Some say Larix some say Larch

 

The NY Times has an article about the larix, a tree indigenous to the White Mountains in New Hampshire and other similar locations. They note:

At least, it did. Since the late 2000s, about a quarter of Britain’s larch trees have been infected by Phytophthora (Greek for ‘plant-destroyer’) ramorum, a fungal-like pathogen that spreads via wind-blown spores and water in the soil. “Ramorum is so beautifully good at killing larch effectively,” Dr. Heather Dun, a scientist from Forest Research in Scotland who is studying the pathogen, told me. In the United States, it’s known as “sudden oak death,” targeting native trees like coast live oak and tanoak.

 The NH larix is a hardy tree if you grow it at 1,000 ft above sea level where the frost line in winter exceeds 1 foot! And the soil is very sandy. I tried one in New Jersey in clay soil and a frost line at best a few inches. No luck.

Trees need certain soil, certain moisture levels, and certain temperatures. My ginkgo loves clay soil in NJ but hates sandy soil in NH. My white pines are weeds in NH but struggle in NJ. 

Trees are very sensitive to location. White birch hate NJ but love NH. The list goes on.

Now for diseases, they all too often  result from some one bringing it into the region or country out of gross ignorance! Put it in their garden, wind blows and devastation occurs. 

Isolating the killing factors is complex but usually no single cause is present. 

 

Ontogeny Recapitulates Phylogeny, or What Comes First, the Chicken or the Egg

In Nature there is an article where they are applying the AI worlds approaches to plant systematics. Namely the process of sorting and arranging plants. They note:

There are roughly 3,000 herbaria in the world, hosting an estimated 350 million specimens — only a fraction of which has been digitized. But the swelling data sets, along with advances in computing techniques, enticed computer scientist ... and botanist ..., to see what they could make of the data. ... team had already made progress automating plant identification through the Pl@ntNet project. It has accumulated millions of images of fresh plants — typically taken in the field by people using its smartphone app to identify specimens. Researchers trained similar algorithms on more than 260,000 scans of herbarium sheets, encompassing more than 1,000 species. The computer program eventually identified species with nearly 80% accuracy: the correct answer was within the algorithms’ top 5 picks 90% of the time. That, says Wilf, probably out-performs a human taxonomist by quite a bit.

Now having done this a few decades ago,  and still proceeding to do so with Hemerocallis, the answer is not form but simple genetics. Sequence the genes, then using a mutation hypotheses base determine how the genes evolved. The use the shapes to see the effect. As is well know this process has been around since Linnaeus and it suffers from substantial defects. Just because a form looks close to something says nothing about the genetic evolution.

Ginkgo Nuts, Biodiversity and Climate Change

Some twenty five or so years ago I got some ginkgo nuts from the New York Botanical Garden. I planted them and last year one of the trees, a female, was filled with nuts. Fantastic. The squirrels did not seem to have any interest, smelly seed coats, but well that was not the end. Come Spring, the coat had gone and the squirrels managed to consume every one! The ginkgo has managed to survive some 100 million plus years but it had not faced the squirrel.

Now as we go further north we see the grey squirrel also going there as the warming occurs and thus many flora that were dependent on small consumption by red squirrels will be under siege by grey ones. The issue of changing and complex biodiversity means that there will be challenges to flora and fauna.

I make this comment because I have read a paper by Dr. Victoria Karchenko at The Botanical Garden Institute in Vladivostok where she states:


Now the climate changes become more pronounced. This affects to biodiversity and distribution of plants. Therefore, we need to study of the biodiversity and trends distribution of plants in specific environments. In this connection is necessary to clarify real composition of species in the of regional floras potential of their variability of and disseminating. A pressing problem remains the creation of a unified database of the flora of Russia, which takes into account the data of regional studies.  Research program allows executing posed problems if it would coordinate with other botanical gardens. This program will allow revealing structural and functional adaptation of species to various environmental conditions. This will help create a basis for design ways to regulation the development of plants and biotops.

As I had indicated, the paper by Dr. Kharchenko presents a very compelling argument for the development of a detailed flora for Russia especially the Eastern parts. We have been using certain sentinel plants such as Hemerocallis which are native to this part of Russia to measure long term climate changes. It is essential to have a detailed data base not only of the flora per se but more importantly an understanding of their propagation status based upon the balance with pollinators as well as fauna which may consume the plants before they can complete their re population cycle. We have seen not only a shift in bloom time and divergence with pollinators but more importantly animal predators on plants growing in numbers. This is a critical study especially in this highly bio-diverse area.

Eastern Russia is an relatively unexplored treasure trove of biological species. Many of my Hemerocallis are from there and there are still new species of that genus being discovered. However there may have been a balance in biodiversity for millennium but as we see warming we would expect drastic changes. To understand the changes we need a baseline and the proposal to establish such a well defined baseline is essential. There clearly should be substantial support for this effort, since one would expect the time scale for change to be quite short.

Some Thoughts on Plant Evolution in The Urban Jungle

Plants evolve, often more rapidly that animals. We may not notice it since we don't look closely at them. But they do. In a recent paper on plant evolution in The American Journal of Botany the authors remark:

Why might urbanization infl uence plant evolution? Clearly, urban development changes both the biotic and abiotic environment in ways that could alter natural selection and adaptive evolution within plant populations. Urbanization may also infl uence nonadaptive evolution due to altered gene fl ow, genetic drift, or nonrandom mating. For example, urban development causes habitat fragmentation given that buildings and roads are a common feature to every city, where extensive pavement, concrete, and alteration of natural habitats is the rule rather than the exception. Th is fragmentation can limit dispersal and gene fl ow,  leading to greater genetic diff erentiation between populations. It can also infl uence the size of populations and thus the importance of neutral evolution because genetic drift will be greater in  smaller populations. Finally, urban areas can alter mating patterns (e.g., increased selfing) through changes in pollinator communities...

 The authors then make several predictions:

1. Urban and non-urban populations will diff er in the amount of genetic diversity
2. Urbanization will alter natural selection on populations
3. Neutral evolution will be greater in urban areas
4. Genetic divergence between urban and non-urban populations will be proportional to the size of urban areas
5. Insect-pollinated plants will evolve greater selfpollination or clonal growth in urban areas

Now I would argue a bit differently. The primary influence on urban diversity will be driven by humans. Humans select plants that they like, like the triploid Hemerocallis. They become invasive via human attraction. They are sterile but aggressive growers pushing out other plants. They are a typical invasive species. Also the introduction of foreign species may very well lead to cross breeding that would have been impossible otherwise. Yet successful growth may be inhibited. Also the use of pesticides and similar plant control biotics will cause a shift in classic evolutionary manners.

Thus the five predictions above I believe are at most a small part of the complexity of urban development. For example I have more than twice the tree species on my small acreage than indigenous plants would provide. Some of the trees are quite hardy and aggressive such as Ginkgo and Metasequoia.

I believe that a more details analysis and monitoring would be quite useful, and that what the authors propose may be quite limited.