Spatial explicitness and spatial analysis are the methodology and technology systems to study spatial pattern and process based on the Remote Sensing (RS), Geographic Information System (GIS) and Spatial Modeling Systems (SMS). There are a lot of works regarding the spatial explicitness and analysis application in ecology, especially in landscape ecology since 1970s. In general, the spatial explicitness and analysis of ecosystem succession and restoration are to study the spatial pattern of ecosystem succession; to identify the disturbance area, severity and frequency; to estimate the change direction and change rate under disturbance; to illustrate the fragmentation of landscape pattern associate with ecosystem succession; to assess the potential capacity of natural restoration of degraded ecosystem; to evaluate the suitability of ecosystem restoration in landscape and regional scale.

In this presentation, we will address four issues regarding the spatial explicitness and analysis of ecosystem succession and restoration. (1).spatial explicitness and analysis of disturbance; (2). spatial explicitness and analysis of ecosystem succession ; (3). spatial explicitness and analysis of degradation and restoration of ecosystem; (4). spatial explicitness and analysis of history, current and future change of ecosystem patterns in large temporal and spatial scales.

Disturbance regimes usually caused the changes of ecosystem. Fire, pest, harvesting, wind throw, and flood are principle disturbance factors in most biomes of world. The spatial explicitness will recognize and locate the disturbance sites, areas, severity, and frequency. The spatial analysis will analyze the relationship among the disturbance and environmental gradient, climate change, and human activities. Therefore, it provided the basic information relevant to the degradation of ecosystem caused by disturbance.

Ecosystem succession usually is the temporal seral along the environmental gradient, and achieves a mono-climax or a poly-climax in the end. We can identify the spatial distribution pattern and area, associate with pioneer, transition, and climax stages of ecosystem succession using the spatial explicit methodology, and to analyze the fragmentation and mosaic of ecosystem succession spatial patterns, as well as the relationship among the succession spatial pattern formed with the environmental gradient and anthropocentric factors by spatial analysis.

The degradation of ecosystem, for example, the damaged degree and extent, as well as the health quality of ecosystem can be well explicited and analyzed using spatial technology. We also can identify the restoration direction, rate, area and stages of degradation ecosystem using the spatial explicitness and analysis, thus, it can be used to support the restoration practice and decision – making for ecosystem sustainability.

In relatively large temporal scales (for instance, hundreds of years), the reconstruction of historical ecosystem spatial pattern, and the projecting of future ecosystem spatial pattern under climate changes, as well as the comparison with present spatial pattern are insight into the ecosystem succession seral and patterns. The spatial explicitness and analysis are the important and fundamental methodology to realize the data compilation, integration, mapping and analysis.

The case studies of spatial explicitness and analysis of ecosystem succession and restoration present in here based on our study results in Canadian boreal forests and temperate forests of Pacific Northwest (PNW), USA.

Case study one shows the identification of fire, harvest and forest pest disturbance spatial patterns, and analyzed the effects of environmental and anthropocentric impacts in Canadian boreal forests and temperate forest of PNW-USA. The spatial patterns of disturbance were explicated using the satellite and aerial remote sensing and GIS. We also analyzed the spatial pattern of disturbance and the relationship between disturbance (pest and fire) and the environmental gradients (e.g. elevation and climate), the vegetation types and succession.  Our findings are that fire and pest disturbance closely relevant to the vegetation succession, the late seral forests suppressed the fire and pest impacts.

Case study two shows the spatial explicitness and analysis of ecosystem succession, and pattern associated with environment and forest management in boreal forests transect of central Canada, as well as temperate forests of PNW, USA. In boreal forest transect, we explicated the vegetation succession patterns along the gradient from southern aspen parkland to northern sub-arctic boreal woodlands in central Canada. We found the wild fire play a critical role to produce the spatial mosaic pattern of boreal forests succession along the transect. In PNW-USA, the late seral  forests succession patterns were analyzed, and discovered the elevation gradient, public and private land and protected area have different effects on the succession dynamics.

In case study three, we show the results of spatial explicitness and analysis on vegetation natural restoration after fire disturbance in Klamath Siskiyou mountain of Northern California, USA. In 1987, wild fire burned a lot of vegetation in this region. We used the Landsat TM (ETM+) remote sensing imagery of 1986, 1988 and 2000, studied the vegetation succession patterns under fire disturbance and natural restoration. The spatial analysis also was carried out through the application of spatial fragmentation analysis and spatial autocorrelation to explain the natural restoration direction, rate and extents.

Case study four show a spatial explicitness and analysis of ecosystem succession in large temporal and spatial scale used in recovery of the history vegetation of pre-settlement of European, current vegetation, and the future vegetation under climate changes in North American. Historical vegetation spatial pattern was compiled based on the historical map, data and pollen records, current vegetation is based on the AVHRR, MODIS and Landsat TM remote sensing imagery classification, future vegetation (about year 2080) is the simulation result by MAPSS model. From the comparison of vegetation spatial patterns in different periods, we discussed the effects of climate change, natural and anthropocentric disturbance on the large scales change of ecosystems. 

Overall, our results indicated that the spatial explicitness and spatial analysis using remote sensing, GIS and spatial modeling are useful and important methodology to study the ecosystem succession and restoration, especially in landscape, regional, continental, and even global scales.

Key words: spatial explicitness; spatial analysis; disturbance; ecosystem succession; ecosystem restoration