Kenneth R Young

University of Texas at Austin | UT · Department of Geography and The Environment

While the grazing of livestock has occurred for millennia in the Andes, current sustainability debates center on concerns with co-managing climate change and pastoralism. These discussions have special resonance in places protected by the state for biodiversity, scenery, and sustainable and traditional land uses, such as those found in protected ar...

The rapid expansion of avocado cultivation in Michoacán, Mexico, is one of the drivers of deforestation. We assessed the degree of fragmentation and functional connectivity of the remaining temperate forest within the Avocado Belt and prioritized patches that contribute the most to connectivity using a network-based approach and modelling different...

Tree diversity and composition in Amazonia are known to be strongly determined by the water supplied by precipitation. Nevertheless, within the same climatic regime, water availability is modulated by local topography and soil characteristics (hereafter referred to as local hydrological conditions), varying from saturated and poorly drained to well...

Humans place strong pressure on land and have modified around 75% of Earth’s terrestrial surface. In this context, ecoregions and biomes, merely defined on the basis of their biophysical features, are incomplete characterizations of the territory. Land system science requires classification schemes that incorporate both social and biophysical dimen...

As demand for avocado climbs, avocado production in Michoacán - Mexico’s biggest avocado growing region - expands into new places. We use a spatial probit model to project the geographic distribution of likely future avocado expansion and analyze those results to determine (1) threats to specific forest types and (2) how the distribution of avocado...

As demand for avocado climbs, avocado production in Michoacán - Mexico’s biggest avocado growing region - expands into new places. We use a spatial probit model to project the geographic distribution of likely future avocado expansion and analyze those results to determine (1) threats to specific forest types and (2) how the distribution of avocado...

Environmental perceptions are inherently based on an individual’s existing knowledge, experiences, and future expectations. Methods for measuring environmental perception, therefore, must capture a range of experiences while also being flexible enough to integrate these experiences into a coherent unit for analysis. Many research topics require cro...

Humans are intertwined with the environment, and the consequences are profound for biological diversity, and fundamental for planning conservation strategies and goals. The likely formal recognition of the Anthropocene Epoch allows for new approaches to measuring biodiversity, and for clarifying human roles in altering patterns and processes. Many...

Avocados have become a global commodity, and environmental and socioeconomic impacts in the regions where avocados are grown have increased in tandem with production. In this article, we synthesize the current state of knowledge about the impacts of avocado production in Michoacán, México, the global center of avocado production. Environmental impa...

Mountain wetlands are abundant in the high elevations of the tropical Andes. Wetlands occupy ~11% of the total park area and are mostly found in the large mountain valleys. Wetlands occur up to 5000 m asl, but most occur between 4,000–4,700 m asl. The highest elevation wetlands are typically dominated by cushion plants, while lower elevation wetlan...

Although species have always shifted their ranges, the rapid pace of current biophysical changes and the further complications imparted by human land use provide unprecedented challenges for biodiversity conservation. As a result, goals, methods, and strategies are being reconceptualized. For example, the terms conservation and wilderness protectio...

If he were living today, Alexander von Humboldt would be using current technology to evaluate change in the Andes. Inspired by von Humboldt's scientific legacy and the 2019 celebrations of his influence, we utilize a Moderate Resolution Imaging Spectroradiometer (MODIS)time-series vegetation index to ask questions of landscape change. Specifically,...

The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate contro...

Our knowledge about the structure and function of Andean forests at regional scales remains limited. Current initiatives to study forests over continental or global scales still have important geographical gaps, particularly in regions such as the tropical and subtropical Andes. In this study, we assessed patterns of structure and tree species dive...

As a result of climate warming and glacier recession, glacierized watersheds will experience a decrease in dry season discharge and an increase in wet season discharge, with negative consequences for water quality. The glacierized Rio Santa watershed in Peru provides the unique opportunity to study these concerns, because it drains the mountain ran...

Context Bees are the most important pollinators of crops worldwide. For most bees, patches of semi-natural habitat within or adjacent to crops can provide important nesting and food resources. Despite this, land cover change is rapidly reducing the abundance of semi-natural habitat within agroecological landscapes, with potentially negative consequ...

Neutral models are often used as null models, testing the relative importance of niche versus neutral processes in shaping diversity. Most versions, however, focus only on regional scale predictions and neglect local level contributions. Recently, a new formulation of spatial neutral theory was published showing an incompatibility between regional...

Endemism refers to the uniqueness of the biota of a particular place. It provides insights into the historical biogeography of regions, and helps evaluate the role of dispersal barriers in affecting the evolution of the biota. Oceanic islands such as the Galapágos have high endemism because of their distance from the mainland and because their biot...

The interactions between climate and land-use change are dictating the distribution of flora and fauna and reshuffling biotic community composition around the world. Tropical mountains are particularly sensitive because they often have a high human population density, a long history of agriculture, range-restricted species, and high-beta diversity...

It began as a disagreement about nouns, adjectives, and articles. In the fall of 2014, I had proposed a new class at the University of Texas at Austin meant to be entitled The Anthropocene. The appropriate paperwork was submitted, and came back rejected, with an explanation that courses could not have “The” at the start of the course title because...

In this study, we evaluate the effectiveness of indicators for rehabilitation practices in high mountain landscapes that were aimed at increasing grassland palatability and biomass accumulation. Focusing on the department of Huancavelica in Peru, the importance of rehabilitation practiced in this area involves the relationship of alpaca pastoralist...

In Fig. 2 of this Article, the positive part of the y axis scale should read 0, 0.02, 0.04 instead of 0, 0.04, 0.02. This has been corrected online.

Integral to the geographic discipline are cross-cultural analyses, many of which use languages outside of the researcher’s own. There are few analyses, however, that address issues of translation that are inherently geographic; namely, that language is understood as a manifestation of place and culture. This article argues that the results of envir...

Variability in environmental phenomena such as fire, flooding, and weather-related events can have significant impacts for social and environmental systems and their coupled interactions. Livelihoods systems reliant on the natural environment can be disrupted or eliminated, while associated governance regimes require negotiation to ensure equitable...

Global warming is forcing many species to shift their distributions upward, causing consequent changes in the compositions of species that occur at specific locations. This prediction remains largely untested for tropical trees. Here we show, using a database of nearly 200 Andean forest plot inventories spread across more than 33.5° latitude (from...

Research within geography and related disciplines has directed much attention to the coupled interactions between social and ecological systems. These studies have usefully analyzed the multifaceted, temporal, and scalar dimensions of human–environment interactions and how future environmental change will continue to challenge human resource needs....

Species distribution models (SDMs) are widely used in ecology and conservation. Presence-only SDMs such as MaxEnt frequently use natural history collections (NHCs) as occurrence data, given their huge numbers and accessibility. NHCs are often spatially biased which may generate inaccuracies in SDMs. Here, we test how the distribution of NHCs and Ma...

Belongs to paper Species Distribution Modelling: Contrasting presence-only models with plot abundance data by Gomes et al.

Comparing the results of modelling the area of occupancy with MaxEnt and with inverse distance weighting (IDW). Analysis results for the predicted area of occupancy as calculated by Maxent and IDW methods. The analyses were conducted for 170 of all 227 hyperdominant species that had MaxEnt’s predicted environmental suitability significantly differ...

Species distribution models (SDMs) are widely used in ecology and conservation. Presence-only SDMs such as MaxEnt frequently use natural history collections (NHCs) as occurrence data, given their huge numbers and accessibility. NHCs are often spatially biased which may generate inaccuracies in SDMs. Here, we test how the distribution of NHCs and Ma...

The objective of this research is to characterize the variability of trace metals in the Rio Santa watershed based on synoptic sampling applied at a large scale. To that end, we propose a combination of methods based on the collection of water, suspended sediments, and riverbed sediments at different points of the watershed within a very limited pe...

Accelerating glacier recession in tropical highlands and in the Peruvian Andes specifically is a manifestation of global climate change that is influencing the hydrologic cycle and impacting water resources across a range of socio-environmental systems. Despite predictions regarding the negative effects of long-term glacier decline on water availab...

The long-term survival of Andean forest landscapes (AFL) and of their capacity to contribute to sustainable development in a context of global change requires integrated adaptation and mitigation responses informed by a thorough understanding of the dynamic and complex interactions between their ecological and social components. This article propos...

The Okavango Delta in Botswana hosts abundant wildlife and a human population with diverse livelihoods. Representing a heterogeneous landscape nuanced by spatial and temporal variability, the region has recently seen an expansion of floodwaters with social impacts ranging from livelihood disruption to human displacement. This article reports on in-...

With many sophisticated methods available for estimating migration, ecologists face the difficult decision of choosing for their specific line of work. Here we test and compare several methods, performing sanity and robustness tests, applying to large-scale data and discussing the results and interpretation. Five methods were selected to compare fo...

Within the tropics, the species richness of tree communities is strongly and positively associated with precipitation. Previous research has suggested that this macroecological pattern is driven by the negative effect of water‐stress on the physiological processes of most tree species. This implies that the range limits of taxa are defined by their...

Past human influences on Amazonian forest The marks of prehistoric human societies on tropical forests can still be detected today. Levis et al. performed a basin-wide comparison of plant distributions, archaeological sites, and environmental data. Plants domesticated by pre-Columbian peoples are much more likely to be dominant in Amazonian forests...

The extent to which pre-Columbian societies altered Amazonian landscapes is hotly debated. We performed a basin-wide analysis of pre-Columbian impacts on Amazonian forests by overlaying known archaeological sites in Amazonia with the distributions and abundances of 85 woody species domesticated by pre-Columbian peoples. Domesticated species are fiv...

Endemism refers to the uniqueness of the biota of a particular place. It provides insights into the historical biogeography of regions, and helps evaluate the role of dispersal barriers in affecting the evolution of the biota. Oceanic islands such as the Galapagos have high endemism because of their distance from the mainland and because their biot...

Receding mountain glaciers affect the hydrology of downslope ecosystems with consequences for drinking water, agriculture, and hydropower production. Here we combined land cover derived from satellite imagery and other environmental data from the northern Peruvian Andes into a first differencing regression model to assess wetland hydrologic connect...

Lineages tend to retain ecological characteristics of their ancestors through time. However, for some traits, selection during evolutionary history may have also played a role in determining trait values. To address the relative importance of these processes requires large-scale quantification of traits and evolutionary relationships among species....

Comparison between published values of phylogenetic signal and values found in the present study

Examination of the dynamism of snowlines and treelines could provide insights into environmental change processes affecting land cover in the tropical Andes Mountains. Further, land cover at these ecotones represents a powerful lens through which to monitor and understand ecological processes across biophysical gradients while acknowledging their s...

Current and future impacts of climate change include increasing variability in a number of biophysical processes, such as temperature, precipitation, and flooding. The Intergovernmental Panel on Climate Change (IPCC) has suggested that Southern Africa is particularly vulnerable to the anticipated impacts from global climate change and that social a...

Within the tropics, the species richness of tree communities is strongly and positively associated with precipitation.Previous research has suggested that this macroecological pattern is driven by the negative effect of water-stress on thephysiological processes of most tree species. This process implies that the range limits of taxa are defined by...

List of plots encompassing the Floristic tree inventories for 577 plots compiled from RAINFOR database, with their respective coordinates in Latitude (Lat.) and Longitude (Long.) , area in hectare, number of individuals with diameter equal or superior to 10 cm, number of species, number of genera and data contributors. Plots with long term data and...

Phylogeny of 497 Amazonian tree and palm genera, with branches coloured according to wood density, potential tree size, maximum tree growth and mortality rates.

Comparison between published values of phylogenetic signal for traits of tropical forest trees measured by Blomberg's K statistic. Bar colour indicates the different studies [1-5]; bars in black are represented by traits calculated in the present study and shades of grey show values for published studies. Bars with negative values represent absence...

Phylogeny of 497 Amazonian tree and palm genera, with branches coloured according to wood density, potential tree size, maximum tree growth and mortality rates.

Description of the methods used to calculate intrinsic trait values to account for the effect of variation in environmental conditions among plots

Comparison between published values of phylogenetic signal for traits of tropical forest trees measured by Blomberg's K statistic. Bar colour indicates the different studies [1-5]; bars in black are represented by traits calculated in the present study and shades of grey show values for published studies. Bars with negative values represent absence...

Model comparison; Loadings for Phylogenetic Principal Componets Analysis (PPCA); Sensitivity analyses

Description of the methods used to calculate intrinsic trait values to account for the effect of variation in environmental conditions among plots

List of plots encompassing the Floristic tree inventories for 577 plots compiled from RAINFOR database, with their respective coordinates in Latitude (Lat.) and Longitude (Long.) , area in hectare, number of individuals with diameter equal or superior to 10 cm, number of species, number of genera and data contributors. Plots with long term data and...

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Estimates of extinction risk for Amazonian plant and animal species are rare, and not often incorporated into land-use policy and conservation planning. Here we overlay spatial distribution models with historical and projected deforestation to show that at least 40% and up to 64% of all Amazonian tree species are likely to qualify as globally threa...

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened...

The past and present impacts of humans on the biosphere have altered many ecological and evolutionary processes. One of the most dramatic set of examples comes from domestication, which has transformed species, landscapes, and socioeconomic systems over the last 30 millennia. Recent research driven by advances in molecular biology and information s...

This edited volume, showcasing cutting-edge research, addresses two primary questions - what are the main drivers of change in high-mountains and what are the risks implied by these changes? From a physical perspective, it examines the complex interplay between climate and the high-mountain cryosphere, with further chapters covering tectonics, volc...