the potentially negative effects of climate change through effective urban planning and forest management.