IUCN: The World Conservation Union Education Unit

BIODIVERSITY: A holistic view
Suryya Khatoon¹ and Qadeer M. Ali²
1Department of Botany, ²Marine Reference Collection and
Resource Center, University of Karachi

The words ‘Biodiversity’ and ‘Ecosystem’ are quite fashionable nowadays, but these terms are still remain largely misconceived in many minds despite their frequent use. Biodiversity and ecosystem are not remote or abstract things; these are all around and as a matter of fact, we are all part of them.

The vastness of the term ‘biodiversity’ (coined in 1980s) is unmatched in all scientific terminology. It refers to the entire variety of life on Earth, i.e. all species of living organisms, the genetic diversity within each species, and the variety of the ecosystems which they are part of. Although this term and its comprehensive definition are rather new, biodiversity in itself is not anything new. It originated 3.5 billion years back with the origin of the first organism on Earth and the variety of life today is product of 3.5 billion years of the evolution of Life. It is Interesting that out of 4.75 billion years of the total age of Earth, the atmosphere had been devoid of oxygen (and thus of ozone layer) for about 4 billion years. It acquired the O₂ level similar to the modern level about 400 million years before present, accompanied by the formation of ozone layer (O₃ – a molecular variant of oxygen). The earliest organisms on Earth were therefore anaerobic bacteria and in the absence of ozone, the only chance of their survival was under water. The evolution of life on land is only 400 – 500 million years old compared to 3.5 billion years in water. This explains the enormous diversity of life in the oceans.

Where did the atmospheric oxygen come from? The only process responsible for it is was photosynthesis. This single process (i.e. the use of solar energy for synthesising carbohydrates by the chlorophyll-bearing organisms accompanied by the liberation of oxygen) has been responsible for the present shape of life, and is still sustaining all forms of life on Earth. Only plants can convert the inorganic substances into organic matter, which could be used as food by animals including humans. This is why the earth origin of plants on Earth preceded that of animals, which originated only when sufficient amount of organic matter became available in the environment.

Every region of world has its particular set of plant, animal and microorganism species (collectively called biota) according to its local climate and geology; all inter-dependent and balancing each other’s population, thus forming the ecosystem. The biotas of all parts of the world form Earth’s total biodiversity. It is notable that in any ecosystem, plants being the primary producers play the pivotal role. The natural fauna of a land evolves according to its indigenous wild plant species. On an average, the extinction of one plant species means the extinction of 15-20 species of associated animals (including insects).

Why to conserve biodiversity?

One of the reasons is ethical. All these species on Earth have not been created by man and he does not have a right to eliminate something, which he cannot create. The world Charter for Nature adopted by the General Assembly of UN in 1982 emphasises that "every form of life is unique, warranting respect regardless of its worth for man" and "it should be protected for its own sake". However, it is not all idealistic; bio diversity has pragmatic value too. …Continue

Almost all needs of human kind are met by the resources obtained from plants, animals and microorganisms. All is still not known about Earth’s biodiversity. The total species on Earth are estimated to be near 13-14 million of which only 1.75 million have been scientifically identified and named. Out of these hardly 3% are the cultivated plants and domesticated animals, i.e. a very great fraction of biodiversity has not been explored for its potential benefits. The pressure of increasingly human population has accelerate the specimen extinction rate by 100 – 1000 times and a large number of species would go extinct without being ever known. That means that the loss of unique gene combinations and unknown potentially useful substances forever. It is important to understand that the ecosystems are integrated entities where all species act synergistically; the loss of any species disturb the ecological balance which eventually directly or indirectly affects the quality of human life.

Services provided by the ecosystems:

Humankind takes it for granted but the services provided by the natural ecosystems if assessed in monetary terms, amount of billions of dollars. Some of the ecosystems could be highlighted as follows:

Forest ecosystem:

Besides providing timber and fire wood, the forest floor vegetation provides valuables non-timber resources like medicinal plants. The forests act as sponge for absorbing the heavy rainfalls and later releasing the water into streams and rivers. Destruction of forest results in worst floods not only due to lack of absorption but also by shoaling of rivers due to eroded soil in the absence of vegetationl cover. The increased intensity of Bangladesh floods in recent years is attributed to the deforestation in the upper reaches or the major river: resulting in their shoaling in Bangladesh.

Coastal ecosystems:

In the tropical and subtropical parts of the world, Mangroves are the most significant component of the coastal ecosystem. There are about 24 million hectares of mangrove forests world over, containing some 50 – 60 mangrove species. Their greatest concentration is in Indian Ocean to W. Pacific region, i.e. from Bangladesh to Australia and Philippines. Pakistan is unique in having the largest area of arid climate mangroves in the world, with about 160,000 hectares in Indus delta and 9175 hectares along Balochistan coast fringing the lagoons and bays like Miani Hor, Kalmat Khor and Gwater Bay. Mangroves have peculiar adaptations for surviving in highly saline and unaerated mud. This ecosystem thrives on the basis of receiving silt and nutrients brought by the rivers and releasing organic matter towards sea. In doing so, they not only protect the coast line from sea erosion and cyclones, but actually build and extend it by trapping the sediment in their roots. The shelter and organic matter provided by them attracts a variety of fauna including birds, fish, crustaceans, molluscus, etc. They actually act as natural spawning grounds for fish and other marine animals, which feed on their foliage. The fish and Crustacea species associated with Sindh-Balochistan coast mangroves includes Paplet (white pomfret- Pampus argenteus), Surmai Scomberomorus commerson & Rastrelliger kanagurta, Dangri (Lates calcalifer), Hira (Lutjanus argentimaculatus), Palla (Tenvalosa ilisha), shrimps (Metapanaeus affinis & Parapanaeus stylifera), Mud crab (Seylla serrata) etc. Any damage to the mangroves means damage to all these associated species resulting in great economic loss. The indigenous people totally depend upon mangroves for building materials, firewood and livestock feed. …Continue

As with other wetlands, mangrove forests had long been disliked by general public and planners considering them filthy wastelands, breeding grounds for mosquitoes and other nasty creatures.

With the expansion in the realm of scientific knowledge the opinions are now changing world over and it is being recognised that the sustainable utilisation of wetland resources is more beneficial to economy and environment, rather than filling or draining-off the wetlands for other purposes. In our country, unfortunately the real worth of mangrove forests is still not appreciated. The reduced amount of fresh air in the Indus delta due to the construction of dams has already resulted in the extinction or near extinction of about six mangrove species viz. Aegiceras corniculatum, Bruguiera conjugata, Ceriops raxburghiana, C. tagal, Rhizophora apiculata, and Sonneratia caseolaris. Now our mangrove forests are largely formed by a single species, i.e. Avicennia marina. Besides mangroves, a wild species of rice (Oryza coarctata) used to grow in the Indus delta, a free –of-cost source of grain for the local population. The lack of fresh water greatly diminished this species also and it is no longer used as a grain source. Our think tanks, planners and politicians need to be more conversant with the value of this natural resource, which ought to be conserved for the future generations.

Desert ecosystems:

Although the deserts and drylands to do not have too many tree species, still they are rich in biodiversity especially the seasonal grasses and other herbaceous vegetation, and the associated insect species. The importance of natural vegetation for the desert dwellers is perhaps greater than in any other habitat. Their main asset, live stock herds live on the desert vegetation. Besides this, thatching materials and many indigenous medicines are obtained from the wild plant species. Any damage to this vegetational cover deteriorates the already difficult conditions of the desert resulting in famine and migration.

Top soil: The ultimate resource

Though seldom appreciated, the ultimate resource for everything on Earth is soil. Every terrestrial ecosystem functions on the basis of recycling of materials. The plants obtain nutrients form soil, synthesise biomass utilising these nutrients along with water, CO₂ and solar energy return these resources with profit to the soil after their death and decay. The animals consume the plants and return these nutrients to the soil after death and decomposition. The invertebrate fauna (like earthworms) and microorganisms perform the recycling process, which adds organic matter to the soil. This not only enriches the soil but also maintains its porous structure necessary for the proper growth of plant roots. This fertile layer of soil i.e. the topsoil is not very deep, could be just few centimetres in drylands. Besides providing numerous other services, every natural ecosystem performs the basic important function of nurturing and protecting the topsoil. Any damage to topsoil results in the collapse of the ecosystem and eventually desertification. In the cultivated lands, the natural recycling process stops and with every harvest, soil keeps on losing its fertility and structure resulting in land degradation, erosion and desertification.

Reasons for the loss of Biodiversity:

One of the very obvious reasons is over-exploitation of living resources. The selective elimination of certain species in persecution or introductions of any alien species also disturb the ecological balance ultimately resulting in the loss of biodiversity.

However, the greatest loss to biodivesity occurs through the modified land use, which means the destruction of natural habitats of plants and animals. Unlike other species, human species modifies the environment according to its needs rather than adapting itself to the natural environment. All the lands occupied by cities, roads, farms, etc were once natural ecosystems like forests and grasslands. Land use for human food production now occupies over one-third of the world’s total land surface (11% cropland + 26% permanent pasture).

Measures for conservation:

Various international conventions on the protection of natural flora and fauna had been formulated in past two decades like Ramsar Convention Bonn Convention, CITIES, etc. However, the most comprehensive of all is the Convention on Biological Diversity (CBD) adopted at Earth Summit (June 1992) in Rio de Janeiro, hitherto ratified by more than 120 countries. The major stress of CBD is on the in situ conservation in addition to ex situ conservation, i.e. the conservation of species in their natural habitats. This includes the establishment of protected areas like National Parks, wildlife sanctuaries, etc. In any case, only the protected areas are not an answer to biodiversity loss; because all species of a region can never be represented in the protected areas only. Many occur outside the protected areas like along roadsides or around cultivated lands, due to their specific ecological requirements. Only a feeling of respect for nature can ensure maximum conservation, Only a feeling of respect for nature can ensure maximum conservation, which has started to arise at least in some places. In Britain, some farmers are now leaving uncultivated boarders around fields for weeds and insects; the rich flora and fauna developed along Berlin Wall has not been bulldozed after the demolition of Wall; the National Wildlife federation (USA) is promoting the creation of habitats for indigenous plant and animal species on college campuses nation-wide. Such activities can compensate to some extent for what had been lost in past ignorance.

Biodiversity in the perspective of Pakistan

The concepts of environmental protection and conservation were imported here few years back but unfortunately still remain largely misconceived. Two major misconceptions have played havoc onto the natural ecosystems:

1. Only trees are important and other forms of plant life like herbs and shrubs are "unwanted, useless growth", therefore the tree-plantation campaigns regularly involve the removal of all natural vegetation from land’s surface, and
2. Only cultivated plants are important and eliminating wild plants is a service to the environment, therefore all the "cleanliness" drives involves hoeing and bulldozing the natural vegetation, which not only destroys the biota but also damage the topsoil and causes erosion through wind. The Karachi University Campus is a pertinent example. The campus with an area of more than 1200 acres was an extremely rich habitat, perhaps the richest in entire southern Sindh, had more than 400 wild plant species and an unknown number of insect, bird and herbivore species. The administration launched a cleanliness and beautification and tree-plantation drive" in 1994 which involved wholesale and continual destruction of natural vegetation through hoeing and bulldozing which not only destroyed this natural heritage but also increased the atmospheric dust pollution due to wind-erosion of exposed loose soil. The same exercise could be seen in all the open spaces and along the highways, which is a gross violation of CBD, ratified by Pakistan. Even the forest departments do the same that is bulldozing the land for afforestation with some selected species and subsequent removal of regenerating wild plants considering them harmful for the trees. As a matter of fact, no natural forest is without undergrowth, which is an integral part of that ecosystem and protects the topsoil. …Continue

All the ingenious plant species had been documented in the " Flora of Pakistan" published by the Department of Botany, University of Karachi and PARC, however there is no zoological counterpart. Some of the endangered species like houbara bustard, ibex, snow leopard, green turtles etc. are highlighted from time to time; but in the absence of any comprehensive monitoring system, no one knows how many indigenous plant species and invertebrates have become extinct or endangered during past few years due to the onslaught on natural ecosystem. Only in Karachi division, over a dozen plant, species have gone extinct and more than tow dozens are highly threatened including some endemic ones.

As required by CBD, the Biodiversity Action Plan for Pakistan (BAP) has been prepared in January 1998. This involved huge expenditure in the heads of seminars and visits by foreign experts. It is a nice document; but is it sufficient to be a nice document? The Action 6.6 of BAP calls for measures to control invasive alien species and to prevent further introduction, the Action 7.2 calls for the creation of more diverse forest plantations using indigenous species and to incorporate biodiversity concerns into forest management plans. On the contrary, our forest departments are zealously planting Eucalyptus and other alien species, mostly in monocultures. Some time back the Sindh government announced its plan to plant 8 million Eucalyptus tree in Sindh. It is surprising that any conservation organisation like IUCN or WWF not uttered a single word on it. It is interesting to note that a country like Mozambique banned Eucalyptus in 1996 on grounds of damage to the environment and opted for an ecotourism project instead.

The Action 17.4 of BAP calls for the integration of biodiversity themes in tertiary level courses. Despite this, most institutions awarding degrees in environmental sciences are not offering any course on biodiversity. The Action 21.1 calls for detailed rules to include a checklist of activities likely to have adverse impact on biodiversity in Environment Impact Assessment (EIA) reports of developmental projects. In spite of this, qualified botanists and zoologists are not being involved in preparing EIA reports, and flora and fauna are just mentioned as "shrubs, trees, cattle", etc. without any scientific inventorying.

In the absence of effective implementation, does BAP have more than a face value?

Despite the pivotal role of wild plants in the natural ecosystem, there is no Botanical Survey Department in Pakistan neither a single Botanical garden, including an utter negligence towards this most important component of biodiversity.

Understanding, identification, monitoring and conservation of biodiversity have a far-reaching and long-term bearing on the future prospects of humankind’s survival and quality of life on this planet. It is biodiversity that makes the ecosystems which we are part of. Any harm inflicted onto biodiversity means damage to the ecosystem which eventually directly or indirectly exerts negative impact on the quality of human life.

Captions for the photographs

1. Insect-plant relationship is the strongest mutualism between any two groups of organisms. This species of butterfly is found mostly on Helliotropium ramosissimum, an indigenous plant species.
2. Although birds find shelter in trees, but most of them feed on the seeds and grains of smaller plants, as this bird feeds on the grains of Lasiurus scindicus, a dryland grass species.
3. A healthy stand of Avicennia marina at Jiwani, with trees up to 3 meter tall.
4. The mangrove forest at Sindh-Baluchistan coast provide refuge to the migratory birds.
5. The lush green plants uprooted and heaped in "cleanliness" drive exposing the soil to erosion.
6. Monsonia senegalensis: the only habitat of this extremely rare species was on the Observatory hillock in the University campus which has been destroyed in the beautification process of that hillock. Now this species has become extinct in Karachi Division.