4.2-kiloyear eventThe 4.2-kiloyear (thousand years) BP aridification event (long-term drought) was one of the most severe climatic events of the Holocene epoch. It defines the beginning of the current Meghalayan age in the Holocene epoch. Starting around 2200 BC, it probably lasted the entire 22nd century BC. It has been hypothesised to have caused the collapse of the Old Kingdom in Egypt as well as the Akkadian Empire in Mesopotamia, and the Liangzhu culture in the lower Yangtze River area.
SphagnumSphagnum is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of Sphagnum can store water, since both living and dead plants can hold large quantities of water inside their cells; plants may hold 16 to 26 times as much water as their dry weight, depending on the species. The empty cells help retain water in drier conditions.
Human impact on the environmentHuman impact on the environment (or anthropogenic environmental impact) refers to changes to biophysical environments and to ecosystems, biodiversity, and natural resources caused directly or indirectly by humans. Modifying the environment to fit the needs of society (as in the built environment) is causing severe effects including global warming, environmental degradation (such as ocean acidification), mass extinction and biodiversity loss, ecological crisis, and ecological collapse.
Landscape ecologyLandscape ecology is the science of studying and improving relationships between ecological processes in the environment and particular ecosystems. This is done within a variety of landscape scales, development spatial patterns, and organizational levels of research and policy. Concisely, landscape ecology can be described as the science of "landscape diversity" as the synergetic result of biodiversity and geodiversity.
LandscapeA landscape is the visible features of an area of land, its landforms, and how they integrate with natural or man-made features, often considered in terms of their aesthetic appeal. A landscape includes the physical elements of geophysically defined landforms such as (ice-capped) mountains, hills, water bodies such as rivers, lakes, ponds and the sea, living elements of land cover including indigenous vegetation, human elements including different forms of land use, buildings, and structures, and transitory elements such as lighting and weather conditions.
Early modern periodThe early modern period of modern history spans the period after the Late Middle Ages of the post-classical era (1400–1500) to the beginning of the Age of Revolutions (1800). Although the chronological limits of this period are open to debate, the timeframe is variously demarcated by historians as beginning with the fall of Constantinople in 1453, the Renaissance period in Europe and Timurid Central Asia, the end of the Crusades, the Age of Discovery (especially the voyages of Christopher Columbus beginning in 1492 but also Vasco da Gama's discovery of the sea route to India in 1498), and ending around the French Revolution in 1789, or Napoleon's rise to power.
Landscape archaeologyLandscape archaeology, a sub-discipline of archaeology and archaeological theory, is the study of the ways in which people in the past constructed and used the environment around them. It is also known as archaeogeography (from the Greek ἀρχαίος "ancient", and γεωγραφία "earth study"). Landscape archaeology is inherently multidisciplinary in its approach to the study of culture, and is used by pre-historical, classic, and historic archaeologists.
Early Middle AgesThe Early Middle Ages (or early medieval period), sometimes controversially referred to as the Dark Ages, is typically regarded by historians as lasting from the late 5th or early 6th century through the 10th century. They marked the start of the Middle Ages of European history, following the decline of the Western Roman Empire, and preceding the High Middle Ages ( 11th to 14th centuries). The alternative term late antiquity, for the early part of the period, emphasizes elements of continuity with the Roman Empire, while Early Middle Ages is used to emphasize developments characteristic of the earlier medieval period.
Proxy (climate)In the study of past climates ("paleoclimatology"), climate proxies are preserved physical characteristics of the past that stand in for direct meteorological measurements and enable scientists to reconstruct the climatic conditions over a longer fraction of the Earth's history. Reliable global records of climate only began in the 1880s, and proxies provide the only means for scientists to determine climatic patterns before record-keeping began. A large number of climate proxies have been studied from a variety of geologic contexts.
Primary successionPrimary succession is the beginning step of ecological succession after an extreme disturbance, which usually occurs in an environment devoid of vegetation and other organisms. These environments are typically lacking in soil, as disturbances like lava flow or retreating glaciers scour the environment clear of nutrients. In contrast, secondary succession occurs on substrates that previously supported vegetation before an ecological disturbance.
