THE OHIO ISLAND: Species and Trends in Faunal Biodiversity in the Ohio Valley

This topic submitted by on 12/10/02.

THE OHIO ISLAND:Species and Trends in Faunal Biodiversity in the Ohio Valley

Researchers:
Heather AllenÊ
Bradley H. Martin
Greg Dutton

*Special gratitude is extended to Carolyn Caldwell of the Ohio Fish And Wildlife Division and the Ohio Dept of Natural Resources for images.

EXECUTIVE SUMMARY

Over the course of the last 28 years the Ohio Department of Natural Resources' Fish and Wildlife Division has maintained a list of species that are considered endangered, threatened, or of special interest in the state. Be it that biodiversity is the key component to a healthy ecosystem, any loss of such biodiversity can result in significant and lasting damage. This report examines the historical trends as the state of Ohio contends with loss of biodiversity and attempts to ascribe causal factors in the changes that have occurred.

INTRODUCTION

The anthropogenic effects of urbanization and agricultural intrusion into the Ohio Valley have devastated many of the areas where native faunal species inhabit. The loss of habitats has contributed to the extirpation and endangerment of some faunal organisms and to the extinction of others. We hypothesize that the rate at which these events are occurring has slowed since the inception of the modern environmental movement. However, some species are still in danger. These species may be listed by the Ohio department of Fish and Wildlife as special interest or threatened but not endangered species. Until now, no one has ever completed a comprehensive study compiling, sorting, and analyzing as to the effects of different generalized species endangerment extirpation, threatening, etc. We have forged ahead in this mode of conservation study to show how loss of species and their habitat may effect other species decline or recovery.

RELEVANCE

In 1949 the Ohio Division of Wildlife was founded to monitor and protect species threatened through human encroachment. The Ohio Department of Natural Resources compiled the state's first list of endangered and threatened species in 1974 to catalogue the loss of biodiversity within the state. Biodiversity is key to the existence of ecosystems. Healthy ecosystems exist in a state of dynamic equilibrium, where as all species are stable in their populations. Change is accounted for and less threatening to any one species in such a state. Destroying one species habitat may completely eradicate that species. One recently eradicated species was a certain species of butterfly, the only butterfly which eats a certain kind of generalist mosquito. Without that butterfly controlling the mosquito population, the mosquitoes are now spreading diseases through many animals, including humans. Loss of biodiversity means loss of stability, not just for certain species but for all, including humans.

There are five terrestrially based habitats in Ohio. Each is unique of the others, however, they all share a similar and frightening reality, they have all been diminishing in size, number, and fitness. The following is short description of each of the habitats.

Ohio's Urban Landscape

Ohio's urban landscape is land that has been very transformed by human encroachment. Lots of pollutants are given off from the different urban landscapes that exist. Pollutants such as household runoffs, landscaping and commercial fertilizer usage, pet wastes, leaves, grass clippings, and faulty on-site septic disposal systems must be maintained regularly going by particular standards created by the EPA. The Ohio EPA has main regulatory control over urban storm water. The ODNR defines standards for contractors, engineers and developers regarding the abatement of soil erosion and degradation of the waters. Many different plans and measures are taken to try and control as much of the pollutants as possible because of the large amount of them that are naturally created by the urban landscape design.

Ohio's Wetlands

Wetlands were considered to be wastelands for over 200 years. People viewed them as unproductive parcels of land. The idea was to either fill them up or drain them out to make them more useful. Federal laws enacted in the 1800s encouraged landowners to convert wetlands for agricultural production. Until as recently as 1986, federal tax laws gave allowance to farmers to deduct the cost of wetland drainage as a farm improvement expense.
Today, on the other hand, wetlands are viewed as valuable land that needs to be protected and managed for more growth. State and federal funds are available to restore them. Due to the mass destruction of wetlands between 1780 and 1980, 60 acres of wetlands were lost every hour. Approximately 90% of what were previously wetlands (5 million acres worth) have now been converted to other land uses, primarily for agriculture and commercialÊ
uses.

Ohio's Prairie Grassland Habitat

The origin of Ohio's prairie grasslands begins after the last glacial period when dry climatic conditions prevailed favoring the expansion of the western prairies eastward into Ohio. Later as the climate became more humid, hardwood trees invaded from the East. The prairie with the aid of fire held off the advance of these trees for a time. By the time of pioneer settlement, western Ohio prairies were fragmented into islands surrounded by forest. When pioneer farmers discovered these prairie islands, they were quickly transformed into cropland and pasture. Today less than 1% of Ohio's original prairie remains. There are fewer acres of native prairie than native wetland. Ohio's prairie grasslands are the most endangered natural landscape. This loss is landscape has resulted in the lack of habitat for and therefore results of extirpation for animals such as the prairie chicken and the woodland bison. Many grassland birds have also declined in recent years due to the lack of their preferred natural landscape. Although they have somewhat adjusted to the loss of prairie habitat by adapting to the non-native surrogate pastures and hay land planted by farmers which is also at a shortage.

Ohio's Forest Habitats

Before the Europeans settled in Ohio there was 95% of forestland covering Ohio's landscape. Pioneers in their settling altered woodland habitat by cropland conversion, overgrazing, residential and industrial development and commercial timber harvest.

Today 33% of Ohio's land is considered woodland. Woodlands in Ohio typically range from 5 to 50 acres. In the past when woodland was more common animals such as elk and woodland bison existed. Today endangered animals such as the Indiana bat, bobcat, eastern wood rat and the timber rattlesnake dwell in woodland habitat. Birds are one of the largest groups of animals that use woodland habitat. All of Ohio's 22 species of salamanders need woodland habitat for an essential part of growth in their life cycle. Almost half of Ohio's wildlife species require woodland habitat. The largest trees that dwell in the habitat define Woodland types. The trees that may dwell there are oak-hickorys, Beech-Maples, Elm-Ashes and successional hardwood types. The age/maturity of the woodland habitat defines what animal species may be attracted to dwell there. Forest fragmentation and conversion to other land uses are major problems affection the woodland wildlife populations. Patchy woodlands typically support a poor diversity and exclude species that require large blocks of unbroken woodland habitat altogether.

Ohio's Riparian Habitat

Riparian habitat is land and vegetation that is situated along the bank of a stream or river. So the existence of the Riparian habitat may change constantly due to changes in physical structure and plant composition that comes from fluctuating water levels in this habitat. Riparian habitat mainly consists of plants, mainly woodlands, and smaller microhabitats with button brush thickets, seasonal spring pools, sedge meadows and cattail marshes. This type of habitat promotes the dispersal of different wildlife populations. This habitat maintains especial importance for quail because of their lack of strong mobility skills to get to a sage and viable habitat. The Riparian habitats help them to safely passage through to where they need to go. They are also very good habitats for migrational pit stops because of all of their natural resources.

Like Wetlands the Riparian habitats have been mistreated and many of them were destroyed. Protection and restoration are the next steps that need to be taken in order to keep these very essential habitats in tact for our wildlife. Luckily, they can naturally be restored by themselves if given the opportunity to revert back into their original habitat environment.

The loss of Ohio's wetlands has been a leading cause to wildlife endangerment. Already over 90 percent of Ohio's wetlands have been drained for agricultural use, or residential and urban development. Several endangered species requiring this type of habitat include: river otters, copper-belly water snakes, osprey, and sandhill cranes. The Ohio landscape has been stripped of its original temperate forests over the last two hundred years of development and agricultural expansion eliminating species such as mountain lions and timber wolves. Since the 1940's some previously lost forest has been recovered and consequently restoring populations of white-tailed deer and Eastern wild turkey.

Contamination by harmful chemicals continues to be a problem for Ohio's wildlife. Widespread DDT use was a leading cause in reproductive malfunction of Ohio bald eagles. This is due to several effects. DDT was used on many fields and other areas unintentionally also spraying mice and other such small animals. The bald eagles would eat these animals, thus biomagnifying an already very deadly substance from small traces in one animal to larger quantities in the bald eagles. After a period of bioaccumulation within the eagles and their species the DDT began to prevent healthy hatchlings or fertilizing at all thus dramatically reducing the population in a short time. Upon the discontinuation of DDT usage the bald eagle population has been on the rise ever since. Degradation of Ohio's natural waters has culminated to such an apex that the majority of Ohio's endangered species list consists of aquatic species. Some causes of the degradation are due to siltation, poor water quality from acid mine drainage, industrial, agricultural, and municipal sewage discharges, and stream channelization. As obvious from the list of causes and effects, habitat loss is a major threat to many species. Protection and restoration of these habitats is key to the survival or reintroduction of many species. Several programs to accomplish this daunting task have already been initiated and are working with respectable success. Although most of these areas can only be considered as "islands of nature", which have been historically and scientifically proven to be ineffective in the long-run of saving species, it is still a step in the right direction.

RESEARCH DESIGN

Our research is designed to analyze the data received from the Ohio Department of Fish and Wildlife pertaining to endangerment, extipated, threatened, or of special interest. As opposed to studying specific species within categories we have decided to study generalized species including mammals, fish, birds, mollusks, amphibians, and reptiles. This research will provide us with comprehensive data on the quantity of of generalized species within each listing category over the time period in which Ohio has been gathering data. From this data we will construct two separate kinds of graphs demonstrating change over time within all categories, and how change in one category effects others. We can then divide these graph categories and construct several different graphs for each generalized species and totals derived from our data. Through this process we will show how one species recovery or decline affects another, what impact past environmental conservation efforts have made, and possible future predictions for generalized species survival.

The research is designed to measure the rate at which species are being added or removed to the endangered species list over the course of the last thirty years. This provides a generalized picture of the state of biodiversity and wildlife management in the state of Ohio.

MATERIALS AND METHODS

Using data from the Ohio Department of Natural Resources and other sources, we will compile a comprehensive list of the various species that are threatened, of special interest, and endangered. We wish to include the population counts as well as general ecosystem location.

Through our species count/analysis in addition to to the research on ecosystem destruction or restoration we will be able to test our hypothesis.

The first data set will start with the first published list of endangered species in 1974. Lists are published every two years to keep the data updated. Fairly precise data has been kept on these species to track their numbers and fitness. The data we compile will be used to chart the population declines or increases of various species'. This will provide a graphical representation of the loss of biodiversity.

Since habitat loss is the most crucial factor in species endangerment and extinction, we will attempt to correlate the loss of certain types of species with the loss of certain habitats.

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RESULTSÊÊ

Upon examining and updating the comprehensive list of extinct, extirpated, endangered, threatened, or of special interest we have obtained the following results.ÊFrom the updated list we obtained the following data. Click here to see the data. It is a numerical representation of the number of species that are endangered, threatened, or of special concern.

This graph shows the changes in the percentage that each of the chordata sublists have undergone since 1974. The totals include only those species listed as endangered.

This is a numerical representation of the changes in the number of endangered species
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This graph shows the changes in the percentage that each of the chordata sublists have undergone since 1974. The totals include only those species listed as threatened.

This is a numerical representation of the changes in the number of threatened species

This graph shows the changes in the percentage that each of the chordata sublists have undergone since 1974. The totals include only those species listed as of special concern.

This is a numerical representation of the changes in the number of species of concern

This data chart displays the most current data on the percentage amount of listed species as they compare to the total number of species within a given chordata. This table shows the current number of species within a given chrodata that are on the Ohio lists. These numbers are really quite amazing. All in all, 174 out 610 major species are endangered, threatened, or of special concern. Thats just under 30%.

A graphical representation of the data table above.
In analysis of the Percent of Total Species Endangered graph, one notices that reptiles and amphibians together never total more than twelve percent. According to the related line graph, no more than 5 reptiles or amphibians were ever listed as endangered. One will also notice that fish comprise the highest percentage until 1990 at which point it falls to approximately 30% and remains steady throughout while mollusks and birds are then much higher in percentage. The corresponding line graph shows that while there were almost 40 bird species listed as endangered until 1990, afterward they dropped to 25 while, birds and mollusks jumped to 25, and then to 29 and 28 respectively. This change could be due to a shift in focus from primarily fish, to incorporating other species such as the now noticeably declining birds and mollusks. Unfortunately no data was recorded before 1990 in terms of special interest or threatened species, so analysis relies solely on the years following. In 1990 birds were king of the special interest category comprising more than 30% with 18 species of all special interest species. That number is double all other general species categories with the exception of fish, which were at the time the most endangered species category. Fish were kept as a primary special interest category partly because so many had been recently taken off of the endangered species list but should still be watched. From 1990- 2002 no generalized species increased or decreased more than 10% in special interest. In terms of threatened species, neither amphibians nor mammals even made it onto the list. Reptiles, although making it on the list, only had one species listed until 2001 when another was added raising the total to two, and their percentage to 6%. By far the most threatened species was the fish. Starting at 8 species and ending in 2002 with 13, and consuming almost 50% of threatened species in the beginning and full 50% today.Ê

Through analysis of the endangered, special interest, and threatened species totals one thing is apparent. Either endangered species are kept track of much closer, or many species go strait to the endangered list without stopping at the other precursor lists. With the introduction of the non- endangered lists; the amount of species previously on the endangered list fell to a low 60 species listed. In the fallowing years it again rose to high nineties until falling in 2001 to low eighties as the special interest and threatened species lists rose to 45 and 30 species represented respectively.Ê

This raises the question as to whether these lists draw attention to other species which are not endangered but do deserve to be watched, or if the other lists merely remove species from the endangered species list. Some questions for further research may be: Why these lists were created? How much time and resources go into data collection for the endangered species list as compared to the special interest, and threatened species? For future study, what impact did these other lists have on conserving and saving species?

SOURCESÊ

Chapin, F. Stuart III et al. Consequences of Changing Biodiversity. Nature. Vol 405. May 11, 2000. pp. 234-243Ê

Demers, Michael N. et al. Fencerows, Edges, and Implications of Changing Connectivity Illustrated by Two Contiguous Ohio Landscapes. Conservation Biology. Vol. 9. Issue 5. Oct 1995. pp.1159-1168.Ê

Fagan, William; Cantrell, Robert; and Chris Cosner. How Habitat Edges Changes Species Interactions. The American Naturalist. Vol. 53, No. 2. 1999. pp.165-182.Ê

Mooney, H.A. and Cleland E.E. The Evolutionary Impact of Invasive Species. PNAS. May 8, 2001. pp. 5446-5451.Ê

Paul, Michael J. and Judy L Meyer. Streams and the Urban Landscape. Annual Review of Ecological Systems. 2001. Vol. 32. pp. 333-365.Ê

Pimm, Stuart L. and Askins, Robert A. Forest Losses Predict Bird Extinctions in Eastern North America. Proceedings of the National Academy of Sciences of the U.S.A. Vol. 92, Issue 20. Sept. 1995. pp. 9343-9347.Ê

Pimm, Stuart. How Many Species Will We Lose? A Conversation. www.envreview.igc.org/pimm.html

Quammen, David. The Weeds Shall Inherit the Earth. The Independent. London, November 22, 1998. pp. 30-39.Ê

Sexton, Owen J. Replacement of Fox Squirrels by Gray Squirrels in a Suburban Habitat. American Midland Naturalist. Vol. 124, Issue 1. July 1990. pp. 198-205

Wolff, Jerry O. The Role of Habitat Patchiness in the Population Dynamics of Snowshoe Hares. Ecological Monographs. Vol. 50, Issue 1. March 1980. pp. 111-130.Ê

Western, David. Human Modified Ecosystems and Future Evolution. PNAS. Vol. 98, No. 10. May 8, 2001. pp. 5458-5465