On Preservation and Increasing the Populations of Pollinators
The discussion note on the subject provides an excellent, inclusive framework on which we may formulate a holistic strategy to preserve the bio-diversity among the pollinators, and to increase their populations.
Even though the composition of plant-pollinator networks may show a considerable variation even within a comparatively small area, the interrelationship among plants and pollinators in different networks seems to be remarkably similar.
This is fortunate, because it would enable us to develop a common generic strategy, which may be easily fleshed out to suit the local implementation. I will first take up what might cause the problem, and then will go on to consider how it may be resolved, provided that the requisite political will obtains.
Other things being equal, the decline in pollinator populations arises from any one or more of the following causes:
1. A critical reduction of either the food supply of the adult species, or its larval state for such a period of time, as a consequence of which it may be difficult to restore the previous population of a pollinator found in an area.
2. Introduction of toxic substances or food items into a pollinator’s habitat.
3. Increasing the exposure of a pollinator to its natural predators and/or pathogens.
4. Adverse climatic changes that may cause death.
Now, let us look at the human activities that seems to have brought about the four causes of population decline among pollinators. Critical food shortage may be directly or indirectly due to environmental degradation that reduces the number of types of plant species and/or their populations beyond the critical level necessary for the pollinators in the local plant-pollinator network to be sustained. First of these is a qualitative decline while the other is quantitative.
These two changes may be brought about by any one or more of the activities listed below:
I. Land clearance representing removal of natural vegetation from an area by mechanical means including the drainage of marshlands and water meadows for agriculture, building sites, roads and highways, and uncontrolled exploitation of forests etc., in a manner that makes it impossible for the local flora to re-establish itself.
II. Environmental pollution that brings about the same results as I above due to the use of certain agro-chemicals, and irresponsible discharge of toxic substances into the ground, streams or air by industrial installations.
III. Introduction of either too few types of food crops, or non-indigenous species that may seriously disrupt the inter-relationship among the members of the local plant-pollinator network. Please note that this may be caused by pollinators’ inability to recognise their flowers as a source of food due to their unfamiliarity.
IV. Adverse local climatic change due to denudation of plant cover, which renders it difficult for the local flora to re-establish itself.
As for the introduction of substances toxic to the pollinators, in addition to 1-II above, some plant species are known to produce nectar toxic to some pollinators (eg. some species of Linden to bees). Their introduction as foreign cultivars would be obviously detrimental to the local pollinators. Even more serious, since as early as 1999, pollen of a genetically modified variety of maize in the US has been known to be toxic to some pollinators.
While land clearance may promote the proliferation of pollinator pathogens because it may eliminate those species that helps to keep those pathogen populations under natural control, the changes in local climate that accompanies it may prove favourable to the proliferation of some pathogens, especially unseasonable spells of wet or humid weather.
Moreover, land clearance deprives pollinators of their protective plant cover, thereby making them more vulnerable to their natural predators, especially to the insectivorous birds.
I shall not suggest here how to resolve the deleterious effects of global warming on the pollinators. The former is an indirect result of the horrendous harm we have done to our environment by removing the indigenous plant cover from vast areas for things listed above, and our hardly rational emission of various greenhouse gases. Its resolution calls for a concerted world-wide effort outside our present brief.
The question then, is undertaking what generic strategic steps may enable us to halt, and reverse the current decline in pollinator populations as rapidly as possible. Let us begin at the highest level and proceed down to earth, where real action is to take place.
The policies:
I. The recurrent necessity here as well as elsewhere, is to ensure that all policies formulated by an authority at any level are congruent with reference to each individual goal they are intended to serve. For instance, a ‘free trade’ policy to ‘improve’ the economy that permits the import/manufacture and sale of none-selective biocides is not congruent with either a policy to protect pollinators or one on improving bio-diversity. In some cases, much may be done to protect pollinators by striving to achieve this objective.
II. Formulation and implementation of the problem specific policy concerned with---
A. Ascertaining the qualitative and quantitative extent of the problem
B. Ascertaining the ways and means needed to accord the problem an appropriate priority, design the optimal feasible solution and procuring the resources required for undertaking it.
III. Ensuring its optimal implementation in a way that allows its modification/revision in time.
Strategies:
The strategies one may resort to attain the policy objectives loosely outlined above require no lengthy description. I will not touch upon a strategy for achieving policy congruence because its resolution depends on political consensus whose achievement is beyond the scope of this discussion.
Identification of the qualitative and quantitative aspects of the problem:
Some evidence of the decline in the types and numbers of pollinators is already available, even though it seems to be somewhat fragmentary. However, we have been engaged in activities that disrupt plant-pollinator networks for more than two centuries.
While the study of those networks is comparatively new, we already have reason to believe that regeneration of a critically insulted plant-pollinator network may be extremely difficult.
Moreover, there is much we do not know both about already identified networks and other hitherto unidentified plant-pollinator networks in operation, which do not benefit food or ornamental plants, but which may provide some essential ecosystem service to one or more members of a useful plant-pollinator network. Hence, it is necessary to establish the status of plant-pollinator networks and their supporting networks, especially in the areas where they show a deterioration.
Once this has been established, we can design strategies needed to regenerate/expand plant-pollinator networks and their supporting networks with reference to the natural indigenous flora and fauna of a given area. The possibility of doing this, depends on our having a prior knowledge of what relevant plant and animal species have been indigenous to an area, and to the sizes of their approximate individual populations.
I think this information is vital in formulating a holistic approach to protect, regenerate and sustain robust plant-pollinator networks, but even in industrial countries it is hardly complete or accurate. Moreover, surveys undertaken now can only reveal what is left of such networks, and not what is constitutive of a robust sustainable ones. As such, they cannot provide a scientifically valid indication of what they should be constitutive of, if they are to be robust and sustainable.
Furthermore, there are large gaps in our knowledge of plant-pollinator networks and other bio-networks essential for the well-being of the former. The next area on which we need further information includes what long-term effect biocides currently in use including those of plant origin at high concentration, and the effect of nectar and pollen of non-indigenous cultivars and genetically modified ones on the plant-pollinator networks. Consequences of large-scale man-made mechanical topographical changes and industrial activity on them, are well known.
So, to provide ourselves with more complete information to enhance the general quality of our agriculture/environment policy---
1. Initiate and sustain the conduct of scientifically rigorous field surveys to ascertain the current composition and status of known plant-pollinator networks and to disseminate that data.
We may obtain a working idea of the ecology of many areas of the world from an environmentally more benign time through bibliographical research even though some important works may be out of print now. However, works of the great Alfred Russell Wallace, Alexander von Humboldt, H. W. Bates, etc. in reference libraries would amply repay one’s efforts to reconstruct good deal of the ecology of many areas where pollinators have become scarce.
1. Much basic research remains to be done in the following four areas, which have a direct bearing on the robustness of plant-pollinator networks:
I. Interaction among indigenous flora and the introduced cultivars, and the short- and long-term effects on latter’s nectar and pollen on the local pollinators. When it involves genetically modified plants, such interactions could have highly undesirable results.
II. The optimal qualitative (in terms of species) mix of indigenous plants and pollinators that might be used to regenerate/improve the plant-pollinator network of an area.
III. Research in applied science to identify optimal means of introducing indigenous flora and pollinators to affected areas with a view to re-establish robust and sustainable plant-pollinator networks. Here, it may be possible to use some useful local crops that may successfully substitute a lost or a threatened source of nectar and pollen.
IV. Identify the crops, decorative plants and the indigenous flowering wild species whose flowering is sequential in a way that would ensure the local pollinators an adequate food supply during their adult stage. At the same time, it is important to ensure an adequate food supply to their larval stage.
2. Action at the ground level:
I think it might be useful to place the types of action I envisage I three broad groups, viz., general, sector-specific and finally, more or less individual. Let us begin with the general:
I. Dissemination of the available information to the general public on the seriousness of the situation and what everybody can and ought to do. As research described above becomes available, this information should be updated accordingly.
II. Rural population and some NGO’s and other suitable volunteers may be of use in identifying the local flora and their flowering times, and pollinators.
The sector-specific action ought to include:
III. Incorporating the importance of understanding the local plant-pollinator networks into school syllabi at a suitable degree of completeness. It is best to begin as early as possible and extend it to the schools of agriculture.
IV. Policies to reward environment-friendly bulk transport of non-perishable items like grain, nuts and dried fruits, meats and vegetables, flour, etc., using inland waterways (canals and rivers), coastal shipping, and railways, while penalising their transport by lorries. This calls for an actually environment-friendly national transport policy to revamp the disused canals in many countries, and in nearly all countries to make an extended use of rail transport.
V. An agriculture policy to promote small-scale farming and extensive planting of mixed crops in larger production units. Moreover, a more rigorous control of biocide use is essential, while a moratorium on the spread of genetically modified plants and animals seems to be urgent in view of our lack of real knowledge about their long-term interaction with other organisms including man.
VI. Health sector could warn the public on the uncertainty about the results of long-term interaction between genetically modified food items and the humans, so that a possible re-run of the tobacco controversy may be avoided.
VII. Horticulture sector may contribute by promoting the cultivation of traditional wild-flowers as ornamental plants both in rural and urban settings.
VIII. Local authorities, especially in some rural areas could plant traditional wild-flowers along the roads, commons, etc., as a part of ‘local beautification scheme’.
IX. Local authorities and NGO’s could make a major contribution by engaging in small-scale re-forestation of the barren countryside with indigenous plant species, which is getting more and more important.
At the individual level, there is much we could do to ameliorate the problem both directly and indirectly. While those engaged in agriculture and forestry could make a greater contribution, the others could do more than what they might think possible with a little effort.
X. Halt the removal of hedges, and plant traditional hedge flora along the insides of barbed-wire and other types of fencing.
XI. Land owners could plant small woods in areas of poor soil in their holdings choosing local small trees that do not prevent the appearance of under-growth. When suitable, nut trees offers an excellent choice for this purpose.
XII. Planting pest repellent herbs among crops and areas that separate different crop types. Some herb flowers are very attractive to the pollinators, eg. Basil and Dill flowers.
XIII. Providing simple nesting sites to local pollinators using materials made of natural substances like old bricks and bits of masonry. For instance, a small stack of old bricks with 16 cm holes drilled in some of them would provide an ideal nest for several species of solitary bees. A few early blossoming wild flowers may be planted around such a stack to provide the newly-emerged bees a source of food until they are strong enough to range widely. Here, I deprecate the use of plastic nesting materials, because how plastic polymers and the secretions of pollinators may react, and what effects the products of such reactions may have on the developing larvae are unknown.
XIV. Those who have fences around their properties could substitute or supplement those with flowering fences. Here, it is important to use indigenous plants, and preferably those flower at different times of the year.
XV. Halting the use of biocides on lawns and other formal home gardens.
XVI. Introducing local wild flowers and flowering bushes and shrubs to improve the appearance of the environs of schools, and other public buildings when the space permits.
Now, we come to the question of funding, for some of the suggestions outlined here require a considerable outlay. I will leave this problem in the hands of those who are adept at wringing funds from decision-makers whose parsimony knows no bounds when funding involves non-glamorous projects, but hope this would be of some use.
Lal Manavado.
Mr. Lal Manavado