Warfare rather than agriculture as a critical influence on fires in the late Holocene, inferred from northern Vietnam

Abstract

Fire has played an essential role in the development of human civilization. Most previous research suggests that frequent-fire regimes in the late Holocene were associated with intensification of human activities, especially agriculture development. Here, we analyze fire regimes recorded in the Song Hong delta area of Vietnam over the past 5,000 years. In the prehistoric period, 2 long-term, low-charcoal abundance periods have been linked to periods of low humidity and cool climate, and 5 short-term fire regimes of 100 -150 years in duration occurred at regular intervals of Ϸ700 years. However, over the last 1,500 years, the number, frequency, and intensity of fire regimes clearly increased. Six intensified-fire regime periods in northern Vietnam during this time coincided with changes of Vietnamese dynasties and associated warfare and unrest. In contrast, agricultural development supported by rulers of stable societies at this time does not show a positive correlation with intensified-fire regime periods. Thus, warfare rather than agriculture appears to have been a critical factor contributing to fire regimes in northern Vietnam during the late Holocene.fire regime ͉ Song Hong (Red River) ͉ charcoal ͉ human activities

Human impact overwhelms long-term climate control of weathering and erosion in southwest China

“…2000 cal yr B.P. (Li et al, 2009). Regardless of the exact cause of the intensified deforestation since 1800 cal yr B.P., the higher demand for natural resources was probably the ultimate reason for the trends described here.…”

“…Moreover, strengthened weathering and erosion and sulfurrelated metal element accumulation since 1800 cal yr B.P. coincide with evidence for intensified agriculture and early urbanization in the Red River basin (Li et al, 2009;Shen et al, 2006) ( Figs. 1 and 3E).…”

“…In contrast, high-resolution records spanning the Holocene are scarce (Bayon et al, 2012;Catalan et al, 2014;Hu et al, 2013); this time period is of particular interest for paleoclimate studies because it not only represents the most recent interglacial interval, but also one affected by anthropogenic processes (Bayon et al, 2012). Lake (Catalan et al, 2014;Shen et al, 2006) and deltaic cores (Hu et al, 2013;Li et al, 2009) have been used to reconstruct Holocene erosion and weathering rates to determine their relationship with climate and human activity. However, lake catchments are often local and delta sediment may be disturbed by reworking (Stanley and Hait, 2000).…”

Late Holocene Anthropogenic and Climatic Impact on a Tropical Island Ecosystem of Northern Vietnam

“…Information on the role of prehistoric human activities and climate change on northern Vietnam tropical environments is sparse. Paleoecological records that do exist for the region are reported for deltaic and estuarine environments, thus providing only broad-scale, regional, and continental interpretations (Li et al, 2006(Li et al, , 2009.…”

“…Early populations in the Red River Delta of northern Vietnam were relatively small and local rulers maintained the land, likely with limited impact on the environment (Taylor, 2014). Around 3000 years ago, rice cultivation and pond aquaculture expanded along the coast and major waterways as technology improved, populations expanded (Maloney, 1991;Chapuis, 1995;Li et al, 2009), and the coastline stabilized (Lam and Boyd, 2003;Tanabe et al, 2006). Fire has been employed extensively in northern Vietnam for rice cultivation to increase the number of crops each year (typically two) by burning stubble left after each harvest (Lasko et al, 2018).…”