Long-term loblolly pine aboveground growth, canopy dynamics, and economic implications from throughfall exclusion, fertilization, and thinning in southeastern Oklahoma, USA

Loblolly pine (Pinus tadea L.) is the most commercially important timber species in the southern USA. Climate change induced drought, due to longer periods without rainfall, will alter forest growth in the region. Loblolly pine occurs on 21 million ha in the southeast and represents 87% of the regions timber production. The species productivity is likely to face new tests as climate change makes growing conditions more adverse. How climate change might affect common silvicultural practices, like fertilization and thinning, that typically increase stand productivity, is not known. This study, located in the more xeric southeastern Oklahoma, aimed to understand if a plantation regime shift could occur under drier conditions from a growth and efficiency standpoint. A 30% throughfall reduction (drought) treatment from age 5 to 12, fertilization at age 5 and 10, and thinning at age 10 were examined. From stand age 5 to 12, drought treatment decreased standing volume by 7% and fertilization increased standing volume by 8%, offsetting one another, and thus fertilization compensated for potential drought conditions. Additionally, drought-induced plots had +10% basal area growth after meteorological drought conditions subsided. Under current management strategies and potential compensatory growth, loblolly pine plantations appear to be sustainable under a drier climate. Further, efficiency analysis was leveraged to examine all treatment's ability to turn volume growth and stand density into timber products, i.e., pulpwood, chip-n-saw, and sawtimber, at 21, 26, and 31 rotation ages. At all rotation ages, fertilized-thinned stands were perfectly efficient, yet overall fertilization had no effect, and showed negative synergistic interactions with drought (-24% efficient). Thinning had the greatest ability to maintain effective production; non-thinned stands demonstrated a 32% decrease in efficiency. Drought treatment decreased efficiency by 11% after 26 years. Efficiency scores support thinning as a regime staple and fertilization to be ineffective in the long-term. Together, growth analysis supports fertilization to biologically compensate for drought, but efficiency analysis suggests fertilization unable to compensate on a resource-use basis

The genetic history of the Southern Arc: a bridge between West Asia and Europe

By sequencing 727 ancient individuals from the Southern Arc (Anatolia and its neighbors in Southeastern Europe and West Asia) over 10,000 years, we contextualize its Chalcolithic period and Bronze Age (about 5000 to 1000 BCE), when extensive gene flow entangled it with the Eurasian steppe. Two streams of migration transmitted Caucasus and Anatolian/Levantine ancestry northward, and the Yamnaya pastoralists, formed on the steppe, then spread southward into the Balkans and across the Caucasus into Armenia, where they left numerous patrilineal descendants. Anatolia was transformed by intra–West Asian gene flow, with negligible impact of the later Yamnaya migrations. This contrasts with all other regions where Indo-European languages were spoken, suggesting that the homeland of the Indo-Anatolian language family was in West Asia, with only secondary dispersals of non-Anatolian Indo-Europeans from the steppe

The genetic history of the Southern Arc. A bridge between West Asia and Europe

By sequencing 727 ancient individuals from the Southern Arc (Anatolia and its neighbors in Southeastern Europe and West Asia) over 10,000 years, we contextualize its Chalcolithic period and Bronze Age (about 5000 to 1000 BCE), when extensive gene flow entangled it with the Eurasian steppe. Two streams of migration transmitted Caucasus and Anatolian/Levantine ancestry northward, and the Yamnaya pastoralists, formed on the steppe, then spread southward into the Balkans and across the Caucasus into Armenia, where they left numerous patrilineal descendants. Anatolia was transformed by intra-West Asian gene flow, with negligible impact of the later Yamnaya migrations. This contrasts with all other regions where Indo-European languages were spoken, suggesting that the homeland of the IndoAnatolian language family was in West Asia, with only secondary dispersals of non-Anatolian IndoEuropeans from the steppe

A genetic probe into the ancient and medieval history of Southern Europe and West Asia

Literary and archaeological sources have preserved a rich history of Southern Europe and West Asia since the Bronze Age that can be complemented by genetics. Mycenaean period elites in Greece did not differ from the general population and included both people with some steppe ancestry and others, like the Griffin Warrior, without it. Similarly, people in the central area of the Urartian Kingdom around Lake Van lacked the steppe ancestry characteristic of the kingdom's northern provinces. Anatolia exhibited extraordinary continuity down to the Roman and Byzantine periods, with its people serving as the demographic core of much of the Roman Empire, including the city of Rome itself. During medieval times, migrations associated with Slavic and Turkic speakers profoundly affected the region

A genetic probe into the ancient and medieval history of Southern Europe and West Asia

Literary and archaeological sources have preserved a rich history of Southern Europe and West Asia since the Bronze Age that can be complemented by genetics. Mycenaean period elites in Greece did not differ from the general population and included both people with some steppe ancestry and others, like the Griffin Warrior, without it. Similarly, people in the central area of the Urartian Kingdom around Lake Van lacked the steppe ancestry characteristic of the kingdom’s northern provinces. Anatolia exhibited extraordinary continuity down to the Roman and Byzantine periods, with its people serving as the demographic core of much of the Roman Empire, including the city of Rome itself. During medieval times, migrations associated with Slavic and Turkic speakers profoundly affected the region

A genetic probe into the ancient and medieval history of Southern Europe and West Asia

Literary and archaeological sources have preserved a rich history of Southern Europe and West Asia since the Bronze Age that can be complemented by genetics. Mycenaean period elites in Greece did not differ from the general population and included both people with some steppe ancestry and others, like the Griffin Warrior, without it. Similarly, people in the central area of the Urartian Kingdom around Lake Van lacked the steppe ancestry characteristic of the kingdom's northern provinces. Anatolia exhibited extraordinary continuity down to the Roman and Byzantine periods, with its people serving as the demographic core of much of the Roman Empire, including the city of Rome itself. During medieval times, migrations associated with Slavic and Turkic speakers profoundly affected the region

Ancient DNA from Mesopotamia suggests distinct Pre-Pottery and Pottery Neolithic migrations into Anatolia

We present the first ancient DNA data from the Pre-Pottery Neolithic of Mesopotamia (Southeastern Turkey and Northern Iraq), Cyprus, and the Northwestern Zagros, along with the first data from Neolithic Armenia. We show that these and neighboring populations were formed through admixture of pre-Neolithic sources related to Anatolian, Caucasus, and Levantine hunter-gatherers, forming a Neolithic continuum of ancestry mirroring the geography of West Asia. By analyzing Pre-Pottery and Pottery Neolithic populations of Anatolia, we show that the former were derived from admixture between Mesopotamian-related and local Epipaleolithic-related sources, but the latter experienced additional Levantine-related gene flow, thus documenting at least two pulses of migration from the Fertile Crescent heartland to the early farmers of Anatolia