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Abstract. Disturbances influence forest dynamics across a range of spatial and temporal scales. In tropical forests most studies have focused on disturbances occurring at small spatial and temporal scales (i.e., gap dynamics). This is primarily due to the difficulty of reconstructing long-term disturbance histories of forests in which most tree species lack annual growth rings. Consequently, the role of past disturbances in tropical forests is poorly understood. We used a combination of direct and indirect methods to reconstruct the historical disturbance regime and stand development patterns in mature and regenerating seasonal dry evergreen forest (SDEF) in the Huai Kha Khaeng Wildlife Sanctuary in western Thailand. Direct estimates of long-term establishment and growth patterns were obtained from 12 tree species that form annual growth rings as a consequence of the region's strong intra-annual rainfall seasonality. Indirect estimates of establishment patterns were obtained from analyses of stand structure and individual tree architecture and application of ageestimation models to 10 dominant canopy-tree species using demographic data from a largescale, permanent forest-dynamics plot.The combination of direct and indirect methodologies revealed a complex disturbance history in the seasonal evergreen forest over the past 250 years. In the mid-1800s, 200-300 ha of forest were destroyed by a catastrophic disturbance, which led to the synchronous establishment of many of the trees that presently dominate the forest canopy. Since then widespread disturbances of variable intensity have occurred at least three times (1910s, 1940s, and 1960s). These disturbances created discrete temporal pulses of establishment in small to large gaps in the forest matrix across several square kilometers. Background mortality and gap formation were evident in every decade since 1790, but these varied in intensity and frequency.The SDEF retains a distinct structural and floristic legacy from the catastrophic disturbance of the mid-1800s. The single-age cohort that established after the disturbance has developed a complex three-dimensional structure as a consequence of differences in interspecific growth patterns of the canopy-tree species and subsequent disturbances of moderate and low intensity. While no single methodological approach provided a complete picture of the disturbance history and stand development patterns of the seasonal evergreen forest, taken together they offered new insights into the long-term dynamics of a primary tropical forest. In particular, the study highlighted the role of disturbance at multiple spatial and temporal scales and varying intensities in determining the structure and composition of a complex, species-rich tropical forest and raises important questions about the role of rare, catastrophic events on tropical forest dynamics.

A 0.36—ha area in the Harvard Forest, Petersham, Massachusetts, was intensively analyzed to determine its history. Natural and man—caused disturbances of varying magnitudes occurred periodically in the central New England mixed—species stand. Evidence of two hurricanes and a fire prior to 1803 were found. Between 1803 and 1952, 14 natural or man—caused disturbances of various magnitudes occurred in the area. Large disturbances created new age classes, but small disturbances did not. Species arising together after large disturbances formed a distinct vertical stratification, with northern red oak (Quercus rubra L.) arising after several decades to the dominant canopy. Smaller disturbances to the overstory allowed understory trees such as black birch (Betula lenta L.), red maple (Acer rebrum L.), and eastern hemlock (Tsuga canadensis L. Carr.) to emerge to the dominant canopy. The composition of this forest was more the result of allogenic influences rather than autogenic development.

Context The Amur tiger and leopard, once roaming over the Eurasian continent, are now endangered and confined to the Sikhote-Alin Mountains, Russia-a landscape that has been increasingly fragmented due to human activities. The ultimate fate of these big cats depends on whether they can resettle in their previous main historical range in NE China. Recent sightings of these animals along the China-Russia border have aroused new hope, but direct evidence is lacking.Objectives The main objectives of our study were (1) to determine the abundance and spatiotemporal patterns of tigers, leopards, and primary prey; (2) to investigate factors influencing the resettlement of the two big cats; and (3) to propose a landscape-scale conservation plan to secure the long-term sustainability of the Amur tiger and leopard. Methods We monitored the two felids, their prey, and human activities, with 380 camera-trap stations, for a total of 175,127 trap days and over an area of 6000 km 2 in NE China. We used the constraint line method to characterize cattle grazing and human influences on tigers, leopards, and their prey species.Tianming Wang and Limin Feng contributed equally to this work.