Jonathan Phillips

University of Kentucky | UKY · Department of Geography

Coastal backwater effects on low-gradient coastal plain rivers extend well upstream of the head of the estuary and propagate upstream as sea-level rises. Hydrological, geomorphological, and ecological indicators can serve as sentinels of the upriver encroachment. Analyzing the along-river spatial distribution of these indicators as a space-for-time...

Based on international cooperation, we collect data on uprooted trees and prepare a global model. We currently have more than 2700 cases from various forest types in database. You can visit the Database, see its structure and site locations.

Research on biogeomorphic and soil evolutionary role of trees in temperate and tropical forests

Multiple pathways and outcomes are common in evolutionary sequences for biological and other environmental systems due to nonlinear complexity, historical contingency, and disturbances. From any starting point, multiple evolutionary pathways are possible. From an endpoint or ob-served state, multiple possibilities exist for the sequence of events t...

Ghost cypress”—standing trees killed by increased salinity—indicate sea-level rise (SLR) effects along lower reaches of many coastal plain rivers. Mature cypress can survive indefinitely in permanently flooded sites, but experience mortality at salinities as low as 2 to 3 ppt. Thus, ghost trees in permanently inundated sites can indicate mortality...

Leaf-cutter ants belonging to the genus Atta are important ecosystem engineers and conspicuous bioturbators in Neotropical regions acting as superorganisms. The Atta ants excavate impressive and long-lived nests with complex subterranean systems that provide shelter from predation and climatic extremes and allow reproduction and fungus-growing. Des...

We suggest that biogeomorphology should challenge the traditional dichotomy between living and non‐living components of Earth surface systems. To achieve this, biogeomorphologists should gain a better understanding of eco‐evolutionary models and empirical findings developing at the interface between ecology and evolutionary biology. Eco‐evolutionar...

This paper was written but never published about 10 years ago. The premise is that: (1) tipping points and regime shifts are of major concern with respect to impacts of global climate change. (2) Tipping points and regime shifts are types of thresholds. (3) Thresholds have played a key role in geomorphology for half a century or so. (4) Lessons lea...

In Earth surface systems (ESS), everything is connected to everything else, an aphorism often called the First Law of Ecology and of geography. Such linkages are not always direct and unmediated, but many ESS, represented as networks of interacting components, attain or approach full, direct connectivity among components. The question is how and wh...

The question of whether the concept of adaptation can be applied to Earth surface systems (independently of biological adaptation) is addressed by examining hydrolog- ical flow systems. Hydrological systems are represented in terms of a partitioning of water inputs among various flux and storage components and outflows or outputs of the system. Par...

Determining effects of climate change on landscapes involves numerous uncertainties. This paper presents and illustrates a protocol for climate attribution of landscape responses. The major steps are ascertaining potential climate-related responses, establishing plausibility for a climatic influence, identifying alternative or additional causes, te...

Concentrated or preferential flow patterns occur at all scales in hydrologic systems. They shape, and are shaped by, geomorphic and pedologic patterns and structures. Preferential flow patterns in surface channel networks and dual-porosity subsurface flow systems are a way of achieiving maximum efficiency, as predicted by dissipative systems, const...

Tree mortality can fundamentally affect soils, which in turn shape forest regeneration and dynamics. Here, we quantify the dynamics of soil volumes associated with tree mortality, parsing effects by mode of tree death (broken vs uprooted) and species. The concept of ecosystem biogeomorphic succession was also tested. We used repeated tree censuses...

The fluvial‐estuarine transition zone (FETZ) of the Neuse River, North Carolina features a river corridor that conveys flow in a complex of active, backflooded, and high‐flow channels, floodplain depressions, and wetlands. Hydrological connectivity among these occurs at median discharges and stages, with some connectivity at even lower stages. Wate...

Geography and geosciences deal with phenomena that span spatial scales from the molecular to the planetary, and temporal scales from instantaneous to billions of years. A strong reductionist tradition in geosciences and spatial sciences tempts us to seek to apply similar representations and process-based explanations across these vast-scale ranges,...

In September 2018 Hurricane Florence had severe impacts on the lower Neuse River and Neuse estuary, North Carolina, despite the fact that it was a minor storm in terms of traditional indicators of storm intensity. The storm was consistent with recent trends and predictions of tropical cyclone activity driven by Anthropocene climate warming. However...

Landscape Evolution asks us to think holistically, to look for the interactions between the Earth’s component surface systems, to consider how universal laws and historical and geographical contingency work together, and to ponder the implications of nonlinear dynamics in landscapes, ecosystems, and soils. Development, evolution, landforms, topogra...

Biogeomorphological and ecological succession following a disturbance or the exposure of new ground often proceeds in stages, from domination by abiotic, geophysical factors through stages characterized by increasing effects of biota, biotic-abiotic feedbacks, and eventual domination by ecological processes. However, some studies in forest settings...

History matters. Global (independent of place and time) principles are necessary to explain landscape evolution, as are place factors (geographical and environmental context). But, by themselves, they are not sufficient. To explain landscape evolution—which by definition has important temporal dimensions—history must also be incorporated. Landscape...

The Perfect Landscape is a broad, but formally expressed, conceptual model incorporating the law-place-history explanatory triad, explicitly dealing with contingency, and recognizing the interplay of individuality and idiosyncrasies in Earth surface system with shared characteristics and regularities. It holds that individual landscapes reflect a c...

An approach to landscape and Earth surface system evolution is outlined based on the inseparability of landform, soil, and ecosystem development, versus the traditional semi-independent treatment of geomorphic, ecological, pedological, and hydrological phenomena. Key themes are the coevolution of biotic and abiotic components of the environment; se...

Landscapes are influenced by processes operating at scales from molecules to planets, and over time spans ranging from instantaneous to billions of years. Thus scale contingency is an innate, unavoidable aspect of landscape evolution, and is common in landscapes. The laws, place, and history factors relevant to landscape evolution may vary with spa...

Thresholds are ubiquitous in Earth surface systems and fundamental to landscape evolution. They occur at the level of process mechanics, and at the broader level of landscape system states, and may be fuzzy or crisp in their occurrence and/or the ability to measure or define them. Five main types of thresholds occur: force vs. resistance, storage c...

Landscape evolution often occurs over long-time scales that do not allow for direct observation and measurement. This chapter reviews approaches for observing, inferring, and reconstructing evolutionary trajectories. These include direct observation and monitoring (e.g., observatories), simulation models, and historical reconstruction. The latter e...

This chapter focuses on the (not necessarily final) destination of landscape evolution—the attractors that landscapes may move toward and the goal functions that govern these trajectories. Single-outcome concepts posit that landscape systems move toward a single self-perpetuating state. These include notions of progression toward climax or mature f...

Ecosystems and landscapes are supraorganisms (not superorganisms), defined as highly interconnected biotic-abiotic systems which meet two criteria: (1) Significant changes to any component result in changes to the system as a whole, and responses and adaptations occur at the ecosystem level (in addition to responses of ecosystem constituents) and i...

Darwinian natural selection acting on individuals is one of only several types of selection influencing landscape evolution. Ecological filtering and abiotic selection (including the least action principle and preferential flows) apply. The overarching principle is one of efficiency selection, whereby more efficient, stable, and durable forms, stru...

Earth faces serious contemporary and future environmental change. The principles of landscape evolution outlined here provide valuable lessons for understanding, interpreting, managing, and responding to those changes, which are reviewed here. The theory outlined in this book can be summarized as TREE: Transformative, Reciprocal, Emergent Evolution...

https://authors.elsevier.com/a/1blC23HcE1cwu3 Outbreaks of bark beetles, for example Ips typographus L. in Eurasia or Dendroctonus ponderosae Hopkins in North America, have serious impacts on forest resources, biodiversity, and ecological dynamics, with economical and social ramifications. Moreover, many models predict increasing frequency and seve...

Evolution of weathering profiles (WP) is critical for landscape evolution, soil formation, biogeochemical cycles, and critical zone hydrology and ecology. Weathering profiles often include soil or solum (O, A, E, and B horizons), non-soil regolith (including soil C horizons, saprolite), and weathered rock. Development of these is a function of weat...

Climate change impacts are a serious threat to food provisioning, security and the economy. Thus, assessing agricultural suitability and yield reduction under climate change is crucial for sustainable agricultural production. In this study, we used two sub-models of the agro-ecological decision support system MicroLEIS (Terraza and Cervatana) to ev...

We measured fine sediment accumulations (FSA) adjacent to eroding off-highway vehicle trails in Ouachita National Forest, Arkansas. Measured trailside FSA was 643 m3. Extrapolated to the entire trail network, this amounts to 216 t ha⁻¹ of trail surface, with a residence time of <1 yr. Natural topographic features are the main storage sites, account...

Biogeomorphic keystone species profoundly impact landscapes, such that their introduction or removal would cause fundamental changes in geomorphic systems. This paper explores the concept of biogeomorphic keystone species by examining the general vs. species‐specific biogeomorphic impacts (BGIs) of trees on a limestone bedrock‐controlled stream, Sh...

Case studies of ecosystem responses to changing climates are necessary in understanding and adapting to these changes. However, more general conceptual frameworks are also needed to contextualize and synthesize case studies, and to provide guidelines for assessment and prediction. This study analyzes a network model of ecological and soil state fac...

In biological evolution, creativity occurs in the appearance of new entities by evolutionary dynamics. This is linked to mutations and genetic drift, which cannot occur in geophysical phenomena. Biota can exhibit evolutionary creativity that influences landforms, but how does creativity (defined here as the capacity for emergence of new entities th...

Factors influencing sediment availability are assessed and erosion rates are quantified for an off‐highway vehicle (OHV) trail system in the Ouachita Mountains of Arkansas. As of May 2012, the Wolf Pen Gap trail system included 77.0 km of "trails" which consist of county roads; open and closed Forest Service roads; and open and closed OHV trails. F...

Understanding evolution of soils and landforms (and other Earth surface systems) has itself evolved from concepts of single-path, single-outcome development to those that recognize multiple possible developmental trajectories and different maturely developed states. Soil geomorphology and pedology should now move beyond showing that multiple trajec...

A distinct boundary between unweathered and weathered rock that moves downward as weathering proceeds—the weathering front—is explicitly or implicitly part of landscape evolution concepts of etchplanation, triple planation, dynamic denudation, and weathering- and supply-limited landscapes. Weathering fronts also figure prominently in many models of...

Upper Board Camp Creek (BCC) in western Arkansas drains the Wolf Pen Gap (WPG) Trail Complex, a designated Off-Highway Vehicle (OHV) area in use since the 1990s. The mixed bedrock-alluvial channel is quite active, with extensive bars and eroding banks present within the higher-order, main-valley channels. This study was conducted to determine the r...

Relative sea-level rise (SLR) raises geomorphic base levels, displaces salt water and tidal or backwater effects inland, and changes the hydrology of aquatic and upland environments. On an all-other-things-being equal basis, we can predict some transitions associated with SLR. However, in real coastal landscapes, all other things are not equal. Fac...

Nine axioms for interpreting landscapes from a geoscience perspective are presented, and illustrated via a case study. The axioms are the self-evident portions of several key theoretical frameworks: multiple causality; the law–place–history triad; individualism; evolution space; selection principles; and place as historically contingent process. Re...

Tree roots have biogeomorphic engineering effects on epikarst weathering and soil deepening. This is investigated using a system model describing the interactions among biogeomorphic effects of roots, weathering, and soil-epikarst development. The model shows that the system is dynamically unstable when roots are limited by subsurface accommodation...

Anticipating geomorphic tipping points requires that we learn from the past. Major geomorphic changes in coastal plain rivers of Texas resulting in river metamorphosis or regime shifts were identified and the major driving factors determined. Eleven such transformations--possible tipping points--were identified from contemporary observations, histo...

The role of biomechanical effects of trees (BETs) in ecosystem and landscape dynamics is poorly understood. In this study, we aim to (i) describe a widely applicable methodology for quantifying the main BET in soil, and (ii) analyze the actual frequencies, areas and soil volumes associated with these effects in a mountain temperate old-growth fores...

Geomorphic and hydraulic units in river channels are closely linked to geodiversity and habitats, and thus to biodi- versity. In a ~ 200 km reach of the lower Sabine River, in the northern Gulf of Mexico Coastal Plain, 72 different hydraulic units (HU) were identified in six geomorphic zones or river styles. Richness–area relationships indicate a l...

Lateral and vertical erosion at meander bends in the Kentucky River gorge area has created a series of strath terraces on the interior of incised meander bends. These represent a chronosequence of fluviokarst landscape evolution from the youngest valley side transition zone near the valley bottom to the oldest upland surface. This five-part chronos...

Tree breakage and uprooting are two possible scenarios of tree death that have differing effects on hillslope processes. In this study we aimed to (i) reveal the long-term structure of the biomechanical effects of trees (BETs) in relation to their radial growth and tree death types in four old-growth temperate forests in four different elevation se...

This document is a collection of Jonathan Phillips’ Geoscience Blog posts from its inception (29 May 2014) through 2 July 2017. The major sections include (1) How it's Done; (2) Earth Surface System Theory 1: Equilibrium & Otherwise; (3)Earth Surface System Theory 2: Nonlinear Dynamics, Complexity, Self-Organization, Power Laws; (4) Earth Surface S...

Flow diversions and landform transitions between channelized surface (fluvial) and concentrated subsurface (karst conduit) flows may be common in fluviokarst landscapes. Identifying landforms associated with fluvialto- karst or karst-To-fluvial transitions shows this to be the case at three study sites in the Inner Bluegrass karst region of Kentuck...

State-and-transition models (STM) are used to describe, model, interpret, and predict when landscapes will undergo a qualitative state change. Although rangeland ecologists pioneered STMs, geomorphological STM-type models were developed prior to and independently of ecological STMs. This study categorized 47 geomorphological STMs according to wheth...

This paper reviews recent developments in studies of soil complexity, focusing on the variability of soil types within soil landscapes. Changes in soil complexity are directly related to divergent and convergent pedogenesis and to dynamical stability and chaos. Accordingly, strong links exist between nonlinear dynamical systems theory and studies o...

Metanarratives are critiqued and even rejected by many geographers and geoscientists. Yet, despite the inescapable role of geographical and historical contingency in physical geography, metanarratives are helpful, perhaps even necessary, in part because equifinality is common in Earth surface systems (ESS). Similarity of forms and patterns implies...

The role of biomechanical effects of trees (BET) in ecosystem and landscape dynamics is poorly understood. In this study, we aim to (i) describe a widely applicable methodology for quantifying the main BET in soil, and (ii) analyze the actual frequencies, areas and soil volumes associated with these effects in a mountain forest. The research took p...

Biomechanical effects of trees in forest soils represent a potentially significant factor in hillslope processes, pedocomplexity and forest dynamics. However, these processes have been only rarely studied so far. Within this study we aim (i) to elaborate a detailed and widely applicable methodology of quantification of the main biomechanical effect...

G.K. Gilbert's (1917) classic monograph, Hydraulic-Mining Débris in the Sierra Nevada, is described and put into the context of modern geomorphic knowledge. While the emphasis is on large-scale applied fluvial geomorphology, which is represented very well, other key elements—e.g., coastal geomorphology—are briefly covered. A brief synopsis outlines...

Agricultural land suitability evaluation is a good way to distinguish soil suitability in order to improve the soils by addressing major limitations. This study investigated the influence of soil factors variability on the suitability of 12 Mediterranean crops in southern Spain. To represent the variability in elevation, lithology, and soil, two la...

Geomorphic system resilience is often perceived as an intrinsic property of system structure and interactions but is also related to idiosyncratic place and history factors. The importance of geographical and historical circumstances makes it difficult to generate categorical statements about geomorphic resilience. However, network-based analyses o...

The state of an Earth surface system (ESS) is determined by three sets of factors: Laws, place, and history. Laws (L = L1, L2, . . . , Ln) are the n general principles applicable to any such system at any time. Place factors (P = P1, P2, . . . , Pm) are the m relevant characteristics of the local or regional environment. History factors (H = H1 , H...

Razula forest preserve in the Carpathian Mountains of the Czech Republic is an unmanaged forest that has not been logged or otherwise anthropically disturbed for at least 83 years, preceded by only infrequent selective logging. We examined this 25 ha area to determine the dominant geomorphological processes on the hillslope. Tree uprooting displace...

Soil diversity and complexity is influenced by a variety of factors, and much recent research has been focused on interpreting or modeling complexity based on soil-topography relationships, and effects of biogeomorphic processes. We aimed to (i) describe local soil diversity in one of the oldest forest reserves in Europe, (ii) employ existing graph...

Evolution of Earth surface systems (ESS) comprises sequential transitions between system states. Treating these as directed graphs, algebraic graph theory was used to quantify complexity of archetypal structures, and empirical examples of forest succession and alluvial river channel change. Spectral radius measures structural complexity and is high...

The most important geomorphic responses to storms are qualitative changes in system state. Minor storms produce no state change or very rapid recovery to pre‐storm state, and extinction events wipe out the system. In other cases disturbance results in a state change, which may be transitional (change to a previously existing state), state space exp...

The role of trees and forests as a critical component of the biosphere and critical zone, and of the Earth system more generally, is widely appreciated. Less known and acknowledged are the geomorphological functions of tree roots, though their importance has been widely referred to in soil studies, paleopedology and palaeobotany. Tree roots and the...

Scale linkage problems in geosciences are often associated with a hierarchy of components. Both dynamical systems perspectives and intuition suggest that processes or relationships operating at fundamentally different scales are independent with respect to influences on system dynamics. But how far apart is “fundamentally different”—that is, what i...

While karst is not biogenic in the same sense as, say, coral reefs or peat bogs, and carbonate dissolution can occur abiotically, formation of karst landscapes would not occur in the absence of the biosphere. Seven levels of biogeomorphic biotic-abiotic interactions are identified, from indirect impacts to landforms as extended phenotypes. Karst is...

Biotic influences on geomorphology (and vice-versa) are ubiquitous. This paper explores whether landforms may be extended (composite) phenotypes of biota, based on four criteria: process–form relationships between biota and landforms; evolutionary synchrony; selective pressure via ecosystem engineering and niche construction; and positive feedback...

I am at the age & stage of career where I have to choose my battles, and this is one I don't really have time for. This paper was submitted to Catena in February, 2015, and received two reviews recommending minor revision. A revised version was submitted June 1, 2015, but a third reviewer was strongly critical and Catena’s editor decided to reject...

Chronosequences are a fundamental tool for studying and representing change in Earth surface systems. Increasingly, chronosequences are understood to be much more complex than a simple monotonic progression from a starting point to a stable end-state. The concept of path stability is introduced here as a measure of chronosequence robustness; i.e.,...

We studied tree uprooting associated with an EF2 tornado that touched down in portions of the Ouachita Mountains in western Arkansas in 2009. In the severe blowdown areas all trees in the mixed shortleaf pine–hardwood forest were uprooted or broken, with no relationship between tree species or size and whether uprooting or breakage occurred. There...

River science and management often require a design or reference discharge. The common (and sometimes unavoidable) use of such discharges may, however, obscure the fact that the magnitude and frequency of critical flows can differ due to various hydrological, geomorphological, and ecological criteria. Threshold stages and discharges were identified...

The archetypal badass is individualistic, non-conformist, and able to produce disproportionate results. The badass concept is applied here to geomorphology. The individualistic concept of landscape evolution (ICLE) is introduced, based on three propositions: excess evolution space, capacity of all landforms to change, and variable selection pressur...

Applications of graph theory have proliferated across the academic spectrum in recent years. Whereas geosciences and landscape ecology have made rich use of graph theory, its use seems limited in physical geography, and particularly in geomorphology. Common applications of graph theory — analyses of connectivity, path or transport efficiencies, sub...

Invasive species, often recognized as ecosystem engineers, can dramatically alter geomorphic processes and landforms. Our review shows that the bio-geomorphic impacts of invasive species are common, but variable in magni-tude or severity, ranging from simple acceleration or deceleration of preex-isting geomorphic processes to landscape metamorphosi...

Active and semi-active anastomosing Holocene channels upstream of the delta in the lower valley of the meandering Neches River in southeast Texas represent several morphologically distinct and hydrologically independent channel systems. These appear to have a common origin as multi-thread crevasse channels strongly influenced by antecedent morpholo...

Abstract: Tipping points in global environmental change are characterized by rapid transitions or state changes. Considerable uncertainty and debate exists about the nature of these abrupt transitions. Tipping points are thresholds, and thresholds have been thoroughly integrated into theory and conceptual models in geomorphology for decades. Experi...

The evolution of fluviokarst landscapes is little understood, but is intimately related to the partitioning of water flows among surface, subsurface, concentrated and diffuse pathways. This partitioning is examined using principles of gradient selection and threshold modulation, to determine circumstances under which transfers or transformations oc...

Landform and landscape evolution may be convergent, whereby initial differences and irregularities are (on average) reduced and smoothed, or divergent, with increasing variation and irregularity. Convergent and divergent evolution are directly related to dynamical (in)stability. Unstable interactions among geomorphic system components tend to domin...

The genesis of soils has been seen mostly as an autochthonistic process, that is, formation in situ. However, soil geomorphologists have recognized addition and loss of materials, for example, through eolian and colluvial processes, as a major contribution to allochthonistic soil formation.The most important characteristic of these soils is the lit...

The flow-channel fitness model is a conceptual and practical model for predicting the qualitative response of alluvial channels to modifications of flow regimes. 'Fitness' refers to the size of channels compared with the flows they convey, with the terminology derived from traditional geomorphic concepts of overfit and underfit streams. The qualita...

This study explores the origin of 15 small coastal watersheds (SCWs) conned entirely to the lower Coastal Plain, which lie between the watersheds of the major rivers owing across the Texas Coastal Plain. The relationship between SCWs and larger rivers was examined to determine whether the SCWs developed indepen-dently of the larger rivers, or becam...

The recent literature suggests that the network structure of ecological states within a system can determine whether the system’s response to environmental changes is reinforced by positive feedback mechanisms (amplification); rapidly propagated throughout the entire network of states (synchroniza- tion); or structurally constrained. The purpose of...

Soil types or map units are considered to be taxonomically adjacent if they differ in only one criterion, defined by an arbitrary threshold value. By treating soil types as nodes of a graph and taxonomic adjacency as the graph edges connecting nodes, algebraic graph theory can be used to produce a measurement of the uncertainty in a soil map associ...