Bio- and landscape diversity: Theme # 5 Theme

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Bio- and landscape diversity: Theme # 5 Theme 5: Species diversity • What is species and species diversity • Population and its diversity • Minimum viable population • Rare species • Endemic species • Umbrella species • Flagship species

Bio- and landscape diversity: Theme # 5 What is species and species diversity In biology: a species is a group of interbreeding natural populations unable to successfully mate or reproduce with other such groups, and which occupies a specific niche in nature (Mayr, 1982; Bisby and Coddington, 1995); a species is a group of interbreeding natural populations that is reproductively isolated from other such groups (Mayr, Ashlock 1991) Biodiversity is frequently expressed as the total number of species currently living on Earth. Between about 1. 5 and 1. 75 million species have been discovered and scientifically described thus far. Scientists expect that the scientifically described species represent only a small fraction of the total number of species on Earth today. Many species have yet to be discovered, or are known to scientists but have not been formally described. Scientists estimate that the total number of species on Earth could range from 13 up to 20 million, and some scientists give much wider range: from about 3. 6 million to 117. 7 million. Most public attention is focused on the biology and ecology of large, charismatic species such as mammals, birds, and certain species of trees (e. g. , mahogany, sequoia). However, the greater part of Earth's species diversity is found in other, generally overlooked groups, such as mollusks, insects, and groups of flowering plants. Most number of species belong to mollusks, insects, and flowering plants

Bio- and landscape diversity: Theme # 5 What is species and species diversity Estimated Numbers of Described Species (based on Lecointre and Guyader, 2001) Taxon Common Name Number of species described % of total number of described species Bacteria true bacteria 9021 0. 5 Annelida annelid worms 14360 0. 8 Archaea archaebacteria 259 0. 01 Nematoda nematode worms 20000 1. 1 Bryophyta mosses 15000 0. 9 Arachnida arachnids 74445 4. 3 Lycopodiophyta clubmosses 1275 0. 07 Crustacea crustaceans 38839 2. 2 Filicophyta ferns 9500 0. 5 Insecta insects 827875 47. 4 Coniferophyta conifers 601 0. 03 Echinodermata echinoderms 6000 0. 3 Magnoliophyta flowering plants 233885 13. 4 Chondrichthyes 846 0. 05 Fungi fungi 100800 5. 8 cartilaginous fishes "Porifera" sponges 10000 0. 6 Actinopterygii ray-finned bony fishes 23712 1. 4 Cnidaria cnidarians 9000 0. 5 Lissamphibia living amphibians 4975 0. 3 Rotifera rotifers 1800 0. 1 Mammalia mammals 4496 0. 3 Platyhelminthes flatworms 13780 0. 8 Chelonia living turtles 290 0. 02 Mollusca mollusks 117495 6. 7 Squamata lizards and snakes 6850 0. 4 Aves birds 9672 0. 6 193075 11. 0 Other

Bio- and landscape diversity: Theme # 5 What is species and species diversity Most of the unclassified species on the Earth are invertebrates. This group of organisms includes insects, spiders, mollusks, sponges, flatworms, starfish, urchins, earthworms, and crustaceans. These species are often difficult to find and identify because of their small size and the fact that they live in habitats that are difficult to explore. In the tropical rain forest, the cataloging of species has been quite limited because of this later reason. Scientists estimate that this single biome may contain 50 to 90% of the Earth's biodiversity. Numbers of Described Species (generalized taxa) Groups Cataloged 827 000 species are insects Estimated Total 1. 4 million 5– 50 million Mammals 4, 000 90– 95% Reptiles and amphibians 10, 848 90– 95% Birds 9, 040 94– 100% Fish 19, 056 83– 100% Plants trees 322, 311 (50, 000) 67– 100% Invertebrates 1, 020, 561 3– 27% Microorganisms 5, 760 3– 27% 322 000 species are plants 41 000 species are vertebrates

Bio- and landscape diversity: Theme # 5 Population and its diversity Population is the collection of inter-breeding organisms of a particular species that could easily mate with each other. Diversity of individuals within a species is determined by its age and gender structure. Diverse population is composed with individuals of different age groups and of different sex. Age distribution – the diverse population should have individuals of various age groups. However, to keep the population vital and to maintain its genetic diversity the expanding type of age distribution is preferable. Contracting type population pyramid (mature individuals prevail over young individuals) indicates on high risk of extinction of population. Basic types of population pyramids Sex distribution – depends on mating behavior of species. For many distribution species (e. g. mammals) 50 -50% distribution among males and females is the best; while for others females should prevail (e. g. for many insects)

Biodiversity: Theme # 5 Minimum viable population Small and isolated populations are particularly vulnerable to extinction through random variation in birth and death rates, variation in resource or habitat availability, predation, competitive interactions and single-event catastrophes, and inbreeding. The smaller population is the higher the risk of its extinction would be. Minimum viable population (MVP) is the smallest possible number of individuals in the population at which a biological population can exist without facing extinction from natural disasters or demographic, environmental, or genetic stochasticity. Drop below the MVP size will dramatically increase the risk of extinction of the population. The term Minimum Viable Population has come into wide usage because the U. S. Forest Service was enjoined by Congress in 1976 to maintain "viable populations" of all its native vertebrate species in each National Forest. Minimum Viable Population is usually estimated as the population size necessary to ensure between 90 and 95 percent probability of survival between 100 to 1000 years into the future. Each species has its own MVP size. For terrestrial vertebrates an MVP of 500 to 1000 individuals has often been given when inbreeding or genetic variability is ignored. When inbreeding effects are included, estimates of MVP for many species are in the 1000 s. Based on a reported values in the literature for many species, a median MVP is equal to 4169 individuals. A population may be increased above the MVP using a captive breeding program, or by bringing other members of the species in from other reserves.

Bio- and landscape diversity: Theme # 5 Minimum viable population: example Each species has its own MVP size, and the estimates of MVP which is about 1000 s are mostly for vertebrates. For other taxa the MVP size is normally much bigger. For example, for Bay checkerspot butterfly, endangered species in California, this size is about 100 000 s. Minimum viable population sizes and probability of persistence for Bay checkerspot butterfly No of years Probability of population should persistence persist 50 1, 394, 102 95% 258 762 427 1000 Euphydryas editha bayensis 90% 100 Bay checkerspot butterfly Minimum viable population size 99% More than 1 trillion

Bio- and landscape diversity: Theme # 5 Rare species A rare species which are very uncommon or scarce. Although there are no strict and officially recognized criteria for designation of a rare species, the rare species are generally considered as species whose number of individuals is very small worldwide, usually less than 10 000. However the concept of rarity is also influenced by having a very narrow endemic range and/or fragmented habitat. Designation of a rare species may be made by an official body such as a national government, state or province. The Whooping Crane (Grus americana), the tallest North American bird is very rare species. As of April 2007 there were about 340 whooping cranes only. Examples of very rare mammal species Species Number of remaining individuals Yangtze River Dolphin A species may be endangered or vulnerable, but not considered rare if, for example, it has a large, dispersed population but its numbers are declining rapidly or predicted to do so. Rare species are generally considered threatened simply because the inability of small population sizes to recover from stochastic events, and the potential for a rapid decline in population. only a few tens of individuals Javan Rhino fewer than 60. . . Hispid Hare (Assam Rabbit) 110 Tonkin Snub-nosed Monkey about 200 Yellow-tailed Woolly Monkey fewer than 250 Sumatran Rhino fewer than 300 Ethiopian Wolf about 500 adults Giant Panda about 1000 Golden Bamboo Lemur about 1000 and many others

Bio- and landscape diversity: Theme # 5 Endemic species An endemic species is one that is only found in a particular region and nowhere else in the world. For example, many species of lemur are endemic to the island of Madagascar Since these species are not widespread and may be confined to only one or two protected areas, they are of great conservation concern. Endemism is the ecological state of being unique to a particular geographic location, such as a specific island, habitat type or other defined zone. Physical, climatic and biological factors can contribute to endemism. For example, the Orange-breasted Sunbird is endemic to Fynbos, meaning it is exclusively found in the Fynbos vegetation type of southwestern South Africa. Endemic types or species are especially likely to develop on islands because of their geographical isolation. This includes remote island groups, such as Hawaii, the Galápagos Islands, and Socotra. Endemism can also occur in biologically isolated areas such as the highlands of Ethiopia, or large bodies of water like Lake Baikal. For example, almost 900 species of birds, about 90% of all bird species, are endemic to oceanic islands. The native flora of the Hawaiian archipelago is estimated to have originally contained 2, 000 species of angiosperm plants, of which 94 -98% were endemic. Similarly, 76% of the plants of the Pacific island of New Caledonia are endemic, as are 50% of those of Cuba, and 36% of those of Hispaniola. Galapagos land iguana, Conolophus subcristatus Galapagos Islands, Ecuador Galapagos penguin, Spheniscus mendiculus Galapagos Islands, Ecuador Great white shark, Carcharodon carcharias Guadalupe Island, Mexico

Bio- and landscape diversity: Theme # 5 Endemic species Because endemic species have geographically restricted distributions, and they have often evolved in isolation from many types of diseases, predators, and competitors, they tend to be highly vulnerable to extinction as a result of the activities of humans. Endemics can easily become endangered or extinct because of their restricted habitat and vulnerability to the actions of man, including the introduction of new organisms. About three-quarters of the species of plants and animals that are known to have become extinct during the past few centuries were endemics that lived on islands. For example, of the 108 species of birds that have become extinct during that period, 90% lived on islands. About 97% of the endemic plants of Lord Howe Island are extinct or endangered, as are 96% of those of Rodrigues and Norfolk Islands, 91% of those of Ascension Island, and 81% of those of Juan Fernandez and the Seychelles Islands. Tremendous numbers of endemic species also occur in the tropical rainforests of continental regions. Most of African lungfish, these species are now endangered. Protopterus annectens Seychelles Green Frog Since European colonisation, about 10 per cent of Australia's endemic mammals have become extinct. In fact, almost half the mammals that have become extinct globally in the last 200 years were Australian. Ecoregions with high endemism • Hawaiian tropical forests • Madagascar dry deciduous forests • Madagascar lowland forests • New Caledonia dry and rain forests • Sierra Madre pine-oak forests (Mexico) • Luzon rainforests (Philippines) • Mindanao rain forests (Philippines) • Palawan rain forests (Philippines

Bio- and landscape diversity: Theme # 5 Flagship species are the species which have powerful iconic, symbolic meaning to people and due to this provide a focus for raising awareness and stimulating action and funding for broader conservation efforts. A flagship species is a 'charismatic' (symbolic) species selected to act as an ambassador, icon or symbol for a defined habitat, region, issue, campaign or environmental cause. Flagship species are closely connected with the sacral and symbolic value of biodiversity (see theme 3) Flagship species are chosen for their vulnerability, attractiveness or distinctiveness in order to engender support and acknowledgment from the public at large. Giant Panda, Ailuropoda melanoleuca Flagship species are usually relatively large, attractive and symbolic to nation or regional community. Flagship species are often keystone species and umbrella species. They also may be good indicators of biological processes and threats to biodiversity. By focusing on, and achieving conservation of flagship species, the status of many other species which share its habitat – or are vulnerable to the same threats - may also be improved. Examples of flagship species include the Asiatic lion and the Bengal tiger of India, the giant panda of China, the golden lion tamarin of Brazil, the African elephant, the mountain gorilla of central Africa, the orangutan of southeast Asia. . Royal Bengal tiger, Panthera tigris

Bio- and landscape diversity: Theme # 5 Flagship species The concept of a flagship species holds that by giving publicity to a few key species, the support given to those species will help to protect entire ecosystems and all species contained therein Saguaro cacti, flagship species for Arizona USA (Cacti have evolved in the desert environments of the Americas to become an important source of food and shelter for many different species. Of the 141 species of cacti on the IUCN Red List, 25 species are classified as Endangered and 27 are Critically Endangered) Polar Bear African elephant, Loxodonta africana

Bio- and landscape diversity: Theme # 5 Umbrella species are species whose protection helps to protect also many other species. The term was first used by Wilcox in 1984. The idea is that by protecting the important umbrella species and preserving its habitat, you'll also protect a number of other species that depend on the same habitat. Important requirements for a species to be considered as umbrella species include: Ш Large home range (for animals) or large occupancy area (for plants) Ш Diverse habitats Ш Wide requirements for food and other resources Ш High position in a food web (most of umbrella species are higher vertebrates) Umbrella species are used to select the locations of potential nature reserves, find the minimum size of these reserves, the distance between nature reserves. EXAMPLE: In Northern California, USA the bird northern spotted owl is a umbrella species for mixed forest because it has a wide home, wide (diverse) diet, and uses old trees for nesting. By protection the northern spotted owl we at the same time protect many other species including mollusks and salamanders as well as valuable old growth trees within a large area. Northern Spotted Owl, Strix occidentalis caurina

Bio- and landscape diversity: Theme # 5 New theme: Community diversity • What is community diversity • Abundance • Species richness • How to measure community diversity

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