**1. Introduction**

Abiotic and biotic factors can act synergistically to influence growth, longevity, and distribution of plants [1]. Abiotic factors include disturbance regimes, light intensity, availability of water, and microelemental concentrations, among other factors [1, 2]. Biotic factors include competition, predation, and propagule pressure, among other factors [2, 3]. When plants respond to abiotic and biotic factors, the resulting growth, longevity, and distribution can be used to understand the dominant factor(s) affecting success in a habitat. This understanding arises when the abiotic and biotic factors are known, and then analyses can be completed to identify the factor(s) responsible for observed growth, longevity, and distribution. In these settings, it is often feasible to identify one or more plant species as bioindicators, to represent patterns [1–5]. This approach uses existing knowledge on ecological,

physiological, and ontological requirements of bioindicator species. Hence, the status of bioindicator species in a habitat can be used as a surrogate to identify the dominant abiotic and biotic factors shaping plants within an area of interest [5, 6].

Studies of plants and plant communities exposed to brine from oil and gas wells, referred to herein as hydrocarbon extraction areas (HEAs), demonstrated the short- and long-term consequences of this type of episodic and/or persistent disturbance [7–12]. Historically, brine was allowed to drain away from HEAs and was then observed to kill all exposed plants [7, 8]. Best practices now involve the capture of brine for safe disposal [7]. Brine from HEAs varies from locale to locale but always contains high concentrations of elements, like Cl >50,000 mg/L, Na >25,000 mg/L, Ca > 10,000 mg/L, Mg >1000 mg/L, SO4 −2 > 500 mg/L, and Fe > 200 mg/L with total dissolved solids (TDS) > 100,000 mg/L [7, 13, 14]. When brine drains to adjacent plant communities, most species will show a short-term response involving the leaves turning white, indicating the loss of chlorophyll, referred to as chlorosis, with leaf drop soon thereafter [7, 15, 16]. The process of chlorosis is attributed to the loss of ionic balance in the roots and leaves of the plant, attributable to the high concentrations of elements such as Cl and Na in the brine [12, 15].

A detailed study of the response of plants to long-term exposure of brine was completed by government scientists in former oak (*Quercus* sp.)-dominated forest of Oklahoma, USA [7]. This Oklahoma study documented how herbaceous and woody vegetations were completely absent in areas that received brine runoff during the past, while trees downslope were short and demonstrated dead branches. In contrast, herbaceous and woody vegetation upslope and adjacent to the brine-exposed areas showed no evidence of stress [1]. The authors attributed the loss of ground vegetation and the short height and dead branches of the trees to long-term exposure to brine from HEAs. Another study that documented the response of plants to brine exposure was completed in the Allegheny State Forest in Pennsylvania, USA [15, 16]. This forest patch was dominated by trees such as eastern hemlock (*Tsuga canadensis* L. Carrière), red maple (*Acer rubrum* L.), American beech (*Fagus grandifolia* Ehrh.), northern red oak (*Quercus rubra* L.), and yellow birch (*Betula alleghaniensis* Britton). This forest was exposed to brine from a leaking impoundment over a period of 3 years. The path followed by the brine resulted in the death of all ground vegetation during the first season and all trees within 2 years. Walters and Auchmoody ([15], p. 124) stated: "The swiftness and completeness of the kill attests to the extremely toxic nature of the spilled brine. Ground cover was eliminated immediately, and trees showed visual symptoms of stress during the first growing season…." The last plants to die were the old growth (>300 years old) eastern hemlock and American beech in the drainage area. The extended survival of these large and old trees was attributed to the deep roots providing some tolerance to the brine, but they still died. It was also reported that within 2 years, plants returned to the brine-disturbed forest areas, with typical pioneer species, including ferns, as first to appear, followed by previously evident woody species [16]. Studies that document the response of plants to brine exposure during short- and long-term periods represent an opportunity for learning about species and community response patterns to this type of disturbance [17, 18]. Schindler [18] suggested such severe types of disturbance are useful for learning about responses of species and communities to a disturbance but do not necessarily represent the key variables to help elucidate exact response patterns. Schindler [18] also noted that disturbance regimes can provide a basis to resolve cause-effect relationships and are instructive if the response patterns are indeed outside of the typical normal range. Schindler [18] also suggested that understanding the exact responses of species and communities to disturbance can lead to the development

**105**

**Figure 1.**

*and six forest sites are within the brown oval.*

*Eastern Poison Ivy (*Toxicodendron radicans *L.): A Bioindicator of Natural and Anthropogenic…*

of a predictive framework of responses for low-level disturbance. Using this basis, additional studies of plants associated with HEAs and brine are justified, to resolve growth, longevity, and distribution of plants in these areas, as a basis to refine

*View of Manitoulin Island, Lake Huron, Ontario. The approximate boundaries (less adjacent lands) of WUT are noted within the yellow oval, along the entire eastern end of the island. The general area of the five field* 

This chapter reports how the distribution of eastern poison ivy (EPI; *Toxicodendron radicans* L.) has been used as a diagnostic indicator to locate lost HEAs that include oil and gas wells in fields and forests. These lost HEAs exist on Wiikwemkoong Unceded Territory (WUT) #26, an area that extends along the entire east shoreline of Manitoulin Island, Lake Huron, Ontario, Canada (**Figure 1**). Portions of Manitoulin Island and WUT are located over the Collingwood Oil Shale Formation (Ordovician origin) containing oil and gas deposits within the porous limestone of the Trenton Formation [19, 20]. Since 2014, members of WUT have been working with Premier Environmental Services Inc. (Premier), to rediscover lost HEAs using an approach that integrates oral traditional knowledge (TK) with plant ecology and chemistry-based analyses [21]. This discovery process has been refined since 2014, with the integration of TK and science to help understand the distribution of EPI along with the status of the plant communities in proximity to candidate HEAs. Direct experience at WUT allowed for the refinement of this understanding of how EPI represents a bioindicator species to represent the responses of other herbaceous and woody plant species in these habitats at 50+ HEAs. Documentation of the response of EPI and plant communities associated with HEAs was achieved with detailed studies of five field and six forest sites, including a groundwater seep in a field and natural hydrocarbon seep in a forest. This representation of the responses of plants to local habitat features provides the basis for learning about the key environmental factors shaping the growth, longevity, and distribution of plants in areas with

*DOI: http://dx.doi.org/10.5772/intechopen.88150*

future rehabilitation activities.

HEAs and natural seeps.

*Eastern Poison Ivy (*Toxicodendron radicans *L.): A Bioindicator of Natural and Anthropogenic… DOI: http://dx.doi.org/10.5772/intechopen.88150*

of a predictive framework of responses for low-level disturbance. Using this basis, additional studies of plants associated with HEAs and brine are justified, to resolve growth, longevity, and distribution of plants in these areas, as a basis to refine future rehabilitation activities.

This chapter reports how the distribution of eastern poison ivy (EPI; *Toxicodendron radicans* L.) has been used as a diagnostic indicator to locate lost HEAs that include oil and gas wells in fields and forests. These lost HEAs exist on Wiikwemkoong Unceded Territory (WUT) #26, an area that extends along the entire east shoreline of Manitoulin Island, Lake Huron, Ontario, Canada (**Figure 1**). Portions of Manitoulin Island and WUT are located over the Collingwood Oil Shale Formation (Ordovician origin) containing oil and gas deposits within the porous limestone of the Trenton Formation [19, 20]. Since 2014, members of WUT have been working with Premier Environmental Services Inc. (Premier), to rediscover lost HEAs using an approach that integrates oral traditional knowledge (TK) with plant ecology and chemistry-based analyses [21]. This discovery process has been refined since 2014, with the integration of TK and science to help understand the distribution of EPI along with the status of the plant communities in proximity to candidate HEAs. Direct experience at WUT allowed for the refinement of this understanding of how EPI represents a bioindicator species to represent the responses of other herbaceous and woody plant species in these habitats at 50+ HEAs. Documentation of the response of EPI and plant communities associated with HEAs was achieved with detailed studies of five field and six forest sites, including a groundwater seep in a field and natural hydrocarbon seep in a forest. This representation of the responses of plants to local habitat features provides the basis for learning about the key environmental factors shaping the growth, longevity, and distribution of plants in areas with HEAs and natural seeps.

### **Figure 1.**

*Plant Communities and Their Environment*

in the brine [12, 15].

physiological, and ontological requirements of bioindicator species. Hence, the status of bioindicator species in a habitat can be used as a surrogate to identify the dominant abiotic and biotic factors shaping plants within an area of interest [5, 6]. Studies of plants and plant communities exposed to brine from oil and gas wells, referred to herein as hydrocarbon extraction areas (HEAs), demonstrated the short- and long-term consequences of this type of episodic and/or persistent disturbance [7–12]. Historically, brine was allowed to drain away from HEAs and was then observed to kill all exposed plants [7, 8]. Best practices now involve the capture of brine for safe disposal [7]. Brine from HEAs varies from locale to locale but always contains high concentrations of elements, like Cl >50,000 mg/L,

Fe > 200 mg/L with total dissolved solids (TDS) > 100,000 mg/L [7, 13, 14]. When brine drains to adjacent plant communities, most species will show a short-term response involving the leaves turning white, indicating the loss of chlorophyll, referred to as chlorosis, with leaf drop soon thereafter [7, 15, 16]. The process of chlorosis is attributed to the loss of ionic balance in the roots and leaves of the plant, attributable to the high concentrations of elements such as Cl and Na

A detailed study of the response of plants to long-term exposure of brine was completed by government scientists in former oak (*Quercus* sp.)-dominated forest of Oklahoma, USA [7]. This Oklahoma study documented how herbaceous and woody vegetations were completely absent in areas that received brine runoff during the past, while trees downslope were short and demonstrated dead branches. In contrast, herbaceous and woody vegetation upslope and adjacent to the brine-exposed areas showed no evidence of stress [1]. The authors attributed the loss of ground vegetation and the short height and dead branches of the trees to long-term exposure to brine from HEAs. Another study that documented the response of plants to brine exposure was completed in the Allegheny State Forest in Pennsylvania, USA [15, 16]. This forest patch was dominated by trees such as eastern hemlock (*Tsuga canadensis* L. Carrière), red maple (*Acer rubrum* L.), American beech (*Fagus grandifolia* Ehrh.), northern red oak (*Quercus rubra* L.), and yellow birch (*Betula alleghaniensis* Britton). This forest was exposed to brine from a leaking impoundment over a period of 3 years. The path followed by the brine resulted in the death of all ground vegetation during the first season and all trees within 2 years. Walters and Auchmoody ([15], p. 124) stated: "The swiftness and completeness of the kill attests to the extremely toxic nature of the spilled brine. Ground cover was eliminated immediately, and trees showed visual symptoms of stress during the first growing season…." The last plants to die were the old growth (>300 years old) eastern hemlock and American beech in the drainage area. The extended survival of these large and old trees was attributed to the deep roots providing some tolerance to the brine, but they still died. It was also reported that within 2 years, plants returned to the brine-disturbed forest areas, with typical pioneer species, including ferns, as first to appear, followed by previously evident woody species [16]. Studies that document the response of plants to brine exposure during short- and long-term periods represent an opportunity for learning about species and community response patterns to this type of disturbance [17, 18]. Schindler [18] suggested such severe types of disturbance are useful for learning about responses of species and communities to a disturbance but do not necessarily represent the key variables to help elucidate exact response patterns. Schindler [18] also noted that disturbance regimes can provide a basis to resolve cause-effect relationships and are instructive if the response patterns are indeed outside of the typical normal range. Schindler [18] also suggested that understanding the exact responses of species and communities to disturbance can lead to the development

−2 > 500 mg/L, and

Na >25,000 mg/L, Ca > 10,000 mg/L, Mg >1000 mg/L, SO4

**104**

*View of Manitoulin Island, Lake Huron, Ontario. The approximate boundaries (less adjacent lands) of WUT are noted within the yellow oval, along the entire eastern end of the island. The general area of the five field and six forest sites are within the brown oval.*
